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: Ski Doo Tech Info


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800MXZ
04-08-2003, 01:12 PM
I for one think we have allot of great minds here on this forum, and want to take advantage of it and get some topics started.

I am starting this thread to see what the guys in the Doo forum want to talk about, and then I will start a thread on it.

porting, Clutching, pipes, etc.... what do you think?

I for one would like to talk or do some explinations on Shimming vs Porting, as I have recieved allot of PM on it lately.

Machzzzz1
04-08-2003, 01:30 PM
I say we talk a little about pipes.

There seem to be many brands and types and all put diffrent advantages on the table.

For the Mach Z I would look at Crankshop, Jaws, PSI, and such. PSI claims to be the best. They say that they have out done them self with the triple pipes for the mach. But yet everyone still uses crankshop and jaws. Why? What advantages do you have.

Also what about for the twins. 600ho, 800. What pipe works best on them. what do they offer you.

And lastly how loud are each of the pipes. Can they pass as a stock pipe or are they screamers.

For the price of a new set of pipes we sure dont know what were getting till its on and running. :(

machz69
04-08-2003, 01:52 PM
yeah i think this would be a pretty good topic. all the good stuff. and pin it

jawz
04-08-2003, 02:06 PM
What about the difference between trying to beef up a smaller sled versus just trading up to the bigger motor. I see it all the time guys with 583's and 600's talking about aftermarket and hp gains and the such. How about save your money on aftermarket upgrades and trade up to a bigger machine. When I was buying the Rev, I just couldn't see myself on a 600, even though they are a great motor. Now if the 800 isn't good enough for me, well... I think I might have a problem, I could always put an 800 triple in the rev. :D

rob7374
04-08-2003, 02:17 PM
Personnally I think clutching would be a great one. There are too many people out there that just do not know about properly setting up clutches. Usually this is not because they can not do it but they lack the tech info to make the correct choices. Heck with riders changing brands to ride the REV's a whole new batch of people will need to be educated on the TRA clutches and the RER secondary. Remember it doesn't matter what you do to your engine if you can't clutch it effectively your mods are being wasted.

idooski
04-08-2003, 02:47 PM
I don't know where you come up with such good ideas sometimes Dave. Another winner.

800MXZ
04-08-2003, 03:07 PM
what I am trying to accomplish is to have the members start to bring their good info to the table and bring it out in the open.

We have allot of great minds here, lets use em!

Like the Mach pipes are a good idea, then Marty should start a thread on it.

Revguy
04-08-2003, 05:13 PM
Hey guys, I heard that Jaws makes some of the pipes for Crank Shop. As far as the triple pipes, I think Jaws and Crank Shop is the way to go but, just as rob7374 said, the clutching has to be spot on for anything to work properly. Heck I think doing just clutching is money ahead of buying noisy pipes. Some pipe manufacturers say you gain horsepower but in reality on the dyno, numbers don't lie but some pipes make you lose power.

permafrost
04-08-2003, 05:25 PM
I for one would like to see info on clutch maintance and tuning. Maybe an article on the Team Roller secondary.

RNM2399
04-08-2003, 05:27 PM
I agree with Idooski. You think 800MXZ is just one of those unshaven hillbillys and then he comes up with all these great ideas. LOL Dave!
Ryan

mxz800
04-08-2003, 05:32 PM
i would like to talk about heads and shim kits rk tech or cudney ? pistons new ring on the stock or new 2 ring pistons from weisco or any other brand name ,,,whats the up side and whats the down side..i have already bought the ones that i want but i like to hear from everyone else.

Mikadoo
04-08-2003, 06:57 PM
I too would like to hear some opinions on clutching.
I need help in understanding what different spring poundages in the primary do, also all the different ramp profiles.
Here is a setup I want to try next winter on my 809Z
280 ramps
200-380 spring
19gm pins
50/44 helix
21-23# tention
24/44 gears
230# rider
1 1/4 long track
stock pipes, stock engine
I just want a good all-around go fast set up, not all out racing only.
Any opinions??

machz69
04-08-2003, 09:18 PM
i havent had real good results with the 280`s i found that they just fall off to fast but i will play with them i a little more this summer.

800MXZ
04-08-2003, 09:31 PM
Trick to the 280s is running a flat finish on your cam. Ramps have a direct relation ot how the sled shifts out, and a steep cam cant happen with the 280

That setup is pretty close to what I have in my mach, I just tune the primary to pull 8600 to match the pipes.

machz69
04-08-2003, 09:40 PM
see my sled is an rer so i just stayed with the stock cam 47-44 so it should be close then i also tried a reg secondary with the 53-44 and a couple of cams that im not sure of the angle but still found it pulled hard for like 400 feet then just fell off. and the other thing was traction very hard to get it to hook with the hard engagement

Mikadoo
04-08-2003, 09:51 PM
MXZ800, So your saying the 44 finish angle is good or would you rather see a straight angle like 47? What part does a stiff spring finish, in this case, 380# play into this?

mach69, when you say falls off, do you mean it goes like hell in the begining then just mellows out or quits pulling hard at the end? Would a 286 or 295 be better suited but pull as hard as the 280? What about top end losses with the 280 or the others with that spring?

doo900
04-08-2003, 10:15 PM
i ran 280's in my 900 twin all last year on asphalt with a 230- 410 w/ 21 pins and a 54 helix at 20 lbs on the beige spring and ran 6.22 @106 mph in 660 ft . now i think the 280 ramp does stop pullingat 500 ft so i am trying 287's with this same set up to see if it pulls longer . my stock z ran good with 228 230-380 18 pins with a stock 50 @ 18 lbs it ran 6.63 at 100 mph in 660 ft .the 96 z is hard to get out of the hole the best 60 ft was 1.43 , the mxz does a good job @1.36 in 60 ft

machz69
04-08-2003, 11:46 PM
yeah mikeadoo that is exactly what i am saying. but even on asphalt i found it would spin like a mother.....lol.... im still trying to find a good set up for that. i would like to engage at around 3000 rpm. but i think the 286 will be much better

kennypope
04-09-2003, 06:54 AM
Jaw's pipes are good, but for customer service, not so good......the only one that ever seems to know what's going on is Greg himself..........and try to get a hold of him...........good luck.
Maybe it's better now but this was 2 years ago when I was still a triple boy.....now I've mellowed out to twins.

800MXZ
04-09-2003, 09:17 AM
What I have noticed is that one can not just change to 280 ramps and throw their hands up in the air when it doesnt work just right.

The shift out dia on all the ramps are the same, so they will theroeticly will go the same MPH. The 280 is very agressive, so agressive that if not set up correctly it will not shift out. I dont know how to exactly get it into words, but verification that the clutches are shifted out are necessary to know if it is working correctly.

On my MXZ, I have to run reverse cut cams with the 280s. The 280 is so agressive that it can't shift effeciently, so a shallower start angle is needed. On my Mach I am running 48/44.

Now, strait cams vs compound cams. In the post above, we compare a strait 47 to 50/44. A strait cam shift wise is much more agressive than a compound cam. Since we need to start at one angle, and finish at another, the actual profile of the cam looks like a "L" and has a step in the middle. A strait cam is from point a to point b, thus making it shift more aggresively. It took me a long time to figure this one out. In my testing, a strait 50 was more agressive in the middle than 53/47. I will see if I can find an article that I read on it in SnowTech.

800MXZ
04-09-2003, 09:22 AM
In this chart, it shows at every clutch ratio the distance the sheeve has opened (sheeve displacement). This is for a strait cam. it is linear, or a strait line. This is a strait 47 cam.

800MXZ
04-09-2003, 09:25 AM
now this is a 53/47 compund cam. You will see the initial shift is very aggressive, but the closer we get to the finish it is very lazy. Thus providing lack luster top end, or very slow shifting. The larger the differential from start to finish angle, the worse this is. Great holeshots, just no top end cause it takes a long tim to shift out.

machz69
04-09-2003, 12:01 PM
awh but u see why it should go to the shallower angle on the top is that the more shallow you are on top the more speed u should get. thats why most cams are like that steep to shallow. shift up quick and still have top end. but i have also tried stuff like go shallow off the line then shift up quick just to try to get the sled to hook up

jbird90
04-09-2003, 12:46 PM
I could go for Carb Tuning 101.

As well as Clutch tuning and how to determine what angles and springs to use

Mikadoo
04-09-2003, 05:01 PM
So your saying to find the best straight angle helix for your application to achieve best top end? Only thing I can see wrong there is most races are won off the line. This is where a steeper start angle would be the advantage, at least I thought?
I could see an angle like 53/44 that came stock on a Z being that problem but 50/47 should work good with the closer numbers then?

One thing I noticed last season with my sled is when you pin it, the tach would slam 8500 then drop back to 8000 then climb to 86-8800.
With a straight 50 it would slam 8200 and drop to 7900 then climb to 8800. This is why I want to try a 50/44 helix, the 44 knocking down the 8800 to I hope 83-8400. This is with 200-290 spring and 286 ramps.
I'am sure by changing to 280's and a 200/380 spring I may be looking at a whole new can of worms.
All I want to do is be able to pin it and have the tach hit 8300 and stay there all the way to the top!! Adding and subtracting pin weight along with clicking up or down only "fine" tunes it.
I have never owned a Skidoo that could do that, always OVER-REV!

800MXZ
04-09-2003, 07:20 PM
I am saying that helix vs ramps is important.

Also, never tune RPM with the 2ndary

only the primary

CORY9
04-09-2003, 07:44 PM
Hey Guy's
Before you "old-time sledders" get all bent over the specs how-bout starting something on clutching basics 101!!!!
If there's one thing I've noticed on this site it is that the majority of interest is on hi-performance sleds. There are a LOT of us, very mechanically able but slightly nieve sledders out here who need some basic advice! Yes I want my sleds to perform better via clutching, just tell me how!!!

800ski
04-09-2003, 08:44 PM
Mikadoo, What do you mean you can't get your sled to stop overreving. I have always been able to get the rpms down where i want them,by using adjustable weights. Usually the reason i had problems holding rpms was because of tractions problems. Also i have a staight 47 if you would like to try it.

kid rocker
04-09-2003, 10:59 PM
Dave, I disagree with you on tuning the secondary for rpm's. Sometimes spring tension in the secondary can change the rpm's that you need to stop your belt from slipping. Your right normally tune your rpm's on the primary but not always. :D

JETRep
04-09-2003, 11:24 PM
Mikadoo,

Click here (http://www.developer10.com/~john/primary_spring.jpg) for a page from the Doo race manual about primary springs.

machz69
04-10-2003, 09:26 AM
yeah om cats i would tune the secondary just a little for more rpm but also just to have a little more pressure. now my sled is a very good example. i have an rer so you cant adjust the lbs on the secondary. that is probably why the rer just runs a little better then standards.

Mikadoo
04-10-2003, 06:09 PM
Hey, thanks guys, this is really getting fun!
What do you think of a roller secondary? Would it be a totally different set up than a regular clutch?

800ski, sure I can stop my sled from over-rev at the price of low rpm.
Pin weight and clickers are just a small part of the tuning tool and I'am trying to find the right combo of everything involved to get a constant set rpm with no climbing on top yet have peak rpm for full power. Damm difficult with a TRA!

machz69
04-10-2003, 06:26 PM
well you see mike that is a whole new thing again because it does shift up way fast. but the up side is as fast as it upshifts is as fast as it backshifts wich is good for trails or is it?... see i believe that this is why cat is having such a hard time getting there big sled going. first thing i always do with them is go with a standard secondary. in reality slowing the shift. see the basics of all clutching seem to be weight in the primary but still have top rpm. so what i have ended up with is my stock ramps with a heavier spring and then the heavier pin to bring the r`s back and give it more side pressure. with the tra im starting to see that not only does the profile help but also the lenth of the ramp. thats why with my stock ramp it is almost identical as the 286 but with no sort of stall notch and it is longer = a little lower engagement and smoother.

machz69
04-10-2003, 06:28 PM
someone had asked for the basics in clutching.... what r you looking for? give me a starting point of where you want to start and im sure we could help clear it up a little.

800MXZ
04-10-2003, 06:29 PM
KidRocker - Given no belt slip on the secondary, RPM should not change with changing cams. Obvoisly if one loosens up 2ndary tension and RPM starts to fluctuate, it is an obvious sign of belt slip. IMO that would be the first thing to look at on Mikadoo's sled.

Right from the doo race manual, don't use the 2ndary to tune RPM.

Now if a guy adds cam angle and the RPMs fall off allot during accel, it is too steep. But in all the tuning I have done, I have swtiched from a strait 47 to a strait 50, and RPM did not chage with the same 2ndary tension, just the speed at which the sled accelerates.

Machzzzz1
04-10-2003, 06:38 PM
Dave is right. You never use the secondary to adjust RPM. Belt slipping can mess up the RPM and all of that is adjusted from the primary by using diffrent pin weights. If your getting all sorts of diffrent RPMs stop and feel the belt. Its going to be hot and thats from slipage. Im not that well informed about clutching but what I gather from the people that do, this is 101.

machz69
04-10-2003, 06:55 PM
well 800 i have to go the other way on this one....lol.... when i change cams i do see different rpm. now i usualy see that the rpm lowers when i go with a steeper cam but in the bomb race manual they say that the smaller cam will result in less rpm and the steeper will result in higher rpm ....lol...... so there you have it but anyway u look at it there should be a change in rpm.

Revguy
04-10-2003, 07:51 PM
Here's a set up that worked great for me when I was racing a Mach Z

230-350 primary spring
20.5 gram pins (23.5 grams if you wanna use magnesium arms)
50 degree helix, set driven at 17-18 lbs preload
286 ramps
stock gearing
stock jetting (depending on air temp)
stock track (1.25" slows you down)
get a set of those trick cam shoes from Goodwin with the teflon insert

This set up works GREAT !

Revguy
04-10-2003, 07:54 PM
Hey MachZ69, the race manual is incorrect. When you use a steeper cam(helix) it decreases the RPM's, and vise versa with a shallower cam. That is a typo error in the race handbook. I've raced many years, I know this kinda stuff

Mikadoo
04-10-2003, 09:30 PM
Well I just spent 1/2 writing a big ta-do and the damm computer jump off-line a WRECKED IT ALL!!!!!!!!!
In short, I agree with machz69 that the lower you go with your angle the less rpm. I have provin this time after time to myself, this is why I'am going to a 44 finish. Every degree you drop you decrease rpm by 150-200. I'am looking for a 600 decrease in top r's.
I also agree belt slippage can cause erratic r's too so by what I have learned here more pin weight and stiffer top spring #'s is good.
Keep up the comments then we can try a new subject and learn from that.

This is a great idea that got started! SWRules

machz69
04-10-2003, 09:48 PM
well rev guy you are running somethins close to what i have recomended to a lot of people but with the pin weight and spring that you gave i wouldnt be able to get my rpm with that cause right now im running like i said my 295`s with a 230-380 and 19grms and i am at 8450 rpm.. if i had that spring and pin i would be low. now as for the track what track are you talking? cause im running the 9818 and it does seem to run pretty good. now if im on ice then a speed track is the was to go. and one other thing to think about....hehe i run the 286 ramp i have to set the clickers in the 5th with the 230-380 spring and 19grm then i change over to the 295`s now i have to set my clickers in the 3rd..same spring same pin same cam different r`s ;)

dino
04-10-2003, 09:54 PM
Revguy: The set-up you listed is the same as mine,It also works great for me. From engagment to a solid 8400 rpm shift, also cool clutches = no slippage.Dino

machz69
04-10-2003, 09:57 PM
where the diference might be is that mine is an rer.

kid rocker
04-10-2003, 10:00 PM
Dave, I have read the racing manual over and over. You are right, it does say not to adjust the rpm's with the secondary. However, in the "real" world it has worked out good for me. But then again, I don't know anything about clutching. LOL... If you change cams you very well might see a change in rpm's as machz69 states. I agree with revguy on this one.

FlyingDutchman
04-10-2003, 10:29 PM
The idea of more tech info on this forum is a great one. I also agree with the subjects already suggested i.e. Engine mods and Clutching. I think for most folks the Clutching topic is a vast Black Hole. I understand the principles and theories of clutching, but I wouldn't want to run down to my local dealer every week to buy and try different components. I think this is the best time of year to dial a clutch in however. Grass or Asphalt provide a more consistent base for time trials. The time clock is the only true measure of performance improvement with clutching. Unless you can try different set-ups at the Drag Strip or use an elaborate timing system it's only a gut feel if any peformance improvement has been achieved with trial and error. Another less mysterious topic could also be the track. There is a host of aftermarket tracks available and traction aids. What works best, in what conditions. Somebody with a track that looks like a bunch of snow shovels tied together can embarrass a very hyped up sled! :nervous:

dooman
04-12-2003, 02:58 PM
Originally posted by machz69@Apr 10 2003, 05:55 PM
well 800 i have to go the other way on this one....lol.... when i change cams i do see different rpm. now i usualy see that the rpm lowers when i go with a steeper cam but in the bomb race manual they say that the smaller cam will result in less rpm and the steeper will result in higher rpm ....lol...... so there you have it but anyway u look at it there should be a change in rpm.
steeper the angle the faster the upshift,therefore loading the motor harder.as 800mxz stated the reason your seeing the rpm loss is your motor is not building enough power to pull the helix.primary spring,all variables kept same only changing spring the higher pressure will yeild more rpm in each ratio.kid you know clutching? ;)

john breedon
04-12-2003, 11:05 PM
I have tried literally 20-30 clutch combos over the years(mach z)and with out making it sound overlly simplistic here goes,any set up that(with the tra)can be clicked down to the point where it falls off peak torque then clicked back up to stay on the pipe is as good as it gets.You can try heavier pins,then shallower helixes,or big helixs with lots of preload in both clutches and less agressive ramps.All in all the clucth parts guys are getting rich.and most guys get so far out in left field they dont know which way to turn.What i would recomend doing is leaving everything stock and putting in adjustable pins,keep adding weight till it pulls the engine down too much or it wont back shift propelly.Than you could try a little more helix to see if it will pull it(multi angle)for the hole shot.

paidncash
04-13-2003, 01:28 AM
Often times all you need to do is keep your clutch's stock and just add some pin wieght. Turn your clickers down to one then start adding wieght until you cant pull your rpm's anymore, now all you have to do is turn your clickers back up to two or three and you should be right at your correct rpm's. It's amazeing what a little extra belt squeez will do for your sleds performance.

EAGLE17
04-14-2003, 11:37 AM
I have a 2002 mxz800 with mods by DNE performance.Since day 1 this machine has over-reved.None of DNE's set-up have worked and now I have a Cudney kit
and it is still over-reving.Bill Cudney told me this is due to running the stock 127 belt.He says to run a ski-doo 067 or a Dayco Ultimax II.I have not tried it due to no snow but my question is can a belt make this much of a difference?It is pulling about 8500-8600 rpm's on the tach and it should be stock rpm's.I run dead even with a stock 800 and find it hard to believe that a belt change will make that much of a difference.Any thoughts

machz69
04-14-2003, 08:46 PM
yeah thats sounds like its a little high in r`s what is the mxz8 supposed to run at? isnt it like 8000? not sure but yeah i agree keep it simple. i like to change one or 2 at the most things at a time.

800MXZ
04-14-2003, 08:57 PM
I personally like the 067 myself and the Dayco. I have used both. I dont think the Dayco is as good perf wise, but for trail riding you can't beat the price.

Sounds to me if several setups arent working, then we might be having a issue with the secondary that is making it slip. Is this a RER sled?

I know MXZWFO had allot of problems with his 2002800 with mods and the RER. Since the RER has no torsional twist on the helix, he was actually pulling the buttons off of the helix during holeshots.

Limskii
04-14-2003, 10:33 PM
EAGLE17, I would think that your belt is slipping also. I've had this problem many times on my Mach 1. When you are DOOing some clutching and testing, like acceleration and top end runs, always stop and check prim. and sec. clutch temps after 3-5 test runs in a row. From my experience, the 127 belt (which is a stickier belt), could be made to work real well as a short drag race belt or deep snow riding belt to reduce slippage and temps. The 127 belt would probably require a higher clicker pos., lower pin weight, and/or a little looser secondary tensions compared to the 067 or a Dayco Ultimax II, which are both harder compound belts. I have found the Ultimax II's very reliable if properly broken in, but belt length consistency and top width wear to be a problem. The 067, I find to be the best belt that I have used on my Mach1. The 067 needs a little more pin weight, a lower clicker and higher sec. tensions, but when properly clutched, provides very good drag racing, very good top end, and very good life if properly broken in ( 15-25 miles of low to med. throttle fluctuations with no drags or top end runs ). If, when clutching, your getting the proper revs. or overeving and you check the clutch temps, a hotter primary compared to sec., means the prim. is slipping and you should either add pin weight, click down, find a lower top tension prim. spring, or find a ramp that is slimmer all the way through and/or has a shallower top end to squeeze the belt harder. A hotter sec. means it is slipping more and you must either increase spring tension and/or go to a shallower cam angle to increase belt squeeze. If your revs are too low, usually clutches will be cool, so you must either lighten pin weight, click up, go to a higher top tension prim. spring, and/or a less aggressive ramp in primary or to a lesser degree, change sec. cam to a shallower angle. The last clutching changes for a low reving engine, should only be tried if you know your motor is making max. power (jetting correct, exhaust valves working properly, compression good, motor alignment good, motor mounts good, timing good, belt good). There are many things to check on the sled to make sure it is making the best and most efficient power that it should be making before attempting clutching changes. This is just my experience and my opinion, but hope it helps ! SWRules

kennypope
04-14-2003, 10:44 PM
great to see the wisdom of LIMSKII is back!!

john breedon
04-15-2003, 12:02 AM
Ill probably get in crap for giving this set up out on my buddies sled but here goes,Dne ported engine (mx800)works great but his clutch kit is way off.301 ramps(280s wont work right)200-320 primary spring with goodwin pins at 20 grams(this is for a 150lb rider,would have to come down lower for heavier rider,straight 50 rer helix with the updated sec spring.27-43 gears.This sled now beats f7s and zr 9s.I may be wrong about the ramps,but use what ever came stock.

800MXZ
04-15-2003, 11:43 PM
I didnt think 280s would work, till I had a conversation with Greg Goodwin ;)

idooski
04-16-2003, 09:53 AM
280's will work. It all depends on what you want to do. Same with the stock s/u. It will work, but... Some of aren't happy with the stock set-up. If you want a corner to corner sled, the 280's and a reverse helix are hard to beat. John... as far as your buddies s/u goes, he's got nothing to worry about. There is nothing special there. As with any other s/u. Nothing special. It may be special for his sled and weight, but may not work at all with another sled set up with the same mods. Everyone wants to know what you are running for clutching. What they should be asking is... how did you arrive at your current clutch set-up? Again, the 280's will work. You need to go to a higher rate primary spring, gear down (a 27 top gear won't pull it), a secondary spring that has a higher rate at the start and a softer rate at the finish to help with the shift, and a reverse angle helix. Remember, this is for corner-to-corner, 90 MPH in a heartbeat. If you want to run on the ice, then you need something more along the lines of Johns s/u above. Just my opinion.

machz69
04-16-2003, 10:34 AM
yeah that is one thing that is very important that we have not mentioned here... that is what are you doing with your set up?... i like to have hard acceleration and still have very strong top end. now i do realise that i could possibly get a little more out of the bottom or just the top but not out of both......hehehe.

revrnd
04-16-2003, 11:45 AM
Something that hasn't been mentioned here is tach calibration. Stihl sells a digital tach that you clip over 1 of your plug wires. Divide the reading by 2 for twins, by 3 for triples.

Run the sled thru its RPM range & check the Stihl tool for its reading @ certain increments.

800MXZ
04-16-2003, 12:13 PM
Idooski - I take it you like that Helix I sold ya? :D

idooski
04-16-2003, 12:13 PM
Good point revrnd. All should have their tach checked before doing any serious clutching.

800MXZ
04-16-2003, 12:28 PM
I sure know if i had a set of factory race pipes, ported, and the factory clutch setup for the combo I would be happy right Idooski?

I wish I could have seen it run.

idooski
04-16-2003, 12:38 PM
Factory pipes?---------Ported????--------Factory setup?????? Whhhaaaat???

Who said I had all that? :p

Actually ended up cutting a different helix based on the reverse I got from you. Now, that's a secret that you won't get from me right yet.

Still need a diff MPEM to put it all together.

RNM2399
04-16-2003, 12:55 PM
Why do the 800s seem so hard to clutch? It just seems to me that with most motors theres a few setups that most people use but with the 800 twin people are all over the map. Any theories?
Ryan

machz69
04-16-2003, 01:45 PM
i can tell you that.... its because they havent been out long enough... now the tripples have been out so long?.... after a while it boild all down to a couple of set ups. now give the 800 twins a couple more years and it will be the same..

RNM2399
04-16-2003, 02:46 PM
Its going on four years though, seems like long enough to me!
Ryan

800MXZ
04-16-2003, 04:18 PM
Probably cause of the incansisntancy of the engines, some run, some dont

machz69
04-16-2003, 04:47 PM
yup going on 4 but not 4 yet so its 3 years.. the first year is just a right off with the other #### going wrong with them... they just go the engines and clutchs to stay together. so yeah by next winter it should be close

idooski
04-16-2003, 05:31 PM
I think part of the reason there are so many different setups is that people want or expect their 800 twin to do more than it can. So they keep on changing things until they get tired of it and decide that it's running pretty good where it's at.

There are several different set-ups that will get any given machine from point A to point B in the same amount of time. The differences in set-up would show in split times. So...again, it's what do you want to do with your machine and at which end of the spectrom
would you like it to be the fastest?

machz69
04-16-2003, 06:40 PM
yup u said it idooski there are many trails that end up at the same watering hole.......lol. as for being the fastest well..... im not very competitive....... my compettition is........hehehe ......... :devil: ;) :p

Buddy of Jawz
04-16-2003, 11:10 PM
Originally posted by jawz@Apr 8 2003, 01:06 PM
What about the difference between trying to beef up a smaller sled versus just trading up to the bigger motor.* I see it all the time guys with 583's and 600's talking about aftermarket and hp gains and the such.* How about save your money on aftermarket upgrades and trade up to a bigger machine.* When I was buying the Rev, I just couldn't see myself on a 600, even though they are a great motor.* Now if the 800 isn't good enough for me, well... I think I might have a problem, I could always put an 800 triple in the rev.* :D
He sees it all the time because he was one of them. :doh: Larry's told him to buy an 800 when he was finished listing the upgrades. :D Am I right Jawz? :sly:

jawz
04-17-2003, 09:54 AM
I have turned a new leaf and instead of dumping cash into a 583 I thought I'd try dumping it into a Mach Z. Same result, thinner wallet.

:(

tb2
04-17-2003, 05:45 PM
I think they have a ring seal problem. When a motor has a high leak down the motor will be down on power, and inconsistant to clutching. Compression test is not an accurate indicitator of engines condition. Late release 2000, 2001, 2002 and now 2003, Not a good sign that after all these motors they are still haveing performance, and durability issues. Im not plunking down my cash untill they get it right!

Fast Mach Z
04-20-2003, 07:42 AM
I have to agree with Idooski and John Breedon. Most, yup, that's right most of the guys playing with their clutches (on stock or near stock sleds) have them so far out of whack it is AMAZING! I have raced every kind of sled I could get to race me in stock or near stock form and the toughest races were ALWAYS the guys who left the clutches stock, or did some "fine" tuning without a bunch of major changes. Also, a HUGE problem is guys changing more than one thing at a time. You can't tune a clutch when you make two or three changes at once. This goes the same for the suspension.

I just want to give you guys some real down and dirty lake/trail racing observations from my experience. The 800 Doo twins in the REV that I met that were stock and still very new, less than 1000 miles on them were very good running, even though the owners thought they needed "more" because of a well running 900 Cat twin or "whatever" sled beat them. I think they expect far too much out of the 800 twin (in my opinion) When in fact they have a very nice quick running TRAIL sled.

The bottom line is to only make one change at a time and make sure you have a verifiable, repeatable way of measuring your performance increase or decrease. That will teach you a lot.

On belts, I had my head handed to me by a belt change. I went from my "perfect" setup on a Doo 066 belt to a Dayco Ultimax III and lost 1000 rpms, that's right 1000rpms. I thought something went on the motor. It took two weeks of testing from the plugs, compression, carbs, and suspension to find it. Of course, the belt was the LAST thing I looked at since I had the cluches dialed in perfectly when I changed the belt. So, the belt can make an unbelievable amount of difference.
This is a great thread that we should keep going. You have some VERY good tuners posting. I always pick up bits and pieces that I use to keep those Cats in their place!

dooman
04-20-2003, 08:28 AM
I don't think asking an 800 twin to beat a 700 is that much ,do you? :0:

Mikadoo
04-20-2003, 03:04 PM
Fastmachz, you said a mouthfull about the belt change. But why did it take you two weeks to figure it out? Not saying I'am a whiz kid or anything, but I knew immeditaly.
Now, if you lost 1000 rpm's wouldn't that indicate the maxIII is a softer belt and gripping better? I thought the 066 was as soft as you could get!
P.S. so which belt did you end up using and like the best?

kennypope
04-20-2003, 03:22 PM
I still don't get it, I've had two 800 twins, a rev and a renegade and put over 11000 km's combined in two seasons and no problems. yet with my 2 previous triples lots of trouble with cranks and so on.
I think tunning these motors is a little more challenging because they have a narrower power band compaired to a triple. You over rev these motors and they fall flat on there face and under rev they lug too much, but you are still better off too under rev than over rev.

It also helps to make sure your tach is on. But from what I've seen with what they did with the blair morgan and what will be on the 04's with the more effcient drive train, bomb is defently on the right track.

Moose Magnet
04-21-2003, 01:12 PM
Originally posted by kennypope@Apr 14 2003, 09:44 PM
great to see the wisdom of LIMSKII is back!!
:withstupid: Where are the diagrams and the pic to go with that post? :p

Good2Go
04-21-2003, 01:32 PM
Originally posted by permafrost@Apr 8 2003, 04:25 PM
I for one would like to see info on clutch maintance and tuning. Maybe an article on the Team Roller secondary.
I would like to see that too, how to maintain clutches and clean them, thats a good thing to know! :D :doh:

Dynamo^Joe
04-22-2003, 02:04 PM
Originally posted by 800MXZ@Apr 9 2003, 08:25 AM
now this is a 53/47 compund cam. You will see the initial shift is very aggressive, but the closer we get to the finish it is very lazy. Thus providing lack luster top end, or very slow shifting. The larger the differential from start to finish angle, the worse this is. Great holeshots, just no top end cause it takes a long tim to shift out.
I total disagree. If you knew what the helix angles were for my 440 & 800 clutch kits I sell, you would scratch your head.

To me "Lazy" is when the signal for backshift is weak and the engine is not quick to respond to throttle position...and/or when the engine starts to lose rpms at highest speeds becuase the clutches are proportionalizing. [Engine loses rpm while clutches shift open - Mph is constant]

The low mph that could be lost is because the helix angle is getting lower yes, the engine rpm is increasing as the clutches shift out.
So since the secondary is resisting the push of the primary causing the low mph and/or diminish in acceleration, what do you have to do to compensate?
...add flyweight.

The thing is that it does not take many grams to get mph back and make engine rpms straight shift.
It only takes 10th's of a gram...whether it is just a few or several.

I try to have a Helix which uses a blend of angles that are used in speed runs and drag racing.
When you look at wide spread angle progressive helix, you can see it starts very steep and smooth out to a low angle.
You know that:
1] low angles produce great backshift
2] Large angles produce great upshift

A wider spread helix will provides an angle that the sled "Needs" at the speed it is going.

You punch the fuel, it accelerates hard...let off the fuel the clutches backshift quickly, you punch the fuel again, you accelerate hard. The clutches have a fantastic ability to grip the belt all the way to and past 1:1 ratio.

Taking temperature measurements will tell a huge amount of information.
The temperature is the clutches telling the tuner that the system is being efficient or not.

Performing exersizes on sleds from 440 to 800cc's, I do not consider say a 53-47 to be a helix that will make too much difference over a straight 50. 6 degrees is not a substantial change to make too much differences in any certain areas.
Now change the helix so there is 15 and 20 degrees, or even more, then yes now you will get substantial changes in the way a clutch system reacts.

Compensating for an engine rpms to climb is just a matter of tuning with adding more flyweight when you want to stay with one clicker position.

You get the benefit of a few things here now.
You have a large angle for upshift.
You have a small angle to keep top speeds.
You need to apply enough flyweight to maintain a straight shift, but the benefit here is having more flyweight mass at low rpms which help use more of the "meat" of the torque curve of the engine to accelerate the sled.
The flyweight is heavier, but now cannot forget that the helix progress to a low angle resisting the push of the primary so the engine will not fall off.

Tuning a highest top speed can be just a matter of either adding 10ths of a gram more/less and/or 2 lbs on secondary pretension.

One of my fave helix's that Dooey makes for all cc sleds is the 53-37 progressive.
Just have to compensate for the symptoms you encounter to make it work good.
I've made some absolute rockets with this helix.
...its not close to what I have custom made, but it is in the same direction.

One may need a 50 deg start angle...but do you need a 50 angle to maintain the highest possible speed?
...probably need a lower angle.
Need a 47 at top speed?...could you have used more at the start of the shift to move you out quicker?

PhiltyPhil
04-22-2003, 02:44 PM
When we are all done with clutches how about suspension mods? As mainly a 30 year plus dirt biker that has always been a great area. Man I remember when dirt bikes had 3in of travel and sleds really did'nt have any. So how about inexpensive mods to your suspension now that it's all pulled out from under and sitting on the bench?

machz69
04-22-2003, 02:49 PM
you have made some valid points here ; everything you have said i pretty much agree with and this is why i think that a shalow angle but that has a coating of sorts to get the shift to shift quick as say a 50 or 52 but still is a 47* for tha back shift. now for myself i do not worry so much of the back shift. if i was an xcrosser then that would be one of concerns but for me its get up and go. i dont realy care what happens after i let off the fuel.... by then the race is over.......hehehe. now i know that on my sled my clutchs seem to run hot and i know that this is not the ideal concept but it does work. the problem i run into is that my sled is an rer so i run in to some diferent stuff such as side pressure on the secondary. but this subject is realy starting to pull out some real interesting things and that someone who may not much experience could be getting some very good info here to help clear up some grey erea

Mikadoo
04-22-2003, 06:07 PM
I can surly agree on the lower angle theroy. I have discovered the benifit of lower angles to stop the dreaded OVER-REV.
Thank god for progressive angle helix's!
Lets talk about getting the "coolest" clutches possible and what it takes to achieve it, ie: more or less primary or secondary spring pressure, pin weights or other combonations.....

Dynamo^Joe
04-23-2003, 12:09 AM
machz69 writes:

why i think that a shalow angle but that has a coating of sorts to get the shift to shift quick as say a 50 or 52 but still is a 47* for tha back shift

Dynamo writes:
PROOVE IT ! ! !
I've challenged many-a people over the years to prove this common statement and they cannot muster up even the most feeble answer to commission what they say. ...but the mfgr says... is the reply 90% will say. The others who have answered could not give me the same answer twice.

On the phone, I've challenged certain manufacturers who make same statement and ask them to prove it...
...for some reason no-one keeps notes of testing, and you get the "brush off".

I have studied and tested and tested and tested and have been disapointed at the results that these coated helix mfgrs have claimed with a coated helix of this number is the same as a non coated helix of this number.

The only redeeming qualit I feel significant to mention is a coated helix will backshift nearly the same time and time again "[i]over thousands of miles than an uncoated helix. The engine-to-throttle position responce was say...slightly quicker over time.
This is a long paper I wrote and dont have the time to write such a novel.
To sum it up, uncoated helix's wear out.
The belt material and dust but especially salt grinds right into the DU bushing on the secondary sliding sheave. These make high spots and grind slots right into an uncoated helix. Now once the helix is worn the damage is already done to the big bushing. Damage to the bushing makes the sheave bind.
With a coated helix the high spots in a DU bushing get worn down and smooth out, the helix just can be simply cleaned with a paper towel and some soapy water.
...no need for brake clean or acetone...etc.
Uncoated helix???....use brake clean, acetone, toothbrush..etc.

I have had brand new 48 uncoated run against say a 48 HRP helix and I could nary measure the difference because my bushings were installed new.
But after moocho testing and dozens of gallons of gas, yes the plain helix condition deteriorated.
..Install coated helix and better results were had.

So I would say yes to a coated backshifts a few degrees lower than a plain helix because I believe that they were mostly compared to worn parts.
For lack of better numbers, I tend to think that a worn 48 helix will work the same as a new 52?

machz69
04-23-2003, 09:40 AM
hmmm proove it.... well the only answer i can give you is its the same thing as installing roller buttons it shifts quicker and when you do put thru the traps the time dont b.s. if its quicker its shifting quicker right?.. with the same angle cam just a little less friction or resistance as would a shalower cam.... done.......;)...hehehe

Dynamo^Joe
04-23-2003, 04:46 PM
machz69 writes:
...now i know that on my sled my clutchs seem to run hot and i know that this is not the ideal concept but it does work. the problem i run into is that my sled is an rer so i run in to some diferent stuff such as side pressure on the secondary.
This is out of the manual I supply for my 440 & 800 mxzx.rev clutch kits.
The secondary spring I use for the 440 has 20 lbs more force at installation and 30 lbs more force on the sheaves at full shift.
With a 99-02 sled in stock clutch form, it is very common in regular winter temps~freezing to see clutch temperatures of 120 to 140 degrees after the exersize I mention here.

Its the Temperature challenge...

BEFORE YOU INSTALL THE S4X KIT........
...go out and do some trial runs with your MXZX/REV with the stock configuration.
Be a little bit harder on it than you usually care to be.
Get on the fuel and get off...back on again and work the sled.
I mean go FLOG THE $#%& out of your sled.
Have a purpose..."Im gonna get those clutches HOT!"
How long you performed this trial run??? 1 minute? 3 minutes? 6 minutes?
...Write the details down.
Stop the sled, pop hood and stick your hand IN the secondary clutch.
****Put the palm of your hand right on the sheave face that the belt touches and count how long you can hold your hand on it. count the seconds and try to be accurate.****
What is the primary sheave temp to touch?

I would like to see the trial performed if you can go and run the sled at 90+mph or as fast as your sled will go...
...Grab the brake real hard...pop hood measure sheave face temp.
I beg you to use a notepad/pen[cil] when you make your measurement/comments.
You will find that you may take more data than you want....which is good.
When you have a conversation of this test, your memory will be vivid and conversation more lucid.

The temperature is the clutch telling the tuner that the system is not being efficient. The warmer temperature is a result of the belt slipping through the secondary sheaves.

The non-destructive testing portion of my job, I have to take temp readings on industrial motors. I used a laser temp gun to measure. I went around and so called "calibrated" my hand touch in "seconds" to the motor temps.
The other two guys in my job use the touch method also and find it quite accurate.

Touching hand on metal:
130 deg F = 5 seconds or more
140 deg F = 4 seconds to "ouch"
150 deg F = 2 seconds to "ouch"
160 deg F = 1 second to BLISTER!

With the S4X kit, you should be able to have temps regularly of less than 100 deg F.
The lower the temperature, the better the ablity for the secondary sheaves to grip the belt. Friction is improved.
The proof is that with the belt being gripped better and friction improved, under acceleration it is not uncommon to see 5 to 6 lengths increase over stock by the high end of the midrange at 70mph.
The belt slips less, the sled acceleration is increased, less hp is lost in the sheaves due to heat.

.....End Of Manual Page.....

Comments:
I have done tests with just purely changing the secondary spring and adding flyweight to compensate for raised rpms. Leaving the stock primary spring and helix the same, we have consistently seen 2-3 lengths over the original beige spring and holding a higher mph in deep snow.
My testing as far as the RER secondary, to lose temperature, I have done it by experimenting with custom made helix's, thus spreading the angles out on the helix making the sheave open up more in degrees over a stock helix.
The helix has a wider spread of angles over stock
...another decrease in temperature was to change the primary spring to one with a higher finish force in lbs.
I have a good exersize we did with some polaris clutches, showing how a beige ski-doo spring worked with much improvement over the stock sil/blue secondary spring. Temperatures dropped considerably, midrange increased considerably.

Fast Mach Z
04-23-2003, 08:34 PM
Mikadoo, thanks for the kick in the butt! You nailed my inaccurate writing.... I said two weeks, but remember, that is only 2 days out looking for the problem in my neck of the country. I had a LOUSY winter. Also, I had other testing going on that was rather extreme and of course, I "expected" a motor problem and then looked for the "motor" problem (2 actual days) until I got my head out of my A#s and started thinking instead of putting my hands on the sled. Sometimes you need to step back and really think BEFORE you tear into it! Lesson learned for me (again!)......
I never seem to learn it the FIRST time........

Dynamo Joe, you brought an issue that I need clarified. If you increase your finish poundage on your primary spring on an RER sled, doesn't that just drop your shift out RPM? How do you get it back up to where it should be? Thanks for the info.

Buddy of Jawz
04-23-2003, 10:40 PM
Originally posted by jawz@Apr 17 2003, 08:54 AM
I have turned a new leaf and instead of dumping cash into a 583 I thought I'd try dumping it into a Mach Z. Same result, thinner wallet.

:(
His Avatar is a pic of me jumping his Mach Z :D

machz69
04-23-2003, 10:43 PM
ok well i guess my clutchs are not that hot then.. but for the most part when i am checking my clutchs is when i am drag racing and or speed running. so they will heat up a little there and then again in the summer on grass and asphalt.

Dynamo^Joe
04-25-2003, 12:32 AM
Fast MachZ writes:
...doesn't that just drop your shift out RPM?
How do you get it back up to where it should be?

Joe Writes:
Umm, Sorry but I do not understand your question. I do not understand what "Drop" means regarding this. =(

I'll just ramble a little bit...
Personally, I do not like the term or word "shift". So many people have a slight few misconceptions or different ideas of the word "shift".
To one person they define this word as one action...another person defines as another action.

I really like to use the word "push" because the primary flyweight pushes the secondary open when the sled is accelerating.

It is very simple to understand that you know what peak rpm you are supposed to run at:
...if the engine is turning below peak rpm, then you know the primary flyweight is pushing too hard and the engine cannot produce enough power to get the desired rpm.
The secondary is not resisting the push of the primary flyweight to keep the engine at peak rpm.

...If the engine is turning above peak rpm, then you know the primary flyweight is not pushing with enough force to open the secondary. The secondary is "resisting the push" from the primary flyweight.
The secondary could be resisting the push because of:
1] the helix angle is progressing to too low of an angle.
2] At whatever shift point the secondary is open, the secondary spring may have too much spring force in its compressed position.
3] Secondary pretension is too much in lbs to let the secondary sheave to shift open. The sheave becomes slower in opening so the primary flyweight must be having a harder time to push.

Whatever force the primary flyweight pushes with, the secondary has to react, resisting with equal and opposite force to maintain a steady rpm.


Now to the spring question:
Lets say for lack of better numbers that you compare two springs with the same starting force.
200-290
200-350
Leaving everything the same in your system...clicker...flyweight mass...ramp...Everything the same but change the primary spring Finish force.

Lets throw a mph hour out there now...50mph "under acceleration".

Test 1
[200-290]The primary spring at 50 mph pushes back against the flyweight with 245 lbs.
You accelerate the sled, you look down at the tach at 50mph...
Your analysis is you read your desired rpm of say 8000 rpm.
You keep accelerating the sled to top speed while the engine maintains 8000 rpm.

Test 2
[200-350]The primary spring at 50 mph pushes back against the flyweight with 275 lbs.
You accelerate the sled, you look down at the tach at 50mph...
Your analysis is you read the engine turning nearly 8100.
You keep acclerating the sled to top speed and the engine climbs to nearly 8200 rpm and top speed is slightly down.

What happened???

In test two, The primary spring pushes back against flyweight with more spring force.
The engine has to produce more rpm to make more flyweight force.
Problem here is that over 8000 rpm, there is a loss of power and the torque drops.
...solution is to make the flyweight push with more force to overcome this extra 25 lbs resistance at 50 mph.
...action is to add more flyweight mass.

Test 3
[200-350]more flyweight added.
You accelerate the sled, you look down at the tach at 50mph...
Your analysis is you read your desired rpm of 8000 rpm.
You keep accelerating the sled to top speed while the engine maintains 8000 rpm.
***You also took note that you reached 50 mph at a considerable shorter distance from where you started***

What happened???
...increased midrange acceleration a little bit.
Why? Using the benefit of having more flyweight at the bottom end of the midrange. The flyweight uses more "meat" of the torque curve of the engine to accelerate the sled.


......... :)

im tired.

Fast Mach Z
04-26-2003, 09:04 AM
Joe,

Thanks for the quick answer to a Bassackwards question. I have to stop getting on here after 5 Pina Coladas..... I did mean "raise" your rpm. Your answer was exactly what I was looking for under Test #3. Also, you gave everyone an excellant overview of clutch tuning! Thanks!

ballsout1
04-26-2003, 01:40 PM
Dynamo, being that you touched on it, what are the spring rates for the doo springs? I`ve got manuels but theres never any mention of it unless you buy aftermarket. Lets see doo has at least 4 springs that I know of white, beige, black and orange, It always struck me as odd that the race manuels glossed over this fine point.

Rocketman
04-26-2003, 03:31 PM
There are spring rates in the references topic at the top of the forum

Krusty
04-26-2003, 05:07 PM
Fully compressed tension, minus installed tension, divided by the distance travelled. Installed length is 2.9 inches. Compressed length is 1.6 inches. Distance travelled is 1.3 inches. ie; Black spring. 410 minus 185 equals 225. 225 divided by 1.3 equals 173.8. For every inch travelled the spring adds 173 pounds of tension.


EDIT; I just re-read your post Ballsout and see you are refering to the secondary spring. Ah well, this is for the primary if anyone needs it.

ballsout1
04-26-2003, 07:33 PM
Krusty, and rocketman, you meant well....

Dynamo^Joe
04-26-2003, 11:09 PM
Hey Ballzout1:

Sorry I do not know the exact spring forces regarding the Dooey Black & White secondary springs.
I do know that from owning the Black spring, this is one wimpy spring. Particularly used in lower power sleds, but especially 1-cyl Ski-doos.
Very weak and similar to the Polaris Red[old red] or Polaris.
I cannot remember the values for the white spring. I do know that it is very comparable to the GW-Blue.
My testing with them over the years they have always produced disapointing results, but that is with me and what I particularly use in detail. Others have good luck with them, but personally I think that the ratio of torsional forces to compressive forces on these springs are too low.

My fave all time secondary spring I have used in Polaris, ACat and Dooey is the CPC - Blue/wht.
At full shift when the secondary is open as much as possible, the pretension torsional values are very high compared to the others mentioned above.

Here is Page 13 out of my S4X and S8X clutch kit manual.
Its simply titled [b]Measuring Secondary Springs.

So you have a Goodwin Blue and your sled starts to top out at 90mph or there abouts. Engine revs at its peak rpm...
You back to your trailer, and make a spring change. You install a Ski-Doo beige spring. The sled is a rocket, yet at about 80 to 90 the sled stops accelerating. One run it holds it rpm for a bit, then drops slightly. Another run, it tops out early and then the engine falls off.

You are back at the trailer and have both springs out on the tailgate looking at both of them wondering "WTF is goin on here"

I helped a lot of sled heads try to solve some of the problems they have and many have been successful in getting what they wanted when they started to measure components and try and relate the numbers to the seat of their pants feel and/or other sleds.

Here we go.

Do you have:
A bathroom scale
Two wooden wedges "optional"
A drill press "optional"

Here is how I measure the secondary springs. I have a small drill press. I put the bathroom scale on the drill press table. Put the spring on the surface of the scale.
When you stand the spring up on its tab, you see that the coil wire is about 1/2 inch off of the scale surface....right? I take the wedge and slide it under the spring so the spring is perpendicular to the scale. [straight up n down] Take the other wedge and put it on the top of the spring so it is "somewhat" level.
Start to bear down on the drill press with the arbor on the wedge and bottom out the coil. Bind the coil. Record the measurement.

For lack of other springs lets use the Ski-Doo - Beige as an example.
You will see that if you bottom out the Ski-Doo beige spring, the value is around 115[lbs] Depending on scale.

You do not need a wedge to slide under the spring. A block of wood will do, a pocket book, a piece of rubber. Anything to put under the coil to promote the spring maintaining a straight up and down movement when compressing.

If you do not have a drill press, you can put the bathroom scale on the floor and prop the spring straight up and down with a chunk of wood or other. Take a 2x4 about a foot or 18 inches long. Put the 2x4 on the top of the spring to compress it. Grab the board on the ends with both hands, put one knee on the board and compress the spring until coil bind. You will know when you coil bind as when you are compressing, the scale will jump and there is quite the unique feeling when you bottom out.
Record the values on a sheet.

Take all the secondary springs you have, measure them to coil bind and record the values.
Here are some examples of some springs I have.
Polaris - Sil/Blu @ 70 lbs
Polaris - Grey @ 85 lbs
Ski-Doo - Beige @ 115 lbs
A Cat - Yellow @ 120 lbs
CPC - Blu/Wht @ 130 lbs
GWin - Blue @ 135 lbs
CPC - Blk/Wht @ 140 lbs
[A Cat - Green] & [CPC - Red/Wht] @ 165 lbs...Approx
CPC - Pnk/Wht @ 210 220 lbs

CPC = Cutler Performance Center

Dynamo^Joe
04-26-2003, 11:31 PM
Heh, Im kindof a stickler when it comes to terms in clutching.
You have to watch when using the word "rate".
Rate is How Much Something Changes per distance or per time.

Krusty nailed this bang on.
He took the final compressed force [at full shift] and subtracted the installed force [no shift]...took that number and divided it by the distance the spring travelled.
Rate, I think is something nice to know and nice to know how to calculate, but it may not be essential. "Dont quote me on my opinion"
I do like looking at the rate lines in a spring force chart though. You can have a thought of what you need and just by looking at the lines, you can guestimate quickly what may be beneficial or not for your application.

When talking of springs, "Force" is the term I like to use all the time. The force is the number that I am worried about to resist the flyweight under acceleration.
Just like when I discussed the example earlier of the 200-x springs.
I look at the force numbers to generate a solution to problems we analyze. :D

Sorry to sound like a "correct" officer. haha....

Krusty
04-27-2003, 03:26 AM
Joe, what's your experience, if any, using notched ramps (engagement) in relation to spring "force"? Assumably, the flywieghts have overcome the engagement point of the spring, and the notches hold the arms to a given rpm. Does this have an effect on the spring? Also will it overshift on the ramp once released from the notch, having to backshift momentarily to let the engine catch up? This is 500 feet on grass. 700 improver. Thoughts?

Rocketman
04-28-2003, 02:23 AM
Originally posted by ballsout1@Apr 26 2003, 04:33 PM
Krusty, and rocketman, you meant well....
whoops....typed that one out in a hurry...my mistake :doh:

Dynamo^Joe
05-02-2003, 10:38 PM
Krusty:

Tell me only what you think you know of using notched ramps.

Is there a chance that you already know the answer to your question? ? ?

...sorry but I been Working lots of overtime and not getting home until very late in the evenings, so I really had no time to answer.

I will be back later with my detailed reply. :D

hillpounder
05-03-2003, 01:39 AM
FWIW, I've found the doo white to "act"alot like the goodwin grey. The gw blue is falls somewhere in between the beige and the white.

Dyn joe? I have one of those cat bl/wht cpc spings in my hand looking at it. Its wound bigger than the doo springs, yes? You say you use them in the roller, how about on buttons? any sign of contact anywhere because of the size difference? How much preload is typical with them? I'll throw it in my box and give it a try this weekend.

800MXZ
05-03-2003, 11:16 AM
Im a Goodwin dealer, and in case anyone wondered, the Grey 2ndary spring is no longer available, and they started to include Doo whites with their kits.

I for one am a fan of stiffer 2ndary springs also.

Mikadoo
05-03-2003, 07:52 PM
So how much secondary pressure is enough for the common high perf. sled? Why has Skidoo kept with the Beige spring like "forever"?

Dynamo^Joe
05-04-2003, 01:55 PM
Hey....

that bl/wht cpc spring, you do mean blue/wht, right?

Slightly bigger o.d. yes...fits in Dooey Roller/Button clutch...YES!
I use them in roller clutches.

Button clutches it depends on what brand of helix you use. The spring maybe you think that 30 lbs is not much more than the Beige spring, but I tell ya man, I have wore out buttons in less than 80 miles. hahaha...
Really crushes the hell outta the buttons if the roller/button path on the helix is not coated.
And really, Im not exagerating that they will wear very fast. I used SPX, HRP helix which are total coated every square inch, even roller/button path...will wear buttons out in less than 200 miles. [440 sled & Formula 583 as test mule(s)]

I used Amsoil grease, White silicon grease, Extreme pressure grease, Even that gaw damn expensive Iso Flex grease and same thing...Quick wear. As soon as belt dust, but especially salt dust [from road] gets in clutches, the buttons start to wear.
You can tell salt is on clutches by sprinkle water on parts, then run very high temp heat gun [350deg] along metal and the salt turns white leaving streaks in water smearing as the fan blows the water along surfaces.
I have a dye from my non-destructive testing work that shows corrosion chemicals like salt on aluminum materials.

Just leaving aluminum material in slightly damp area [garage/shed/back of truck under cover] for a week will show salt on aluminum deposits. Salt "Etches" aluminum almost like leaving a "Tattoo" on the surface which is hard to take off unless use a lot of elbow grease.

Using the CPC-Blu/Wht spring, Only way to prolong wear several times is to use very hard buttons like the Sno-Pro Buttons from a 96-97 mxzx 440 secondary. This secondary has the Black or Yellow buttons with a "Green dot" in the center. Very very hard, yet very expensive.
Look at this ridiculous price...$27.00/EACH[u.s.d] - Part #415064100 - KIT-SHOE CAM SLID.

But for absolute learning purposes, I would buy a bag of cheap plastic cam shoes.
Just change them every 50 miles or so.
You will find that by changing over to this CPC spring and doing nothing else than leave at 18 lbs pretension, your peak rpms will be raised a little. So if you have a peak of 7800 tach rpm, I am willing to guess from previous experience the rpms will be up 100.
***have to remember that tachs are out***

But lets just say that your rpms increased almost 200 rpm from 30mph to full speed.
You look at tach and it looks like 200 rpm...

A] What do you do to compensate for this problem?

B] Is it a problem knowing that Dooey tachs are on average 175 rpm high. [Ex, you have a 7800 engine, prior to this exercise you run 7800 on the tach and now run nearly 8000 tach rpm]

What do you think the difference in speed will be in "B" ? No need to ramble off any numbers, but would the speed be less?...more?

hoping someone will answer...

machz69
05-04-2003, 02:23 PM
dynamo.........lol.... i have to say you have my attention for the first couple of posts but now i just cant seem to bring myself to read the 2 page diary posts anymore...... is there a short version..............;).......hehehehe

Dynamo^Joe
05-04-2003, 02:34 PM
Yeh heh....I know I know. *sigh*

It is always like this I find and I cannot help myself getting deep into any one certain area.

I just find that a short answer is an uninformed answer. But I do find that is all 99% of people want. They don't want the findings behind an answer, they just want numbers and.......go!

But one person here or there questions me and has passion to go try different tactic to get what they want. I spend a lot of time pointing directions and troubleshooting.

I love to give long answers for that one person to converse with me on their thoughts...On forums, hundreds read my posts and one person[s] will contact me with what they found.
I crave information and I love it when people correct me and I can correct them on their thoughts.

........sorry, I'm a clutching NERD ! ! !

Krusty
05-04-2003, 02:54 PM
Joe; I'm not really sure I know that much about the notched ramps. I would rather not use them to be honest. I guess I did kind of answer my own question. I was looking for verification.

My motor dosen't make much torque down low, so I had to notch to get the engagement up to 6500 to 7000 rpm. The most I could get without the notch was 5800. That's with a 310# start. It wouldn't pull out of the hole cleanly.

It seemed, with the notches, it would load the motor down too quickly and pull the rpms down. It also created a traction issue. Using 280 ramps, it seemed to help when I had the clickers in 5 or 6 to "steepen" the ramp and slow down the shift somewhat. It was also tricky to get the notches on the right spot on the ramp. Just forward enough to hold the roller, without using up half of the ramp.

Now all of this information was obtained with the motor being too fat on the pilot. Too lean inthe middle. And too fat on the main. (now corrected on the Dyno) It was also geared too tall as well.

Soooo many variables. Take as much space as you need to post. I love to learn. ;)

Dynamo^Joe
05-05-2003, 10:28 PM
Hey Krusty:

Personally I have not used much in the way of notches regarding flyweights or ramps.
In the past I learned how to notch. After watching other riders operate my sled, I did not like how notches reacted at the start line. The cause/effect made me toil away learning different exercises to develop how to make this better.

...not necessarily in any order here, but the more I changed and raised engagements, the more violent some details became...the less violent some details became.
It was hard to make my sled consistent at different ice tracks.

I found that there were always:
1] Violent track spin
2] Track chatter
3] Suspension cycling in large varying amounts [Hopping several times in less than 50 feet]
4] belt wear
5] Engine rpms dropping once sled hooked up.


I changed my procedure from grinding a notch to a nicer formed curve to be much more gentler on the roller. The engagement would be higher than stock, but would smoothly engage the clutch. Kinda the same feeling like using a MAG arm.

I would say it is proper to use the term overshift for #5 in the comments I made there. Not saying this is always the case, but I seen on my sled[s] when I got track spin, the engine would for the most times overrev, then drop rpms below peak when the track hooked up.

Have to remember that the belt is like a steel band between clutches. The secondary reacts to the engine torque absolutely...instantly.

Test day:
Pick a location several feet out from a start point. For lack of better numbers say 40 ft from this start point. [yer gonna do 80 ft holeshots for the day]
Lets think of you accelerating the sled.
Test one: you pin the fuel, you spin the track, scratching the ice for several paces and then the sled hooks up.
Test two: you pin the fuel, the track barely spins for two paces and hooks very good n hard.

Looking back at test one, the actions were the sled spun, the engine revd at peak, the sled hooked, pulled the engine down to climb back up again.
Test two, the engine labored to climb to peak and stayed at peak until you let off.

When you pull the engine down like that from spinning the track in test one, it is because the TRA lever is upshifting with enough push from the engine to prevent backshift. Rpms drop/torque climbs. The secondary is getting such a strong signal that it cannot resist the push from the primary and help the engine to immediately regain peak rpm.
The center of gravity on the TRA arm is at a farther position away from the bolt center at the 40 foot mark than it would be in test one.

Torque is raising because the rpms are lowering. But remember, the rpms are lowering because the secondary cannot compensate for the primary push. The acceleration diminishes but for an instant.

Im gonna cut this boring novel off here on this part. thank god eh... lol :nervous:

Dynamo^Joe
05-05-2003, 11:22 PM
Need to find where the engine comes onto the pipe?
1]...What is the lowest rpm the engine does NOT bog at?
...heh, know how to find it?

2]...Explain..."wouldn't pull outta the hole cleanly"

My friend, there are not so many variables as you may think...There are some things that don't change regardless of what you mention of jetting.
Just have to find out what is going on here and get things in check.
Izz just step by step to configure sled...that's all. :)

Umm, there is a way to use suspension to get engine to climb to peak rpm very quickly without notch, but first other info.

hillpounder
05-06-2003, 12:06 AM
Joe,

A. add more weight (I'd try 1-2grams)
B. Slower (depends on some variables though)

Dynamo^Joe
05-06-2003, 12:35 AM
Originally posted by hillpounder@May 5 2003, 11:06 PM
Joe,

A. add more weight (I'd try 1-2grams)
B. Slower (depends on some variables though)
Yooo....

If the answer to Q1 is "A"...adding more weight to find lowest rpm engine does not bog at....

...umm, I disagree. My testing I could not load an engine hard enough with merely adding flyweight to find this rpm im looking for. ???

hillpounder
05-06-2003, 01:11 AM
Joe, sorry, I was answering about the cpc spring 200rpm theoretical. I'm staying out of the bog post, anything that needs to enagage at 7k has either too much time/area or not enough cc's IMO.

Dynamo^Joe
05-06-2003, 09:45 PM
You will find that by changing over to this CPC spring and doing nothing else than leave at 18 lbs pretension, your peak rpms will be raised a little. So if you have a peak of 7800 tach rpm, I am willing to guess from previous experience the rpms will be up 100.
***have to remember that tachs are out***
But lets just say that your rpms increased almost 200 rpm from 30mph to full speed.
You look at tach and it looks like 200 rpm...

A] What do you do to compensate for this problem?
B] Is it a problem knowing that Dooey tachs are on average 175 rpm high. [Ex, you have a 7800 engine, prior to this exercise you run 7800 on the tach and now run nearly 8000 tach rpm]

What do you think the difference in speed will be in "B" ? No need to ramble off any numbers, but would the speed be less?...more?



Ok lets ramble off The variables...he he.
Umm...my sled has a 8400 engine.
I been driving it in stock config at 8400 tach rpm while I was doing clutch testing.
After changing the secondary spring over to this new CPC Blu/Wht I did get an increase in rpm.
The rpm on the tach was at 8600 +-

When we did mph test at 8400 tach rpm I was getting 80-81 mph in 1000 feet nearly every run.
Now that the rpms on the tach were 8550-8600 rpm, leaving the clickers the same; In 1000 feet we got 82-83 mph nearly every run.

Change operators, some went faster if they were lighter in weight, some went slower if they were heavier in weight. like me with my fat ### on the sled. lol

We got a digital tach to measure calibration of the analog tach. My tach was showing 175 rpms high.
Ski-Doo tach at 8400 ~ Digital was approx 8200
Ski-Doo tach at 8600 ~ Digital was approx 8400

Our speeds were up every time we run "Tach" rpms higher than rated. I can only figure that I am now running nearly on or the closest to my power peak rpm.

Now we turned the engine a bit more. We got the engine to turn more rpms by lightening the weight to get it to run 8700-8800 Tach rpm. Speeds were down to 80 mph. No matter how many runs, I could not get the needle over 80mph.
Proof was to take apart the secondary and check the helix. I would write on it with a felt pen and the roller would just touch the line I drew. :)

Pulling flyweight out to get the engine to rev that high, the primary then could not push the secondary open enough to get back up to the speed of 82-83 mph. Not enough flyweight....not enough primary push.

hillpounder
05-07-2003, 12:17 AM
I would hope by now that most all doo tuners know the tachs may be off and try different power peaks for their testing.

Another variable I was thinking of is pipe heat, and the power peak rpm rising as it builds heat. Not such a factor on stock pipes but unshrouded custom pipes I have found this can be true. In some cases I actually have been faster coming out of the hole below peak rpm and letting the rpms build to higher torque peak at the far end of a long run. Often in short runs clutching against the torque peak can be quicker although it may not sound or feel like it? Seen the same thing clutching on the hill, make a long pull watch the mph, make a change, make another pull, lose/gain mph at the track, adjust and so on. In a lot of cases the tach error almost works out perfectly and you see you best track speed pulling the advertised rpms, which may suggest the motor/clutching will sometimes pull its hardest when loaded back onto its torque peak?

Dynamo^Joe
05-07-2003, 11:45 AM
@Hillpounder]...Another variable I was thinking of is pipe heat, and the power peak rpm rising as it builds heat. Not such a factor on stock pipes but unshrouded custom pipes I have found this can be true. In some cases I actually have been faster coming out of the hole below peak rpm and letting the rpms build to higher torque peak at the far end of a long run.

@D^Joe]...I live/eat/breath/crap 99-03 mxzx/rev 440's. Your pipe comments I know are all too true.
As an example; I find that a lot of the problem in the early sleds is the ignition.
The timing on the 99 advances too quickly in msec to let the exhaust pipe heat up enough in the short time it takes to get from low idle to high idle rpm.
Stats:
99 engine is an 8500 rpm engine with 15:1+ compression head inserts.
The 00-03's are 8400 rpm engines with 14:1+ compression head inserts.
The combination of the 15:1+ compression ratio and the ignition curve gives the tuner quite the handful to tame. This particular 99 sled of the series is succeptable to "The Zoomies" very bad. "The Zoomies = Pipe Surge" You really have to load this engine hard at lower than peak rpms to heat the pipe. I like to use the secondary for this.
I can run a 48-37 helix in the secondary and have the zoomies.
I can run a 54-37 helix in the secondary and Not have the zoomies.
The 48-37 does not let the engine labor enough coming out of the hole and thru the bottom of the midrange so the exh pipe does not get optimum temperature. I have added flyweight to try to compensate this condition and it does not work until you are on the return lane. For some reason after you are done the test run, then get the sled down low rpms to turn it around, you then give it fuel on the return, no zoomies. You hammer down and the basturd hauls at peak rpms.
The 54-37 helix loads the engine considerable more. Loads the engine hard enough that it comes off the line below the peak power, then rpms climb slowly. Zoomies are gone because the engine spent more time in msec at lower rpms. The engine at this lower rpm kept the ignition in a less advanced position letting the flame stay in the pipe longer. Flame longer duration in pipe...pipe gets hotter, quicker.

Lets imagine some fake temperature numbers here for lack of proper numbers.
Lets say that with the 48-37 helix the "pipe" temp would be 500 degrees at 15 feet from the start line.
From knowing the cause/effect of the 53-47 helix, the "Pipe" temp would be 650 degrees at 15 feet from the start line.

@Hillpounder]...Often in short runs clutching against the torque peak can be quicker although it may not sound or feel like it?

@D^Joe]...You don't have to question this, I find it's true. I do like to skin the cat another way though. I like to make the engine labor thru suspension action to come off the line. The engine labors to peak rpm. I have been able to do this with newer models of mxzx/rev 440. So my personal sled does get clutched to 8400 rpm to drag, not at 8200 rpm like most people I know who drag these sleds. I use more flyweight and wide spread angle helix's.
I been trying this path just to learn more clutching. :)

Krusty
05-08-2003, 12:57 AM
Thanks for the info guys. I haven't got a lot of testing on this combination yet. (700 triple from a 670) I have tried light pin/light spring and heavy pin/heavy spring combo's as well as mags arms. Decent results but the sixty foots need to drop two tenth's. Have it geared down from a 2.20:1 to a 2.42:1 to help it "flash" out of the hole. Of course this new gearing with a 6800 rpm "in" won't help my traction issue.

As you descibed, it would break traction, over-rev, pull the motor down, hook up and then try to re-gain rpm. Or, as in your other example, hook well but struggle to reach peak rpm.

I'm interested in your suspension compensation. That's a new one to me. I've considered removing some studs to try to get a consistent "spin" out of the hole.

Dynamo^Joe
05-08-2003, 12:37 PM
Personally I don't care for mag arms, but I do not know if they would be beneficial on a 3 banger.
I hear so much "here-say" some guys like them...some guys not. Damn but there is a few ways to skin a cat eyy...

Im just talking of me here, I will not use mag arms again in anything if I can help it. I like heavy arms for the benefits from my learning. I would even like to m/c my own heavier arms to use lighter pin weight but maintain heavy overall arm weight. This will happen in the future for me.

First off I find where the engine makes power at down low. I like to find what the lowest rpm the engine will NOT bog at. I perform an exersize to find it and get a friend(s) to help out and let them perform the procedure too. We keep the noted rpms to ourselves after making 4 or 5, 60 ft passes, then compare notes on what rpm we found. Playback tach works pretty good, but if you don't have one then taking an average of the numbers you record will be most beneficial anyway.
Joe makes passes and finds 4700, 4800, 4700 rpm where engine comes to life.
Larry makes passes and finds 4700, 4700, 4800 rpm where engine comes to life..
Curly makes passes and notes 4600, 4700, 4700 rpm where engine comes to life...

We should be safe to say that 4600 the engine comes out of the bog and about 4700 is where the engine wants to snap to life.

Once the procedure is done and the low rpm is found where the engine comes on the pipe, this is where I get into the suspension to wake the sled up.
For testing purposes Im leaving the engine engage at 4700. If higher is needed, then so-be-it, but for now testing will be done there. Raising rpms can be done easily after.

I have to say though, from my experience the best way to get the suspension to work is to have the capacity to do shock re-valving. Man you can really make an engine "wham" to peak from making use of the suspension. At least this has been done from the engines I worked on.
I will admit I have only ever really worked with one 3-cyl engine.
...regardless, the procedure to "find the pipe" is the same for any engine.

Considering removing studs to get a consistant spin... I disagree. I want the complete rail on the ground and no spin at all. I will work with the suspension to make it the best I can to work like that.
I don't want catwalk, I want chassis transfer.
When you make the sled hook up with rails flat on the ground neglecting talking about the action of transfer, the secondary will make less turns to the 12' mark from the start line. If you spin, then how many turns will the secondary make to the 12' mark? I dont know, but it will me more turns.
When you spin the secondary less, the engine will have a harder time to pull the belt. The primary will have a harder time to push the secondary open. You are still on the fuel here, so what is the engine gonna do while the suspsension is keeping the primary and secondary in the lowest ratio? The engine will climb to its peak very quick.

...whuhh...this is a deep subject which I could write a novel just for what happens in 12 feet. lol

I cut short here to say that planning is a key to success. Troubleshoot each issue that pops up and read the notes you made.
Im telling you that if you write notes on what you did in your exersizes you will learn in leaps and bounds. When you have a question, you will ask the write question but more importantly you will know how to ask it because your notes told you how to do it.

...no notes? ???
...no info ! :(
...no learn ! ! :sleeping:

u can email me for finding pipe there Krusty.

Krusty
05-08-2003, 02:39 PM
So if I understand it correctly, you need to have as close to complete traction as you can. This allows the clutches to mantain a low ratio while also allowing the secondary to handle the torque more efficiantly. If the track is spinning, then it allows the secodary to open and the primary to start to shift. I guess this would cause a drop in rpm also as you found traction, again, necessitating a momentary backshift. I won't be testing till mid June, but the more info I have the better off I'll be.

Do you prefer a heavy arm/ heavy spring set up?

Dynamo^Joe
05-08-2003, 04:33 PM
KRUSTY]...So if I understand it correctly, you need to have as close to complete traction as you can. This allows the clutches to mantain a low ratio while also allowing the secondary to handle the torque more efficiantly. If the track is spinning, then it allows the secodary to open and the primary to start to shift.

JOE]...Well, that's my thoughts on the matter.

KRUSTY]...I guess this would cause a drop in rpm also as you found traction,

JOE]..Yep. RPM drops, torque rises to a point of its highest level, secondary feels this signal....

KRUSTY]...again, necessitating a momentary backshift.

JOE]......and compensates for engine torque hitting it's peak, then lets engine climb to peak rpms again by resisting the push from the primary. "Backshift"

So thinking here, if we are accelerating the sled as hard as we can, then some event happens during this several 10ths of a second to get to 60'; The word "backshift" pops up into the conversation, then im guessing if there is backshift, the sled is not accelerating as hard as it can to its max potential.
What kind of improvements would be there if you only spun the least possible amount. Spinning is the variables that I want to leave out of the picture. Its too hard to clutch this variable with different track conditions.

JOE]...You have rear shocks with the capacity to have the valve stack changed?

KRUSTY]...Do you prefer a heavy arm/

I like the benefits of a heavy arm. The capacity for strong backshift signal in my opinion is substantially quicker than the mag arms from all the exercises i've done. I don't like revvy clutching that the mag arms provide in many cases. The heavy arms I find use more of the meat of the torque curve in an engine. The primary pushes harder at low rpms so you can make a small cc engine feel like a larger cc engine when moving around thru low end midrange speeds. I like the way a heavy arm works well with large spread of angle helix's. Can really make stuff haul freakin-a$$ in the midrange.

I have limited my knowledge with mag arms. I never really give them a chance and now after some experiences in other areas, Im sure I could get some good results, but for the price of them...BAH!
Me rikey cheepy cheepy stuff. hee hee hee...

KRUSTY].../ heavy spring set up?

JOE]...I never know which spring I have to use. After a bunch of testing I can make a good guestimate of what direction to go next.

:)

800MXZ
05-08-2003, 07:45 PM
Joe - I myself am having a hard time distinguishing in the thread what is info and what are questions you have left for others to answer.

I for one want to get in on this, but I am having a hard time straitening it out.

800MXZ
05-08-2003, 07:57 PM
I would like to know where the Doo white 2ndary apring falls into all of this. There has been allot of comparison of the beige to this CPC B/W but what about the Doo W? It is one heavy duty spring (stock on the Non RER 800s) and is what I have found to be best for the 800s.

I for one am not hooking a sled with pics on ice. Im running 1.25 paddle on hard pack and or loose snow.

I have found this to be the best accelerating setup for what I have done

240/320 primary
280s
21.7grams (with my engine config)

Doo white
Strait 47 or strait 50
A6 (21lbs)

But not matter where I set the alignment, or helix, everything runs damn hot. I mean, belt life is rediculus.

Would you consider my shallow cam to be the cause? I for one would think a shallow angle will grab the belt more.

But I have run softer primary with less weight and it seems worse. I have tried all the trendy stuff and just never get the results.

This setup and my sled (2001 MXZ800) and it pulls great and runs good. Heck I have pulled up on the snow banks on the ice track on my lake and can beat anythig out of the hole with trail studs. I just can not fogure out for the life of me why my belt life is so bad. I have found the U2 lasts much longer and is fine for trail riding, but for serious running I use a 067 doo.

800MXZ
05-08-2003, 08:03 PM
I have used the specs in the Race manual and a alignment tool for alignment, but have thought that the belt bottoms in the 2ndary clutch.

Seems like I have never got full shift on the primary.

Dynamo^Joe
05-08-2003, 09:49 PM
Joe - I myself am having a hard time distinguishing in the thread what is info and what are questions you have left for others to answer.

I for one want to get in on this, but I am having a hard time straitening it out.


800mxz, Its all information. I think just for you wording your comments like you did, you prolly know more than you think you know.

Sorry for my poor delivery. What i've been spewing is just recollection of notes I make in the field and review when im sitting on the sh!tter.

Im trying to say things without me looking like im spelling things out as a know-it-all. I don't really know anything other than my notes and try to be well versed in theory.

The way im coming across is to try to raise questions, from anyone.

its like when I read Aaen or Cutler clutch books, I don't really find any answers. Good theory and some technical advice, but there is no data in any of the books. If anything the knowledge on the pages makes me raise more questions for myself. Questions on how to solve problems I encountered.

I just like to convey as a conversation hoping I get constructive thoughs, but morely I like to read other peoples experiences.

This kind of talk is wheels within wheels... :thumbsup:

So just say what you know, and say what you thing you know. :D

800MXZ
05-08-2003, 09:57 PM
Ok, in my mind, less helix would translate to more side force on the belt. Since we have less "wedge" between the shieves. I just have wondered if I should try more cam to keep the belt out of the bottom of the 2ndary.

I tried the beige in this sled, never did like it. Also a EPI red (same damn spring IMO)

I have considered going to a Cat 2ndary for no other fact than it has a smaller finish diamater and will allow me to shift out on the primary. (A Team clutch is also along the same idea, and wouldnt require a special jackshaft)

Dynamo^Joe
05-08-2003, 10:51 PM
800mxz]...I would like to know where the Doo white 2ndary apring falls into all of this. There has been allot of comparison of the beige to this CPC B/W but what about the Doo W? It is one heavy duty spring (stock on the Non RER 800s) and is what I have found to be best for the 800s.

JOE]...Yep, I agree it is one heavy duty spring. Im gonna compare the GW/Blue to the CPC spring.
CPC - Blu/Wht @ 130 lbs
GWin - Blue @ 135 lbs
I just took the values at full compression less .040"

For lack of better clutch details lets use this.
Straight 47
GW-Blue
A6 (21lbs)
Ok so at rest when you do a pretension test, you pull about 21lbs.* Now take the scale and keep pulling the secondary open until you cannot pull it no more.* The tension on the scale reads 29 lbs.
========================
Straight 47
CPC B/W
A6 (21 lbs)
Ok so at rest when you do a pretension test, you pull about 21 lbs also.* Now take the scale and keep pulling the secondary open until you cannot pull it no more.* The tension on the scale reads 34 lbs.

At full degrees open the difference is 5 lbs. Might not sound like much, but this could be a substantial number when wanting to "maintain" top end, especially when the snow starts to get deeper, or there are bumps...basically keeping speeds when the clutch loading gets more severe.

This is one thing I like of the CPC spring over the beige spring. If you wanted to do a calculation after measuring the springs you would find the spring "rate" on the CPC is much higher.

I know that pretension wins races, whether it be ovals or drags or fast trail riding.

Here is more comments of the effects of not only the cam angle that comes into play, but its path length.
The path being what the button or roller rides on the helix.
http://www.picturetrail.com/gallery/view?&...id=17807801#top (http://www.picturetrail.com/gallery/view?&p=3&uid=486172&gid=1520953&&imgid=17807801#top)
This is from my incomplete online manual for my clutch kits I sell. Not really need to know stuff, but guys like to read this stuff.

800MXZ]...I for one am not hooking a sled with pics on ice. Im running 1.25 paddle on hard pack and or loose snow.
I have found this to be the best accelerating setup for what I have done
240/320 primary...etc etc
But not matter where I set the alignment, or helix, everything runs damn hot. I mean, belt life is rediculus.
Would you consider my shallow cam to be the cause? I for one would think a shallow angle will grab the belt more.

Hmm, surprised at how much flyweight you push. But I guess looking at that you run 280's they are a thick ramp which hold the flyweight tucked in more compared to a stock ramp. So then you would need to run more weight.
I define shallow cam as lower angles. Angles less than 45 degrees. I define large angles as angles more than 45 degrees. Me having this definition is a pure geometry thing.

High or Hot clutch temperatures are from belt slippage. The friction is low. HP going up in heat. Think if you could harness this heat and put it to the ground. How much HP to the ground do we lose because of heat on the sheaves. Im willing to say that a lot of it is from the helix. The amount the secondary sliding sheave rotates in degrees is very coarse. Ever try a 53/37 smooth progressive? Many people are just agasp when they see numbers like that. But don't knock anything until you try it.

800MXZ]...I just can not fogure out for the life of me why my belt life is so bad. I have found the U2 lasts much longer and is fine for trail riding, but for serious running I use a 067 doo.

JOE]...Slippery belt/sheave contact. How can you get the sheaves to grip the belt better? You already have a huge spring like you say. Is this enough?

800MXZ]...Seems like I have never got full shift on the primary.

JOE]...I think a more accurate picture of your condition will be from checking the path on the helix. Look at the mark on the helix. How far does it go down the path. Put your helix on a table and measure with a tape from the top of the helix and measure down VERTICALLY. On any Dooey helix you need to go 1-1/16" [28mm] vertical down to get 1:1.
Measure from the top of the helix down to 28mm and then run your finger in a straight line towards the left to meet the angle of the helix. Does the black marks meet your fingernail? Is the mark above or below your fingernail?
If your black mark is not 28mm down then you are not at 1:1.
If you are not at that point then you need to do some more belt squeezing. You already have a mondo spring. Mebbe you should start to come down in the helix number.
Remember that your secondary sheave only opens towards the chassis by 1-9/32" [32mm]

800MXZ]...I tried the beige in this sled, never did like it. Also a EPI red (same damn spring IMO)

JOE]...It is. I bottomed the red spring right to .040" less than coil bind and it was not even 5 lbs more in force than a beige. BAH!!! Hate when companies do that. Nobody will be happy until ur broke.

800MXZ]...I have considered going to a Cat 2ndary for no other fact than it has a smaller finish diamater and will allow me to shift out on the primary. (A Team clutch is also along the same idea, and wouldnt require a special jackshaft)


JOE]...NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOO ! ! ! ! :nervous: Don't waste your hard earned $$$.
Yeh, personally I endorse the ACat secondary and the Team roller. I would not recommend any other, especially the MHO other JUNK aftermarket secondaries like a Sh!tter torkker or other ilk. GAD! ! !
Yep the AC roller is a beauty clutch. I love them. Helix's are cheepy cheepy and every single secondary spring on the market fits this clutch.
Team roller...Yep, I like this too. Helixs arent too bad of a price. Nice features of two helix in one. Good selection of secondary spring. Good roller design....blah blah blah. Great secondary MHO.

...But I would stick with Bomber because it is prolly just a matter of a helix change if you have a button secondary. If you have a roller bomber then a helix and secondary spring change.
Next season, I could sell you a helix I gurantee will lower your temps. And as with what I sell I offer money back gurantee. But I calibrated the non rer helix for roller secondaries and ur stock tra ramps. If you have roller, great. If not, then I could recommend a helix that is close which you buy from bomber.

800MXZ
05-08-2003, 11:22 PM
Well, I have tried a 48/40 Coated Goodwin (I had it laying around for my Mach).

Using this cam it just doesnt pull. Seat of the pants, in the good weather. I have spent considerable time wrunning with sleds set up very similarly (RK Tech head, shim, V force) and they are all running similar setups.

I like the 280s just cause it allwed me to run that stiff spring, which I like with all that "rate". Makes for a very fun sled to ride in the trail. Cal me an idiot, but I like to throw in about 20 grams of weight, pick my ramps, then tune via spring.

800MXZ
05-09-2003, 12:18 AM
DJ - WAY back in the thread we talked about strait vs compound angles.

See, Im running the strait 50 and 47, but that is similar in force half way up the can I bet from the severe compound angles you use. Not exact, but similar. I looked at your pic of the comparison of the 53/36 and the strait 46 and 36. Overlay the 3 and youll see the "dip" that happens in the middle of the compound helix.

Just my way of looking at it

john breedon
05-10-2003, 01:07 PM
the best way i have found of explaining the difference in helix angles and resultant pressure is to think of the helix like a bolt,the coarser the thread the steeper the angle,less of a pull by the belt results in more distance traveled up the helix,there fore quicker opening,which will result in more load on the motor ,which should lower the rpm.If it doesnt lower your rpm then your primary is loaded too light and you have not been transfering alll the power you should.I too have changed back to a less steep helix without raising my rpm,but it felt revier and did not et or mph as well as the bigger helix.tune primary first then load up the helix/

baddude
05-11-2003, 04:45 PM
By any chance does anyone know if CPC has a website?If so thanks.
Baddude :D

800MXZ
05-11-2003, 05:14 PM
Cutler (http://www.cpcracing.com)

baddude
05-11-2003, 08:14 PM
Thanks,mxz800 :D

doo900
05-11-2003, 09:44 PM
all this clutching talk makes me wonder and think to hard ,it drives me crazy. i got a theory i'll throw at you . last year at the asphalt drags 660, i run a 900 crank shop twin with a 230-410 280's, 21pins,54helix, beige spring @18 lbs , 24-38 gears everyone said no way , but that is what i ran and did a 6.22@106 mph w/ a 60 ft of 1.36 . well this year i gave other ideas of less helix, higher gears and different ramps , but i can not get it down to last years times . i had belt slip (no doubt) but she flew

Dynamo^Joe
05-13-2003, 09:40 AM
MXZ800]...Well, I have tried a 48/40 Coated Goodwin (I had it laying around for my Mach).
Using this cam it just doesnt pull. Seat of the pants, in the good weather. I have spent considerable time running with sleds set up very similarly (RK Tech head, shim, V force) and they are all running similar setups.

JOE]...From what I gather, I have to wonder if the start angle needs to be larger to get the exh pipe hotter/quicker when you pour on the fuel. Stock engines/ignitions, the timing might advance too quickly and move the heat into the chamber when it could have stayed in the pipe for a bit longer in 10ths of a second. This could be happen especially if compression is up over 135-140 lbs. I believe for that to work you could load the engine harder with a larger angle and add flyweight to keep rpms in check to compensate for the helix dropping in angle like that. But, I still think that 40 is not low enough for a finish angle. :)

MXZ800]...I like the 280s just cause it allwed me to run that stiff spring, which I like with all that "rate". Makes for a very fun sled to ride in the trail.

JOE]...Thick ramps have a lot of "fun factor" I liked the 280 ramp. Used to take out the 283 or 286's out of any mxz/formula with a 583 engine and replace them with a 280. Guys mentioned they like the snap in a twisty trail.

MXZ800]...Call me an idiot, but I like to throw in about 20 grams of weight, pick my ramps, then tune via spring.

JOE]...Hmm...Its all in the way you troubleshoot problems. Regardless of how you choose to change details, the analysis directs you on what detail you must change to compensate for the symptom.

MXZ800]...DJ - WAY back in the thread we talked about strait vs compound angles.
See, Im running the strait 50 and 47, but that is similar in force half way up the can I bet from the severe compound angles you use.

JOE]...Heh, "severe", "extreme" "extravagant"...yep, people say to me these words of such ilk when they hear the spread[s] of helix I like to recommend.
People think that I exceed reasonable limits but I always get silence when I ask them "what is reasonable?". LOL

MXZ800]...Not exact, but similar. I looked at your pic of the comparison of the 53/36 and the strait 46 and 36. Overlay the 3 and youll see the "dip" that happens in the middle of the compound helix.

JOE]...I believe that this dip you see is the angles that are larger than 45. When you look at the layout on a sheet of paper as such, the "dip" gives the viewer an illusion of it being 1/2 way down. But really it is not. The dip is only about 1/3 down the vertical height of the helix.

As far as the force you mention being the same, lets say with the 47, I agree there would be the same force under acceleration, the 50-36 would only quantify the same force as a straight 47 for an instant of about 7mph as the roller or button travels down the helix path. There would be only one particular point on the 50-36 helix that would exhibit the character of a 47. This would be due to pure helix angle in action, neglecting a spring value thrown in.

hillpounder
05-13-2003, 11:35 PM
food for thought: A straight cam like a 47 or 50 is progressive as far as the force the roller or buttons "see". As the belt shifts down the sheave it has less leverage on the cam (or vice versa).

Dynamo^Joe
05-14-2003, 02:42 PM
Great point...

...you empower my faculty of reason so as to arrive at conclusions of the benefit[s] using multi angle helixs.

Need the helix angle to drop to gain a good steady grip on the belt.....pushing the sheaves against the belt as the rotation increases.

I really think they have absolute benefit to "sustain" the highest speed possible. Not just go to the highest speed and then drop off once there is a load change, but to sustain as hard as possible in difficult clutching loads.

When I was over at Team ACat doing clutching for a factory racer, we got the little 440 to run 104 to 106 mph for a 35 minutes straight with no letting off. This was with a 1" track, pickd.
Sometimes we used a helix like a 60-40 progressive.
We found a helix angle "needed" for the speed the sled was going at. It had enough balls on bottom to pull the 60, but remember that it only stays in 60 for about 5mph under full acceleration and the helix angle starts to drop quickly as speed increases.

:)

hillpounder
05-14-2003, 09:53 PM
Joe, riddle me this one: I played with 2 cams this year on my mod and stock 700, 46/36 and 50/40. Never could get them to pull as hard clear through the shift like I could with my 47 or 50? Also what's your thoughts on lightweight arms? I played with some mags and couldn't get them to load as hard as I wanted down low. Would liked to have tried them with a multi bigger multi.

800MXZ
05-14-2003, 10:17 PM
I for one have seen many with sucess using 60/50 60/52 on the 800 twin also.

I know on a buddies ZR600 he runs a 60/40 and this thing hauls the mail upstairs

Krusty
05-15-2003, 02:31 AM
Hillpounder; for what it's worth, I found the best combo for mags was huge pin wieght and a stupid soft spring. Ran 22 grams and a 150-240 spring on a 670. Holeshot like 90 but a little soft upstairs. Good corner to corner set up.

Dynamo^Joe
05-15-2003, 09:28 AM
HILLPOUNDER]...Joe, riddle me this one: I played with 2 cams this year on my mod and stock 700, 46/36 and 50/40. Never could get them to pull as hard clear through the shift like I could with my 47 or 50?

Would have been interesting if you had some temperature data to go along with your findings.
Do separate temperature tests with each helix you used. Perform each exersize the same with each helix.
What if you did a trial run where you put the sled thru its paces, stopped and then measured your secondary temperature?
Ever burn your hand? How many seconds can you hold your hand on the sheave faces of the secondary before taking it off?
In addition to your seat-o'-the-pants comments, the temperatures you measure would have raised more questions for yourself because of a key relationship between temperatures vs efficiency.

I'm sure you have good recollection of the information you gathered.
So what went on here with your exersizes; When you tested, were rpms higher?...lower?
How did the sled respond to your throttle position when you got on and off the fuel?...snappy?...sluggish?
What was your top speed like between helix's?

HILLPOUNDER]...Also what's your thoughts on lightweight arms? I played with some mags and couldn't get them to load as hard as I wanted down low. Would liked to have tried them with a multi bigger multi.

The center of gravity on a Mag arm is closer to the clutch bolt/shaft center compared to a heavier aluminum arm. Using the mag arm, the engine has to produce more rpm to force the pressure lever out from low shift positions on the primary. You have to "jazz" the throttle more to get the sled to move or jump. Visually, you see lotsa rpms with little sled movement on the bottom end of midrange.
The mag arms use less of the "meat" of the torque curve to supply upshift signal.
Regardless of how big of angle on the start of the helix....a revvy primary is a revvy primary.

There is a way to tame the throttle responce though. People get by and do fairly well with Medium or Heavy adj pins to taylor the flyweight for the application and common use is primary springs in the range of say [130/200] to [160/270]
Very light spring in the start of the shift to compensate for the "revvy" [Gets the revvy out]

But from what I played with MAG arms, I found they were difficult for me to get great backshift responce at high speeds. One exersize, I would go flying down a steep hill at about 60+mph @ peak rpms, then let off the fuel a little to go thru the bottom of the hill, then up the other side, I found that the engine would hang up to 400 rpms low and labor hard, the mph would not increase, I would just labor up a hill maintaining the speed to which I let off the fuel at. I played around to spring up the primary, I played with lower angle helix's...
I got annoyed very quickly and went back to heavy arms. Perform the same test, and rocket up the same hill at peak rpms. I did give the arms a fair chance and did play with them quite a bit, but got frustrated many times.
I look back now and I think I could now do better with them, and lets say I could do better to compare evenly with what I use for heavy arms...Well if I could get them to run as good as heavy arms, then I would be out moocho dinero $$$. Me not getting back to play with them I admit I am limiting myself, but im not interested in toiling away with it.
Im way too involved with learning to make the most bone stock sled components work their best.

Krusty
05-15-2003, 11:41 AM
Joe; the 670 mag setup was my trail sled 95 Mach 1. Mostly used a 48-40 helix and geared down to 24-44. Was a rocket in the trails,excellent backshift and went through the gun at 108. Not bad for an antique sled and a 280 pound rider. Cool clutches and long belt life.


To another subject. This would apply to all sledders trying to dial in clutching.

Say you want to focus on the primary first and then experiment with the helix. Is it plausable to run a straight cam, get the front where you want it and then start playing with compound cams? What is the cause and effect on the primary.

Example. Lets say I'm revving at 8000, all the way up, nice and flat, with a 47 degree. Now I switch to a 53-47. What happens to the primary? Lose revs on the bottom? Top? Unchanged?

These are just numbers fro arguement sake. No particular sled. I hope you can understand my question. Trying to take the compound variable out of the equation.

Dynamo^Joe
05-15-2003, 11:57 AM
Sorry, I had Krusty name in Hillpounder place, by mistake... :0:

was supposed to be Hillpounder. :sleeping:

I fixed.... :D

Dynamo^Joe
05-15-2003, 10:44 PM
To another subject. This would apply to all sledders trying to dial in clutching.

Krusty]...Say you want to focus on the primary first and then experiment with the helix. Is it plausable to run a straight cam, get the front where you want it and then start playing with compound cams?

Yes, this is exactly what I did when I built my 440 mxzx/rev clutch kit I sell. I started with a 48 helix.
Thru measuring temperatures, I was disapointed with the overall performance of the sled and top end. I chose one of several springs to try to get the temps down.
With this spring changed I found yes the temps come down but my rpms were up.
I compensate for the increased rpm and added flyweight to bring the rpms back down.
I did runs across a 2 mile long lake. First drag race in 1/4 mile, then keep going down the lake and record data.
Because i added more flyweight my rpms ended up falling off peak and I would go several hundred rpms below.
I compensated with a 47-41 helix.
I could sustain the rpms for hundreds of feet farther.
I kept losing rpms at top end.
I compensated again with a 47-37 helix and went hundreds of feet farther than the /41 and had higher mph.

I started with my mxzx 440 doing 79-81 mph. In one weekend I got 2/3rds done my clutch kit and had the sled going 88-89 mph. Increased midrange acceleration bigtime. I mean I f-king cream stock 440 mxzx's baaaaaaaaad. hahaha...You would shiit.

Krusty]...What is the cause and effect on the primary.
Example. Lets say I'm revving at 8000, all the way up, nice and flat, with a 47 degree. Now I switch to a 53-47. What happens to the primary? Lose revs on the bottom? Top? Unchanged?

Have to remember one thing that you mention to finish with a 47. The Helix starts at 53 and actually finishes at 48.
or you could say it this way...
The helix starts at 53 and finishes at the very start of 47 degrees.
If you want a helix that finishes at 47, then you would want a 53/46.
The helix starts at 53 and finishes at the very start of 46 degrees. So your button would actually get to use a portion of the helix in 47 deg.
im going to ask Dale @ Dalton to confirm this

So what happens to the primary is nothing. You have certain amount of flyweight installed, the primary pushes with "X" amount of force and that's about it. More flyweight, more force. Less flyweight, less force.

If you lose rpms on the bottom, it "should" be because the secondary cannot resist and compensate for the push coming from the primary. Will the engine lose rpms?...who knows. My experience is that if there is a mother of a secondary spring in the secondary that can really apply the clamp on the belt while under acceleration, then yes, i have seen lower than peak rpms. Secondary temp test is cool to touch. Probably the most popular result is seen, the engine hits peak coming out of the box, track spins, sled speed increases, then track hooks up and rpm is lost, then rpms climb back up.
Say for my 440, I have played with helix as large as 56 start angle. With the beige spring, I have kept peak rpms coming outta the box because my traction was very good. Temperature measurement on secondary was higher than when measured with lower angle helix. I would think then the reason at that time I did not lose rpm was because of slippage in the secondary. Pin fuel...engine flashes to peak, temperature rises...
...I am convinced loss of acceleration went up in heat but let engine keep peak rpms.
...NOW with the big secondary spring I had installed, it really put the clamp on the belt. Whuhh...could I make that engine bog now...Pull down right to 7900-8000 rpms, then climb.

Not sure if I can answer your question, but all I feel I can do right for you here is to convey my experiences with what you mention. As a matter of fact, I have used the exact helix's you mention.


I could start a new topic with the exersizes I did with friends to build my S4X clutch kit.
It is long winded, but the data is factual and I explain in very understandable detail of the process of how I got 10mph increase and more midrange that I care to elaborate on.
I give real numbers of helix I use and radar'd mph's.
Even novice tuners can see the relationships of the data recorded to the results we got.
Two years ago on the AMSNOW forum, I posted this 4 day weekend of pure clutch tuning. I called it "Clutching Weekend" Pt i, ii, iii, iv.
...but only if you like to read clutching notes.
Since that weekend two years ago, I have got my sled 14 mph faster with pass after pass of stock clutching.
I can install my stock clutching and get 79-81 mph on the same lake. I put my kit in and I get 92-93mph, pass after pass on radar.

:inlove: This is what I sell today to others with 440 sleds. :inlove:

Krusty
05-20-2003, 01:17 PM
Joe can you E mail me a copy of that info. I would love to read it.

Dynamo^Joe
05-20-2003, 08:36 PM
:D

This is something I did with the help of many friends back in NewYear's 2002.
This was the beginning of the S4X clutch kit I flog that many people use in their 440 mxzx/rev's today.
Its a 4 part story with all the details from notes that I wrote all weekend long back in 02.

The CLUTCHING WEEKEND....Pt 1
Dynamo^Joe on 1/2/2002 6:35:00 AM

A weekend like this does not come around often. This is the perfect thing to do for people who have the luck to have the snow, a lake to test on and "the icing on the cake" being the Accommodations to stay at the lake when there is no snow on the trail.
You probably wouldn''t catch any of us doing this during mid season or once the snow is deep enough on the trail to start putting some miles on.

Anyhoo the weekend was a success. Last year, [2000] Rocket Man''s sled [98xcr] and mine [2Kzx] were running real good. Great acceleration, not bad top end. There was hardly a 6 or 700 that could keep up to 60 mph. The only sled our whole group had a hard time to beat which rarely happened was our pal "Shooter" 2Kzx-440. For some reason that sled could get us out of the hole, pull like a ba$tard in the midrange and we could match his top end.
I mean, I traded clutches with him last year and STILL he could take my sled. Damn frustrating.
Rotaxman come up with the only thing we can think of. Shooters sled is a "Wednesday" sled with a real tight engine.
Our goal for the weekend was to beat that sled, or at least match it.

Results...Rocket and I SLAY Shooter's sled now. I mean CREAM IT!
I cannot believe the holeshot my sled has now and the midrange is so strong to 70mph. Heh, Shooter would get the holeshot because he had better hook up and then pull right across in front of me. But when I hooked up...no contest.
Rocket can start to reel me in once we get out there about 3/4 km [1/2 mile] and his sled is about 2mph faster than mine on top, passing me about the 1km mark.
Right now Rocketman has the fastest sled out of us with him around 91mph with me at 89. "This is average of 6 runs"

SATURDAY:
No radar runs today. This is the "Shakedown" day.
Rocketman and Rehab with 2001 Pro-x 440 and myself with the 2Kzx 440. Our sleds did not have any real setup in them other than stock.
Rocket is playing with the Thundershift and Rehab is playing with a weight that looks similar to a HeavyHitter. This weight has a Single setscrew passage thru the weight where you can change the c of g by moving the placement of a screw. Interesting...
Saturday is the day to pack a track, drive the sleds, Do some JETTING, make notes, [Create A Strategy] and have a direction for the serious day on Sunday.
While packing the track basically we were doing the Jetting. Hold it wide open for 3/10 of a mile, shut down and check the piston wash.
Rocket and my sled were about right on. Both of us could prolly have gone down a size or two, but this was sufficient. Rehab''s pistons showed nearly no wash. Each piston showed a glimpse of wash on one intake port.
Yeh heh, Rehab was jetted lean that day. I would not change it. It seemed to run good in a 1/2 mile WOT.

All of us were getting on our speedos from 77 to 81 mph on the lake. I could not muster up anything over 80 if I was lucky. We also a used Sportchek Radar Box.

Rehab had nothing but problems with a cyl flooding it seemed this day. He tore the carbs down several times to check everything possible to see why it would load up at less than 20mph. WOT, no problem. He could run it.
What was up?...Pilot trouble?...Bad CDI box? *Ugh*
We felt pretty bad for him for that sum-beotch of a problem.

Rocket basically moved the composites around on his Thundershift to see what kind of pattern he was gonna get.
Rehab and Rocket also tried to find the right weight in grams to run. I believe around less than 55g was chosen.
Both sleds seemed to run at a little different rpm.
The pattern the Pro-X guys was to try to achieve 8300 to 8400 Flash right off the bat, then have the engine slowly grunt 100 rpm climbing to 8500 by the large end of the midrange. This is the character of shift they wanted.

Myself, I immediately stuffed a brand new Dalton 47-41 cam in with a CPC-Green/White secondary spring set at 16 lbs.
Ski-Doo - Beige @ 115-120 lbs
CPC - Grn/wht @ 125-130 lbs
CPC - Blu/Wht @ 130-135 lbs

Primary clutch = Stock trim.
I would run out and around about 8700+ rpm.
I played with the pretension going from a range of 14lbs to 19 lbs. At 14 lbs my engine would pull down way out there, right down to 83-8200 rpm. At 19 lbs, I would pull fairly straight to 8700 and then about 70mph, increase rpms to 8800+ rpm.
So I did not want the engine to fall off or climb. Seems that 17 lbs was almost perfect at 8700 rpm and near the 70+mph would just start to climb, but not to 8800.
I chose another spring to test that I seem to like. A CPC Blue/White that is a new spring CPC manufactures. Installing that spring I played with the pretensions to find a straight shift. The thing being with this spring, I got a straight shift of around 87-8800+ rpm.
This is still cool. To me one of the hardest things to do on the SHAKEDOWN day is when playing with something new..."Get A Straight Shift." Proper running rpm can come later. he he


[b]So this day we accomplished:
1] JETTING. We got the Piston wash checked for the cold day and it seemed fine. We could run WOT for 1.5 miles and shut down to check wash. BEAUTY. Yeah we could go a tad leaner, but "safety first".
2] SHIFT PATTERN. Rocket got the kind of curve he was looking for. Something to play with and stay around. He chose a few cams to try out and found two springs that when changed made significant effects to his system.
Myself, I got the MXZX to pull fairly straight all the way to top end while yet over-revving, but straight rpms.

We both found the honey spot of pretension that worked the best for the day, even knowing that they may change due to other spring/cam setups later on.
This is the standard we can fall back on all the time.

Back in the Cottage Rehab, Rocketman and I sat around for a beer and wrote down what we're gonna do in the A.M.

Problems:
2000 mxzx is over-revving 87-8800 rpms.
Nice engine flash. Shifts fairly straight yet you can run it right off 8800.

Sunday's Plan/Solution:
1] Add weight in Primary arms?
2] Change Primary Spring to lower finishing force in lbs?
3] Lower Cam number from 47-41 to 48-44 to bring engine rpms back down?

Light the BBQ boiz; I'll go stoke the Sauna. Get the Tequila out.

Sunday Day 2 will be continued

Ps….Heh, I called Dale Toole at Dalton to make a cam for me. I know what the engine is doing way out there. There is no reason I cannot have that two mph that Rocketman has. There is no reason why I cannot be two mph faster than him either.

Grover
05-21-2003, 09:08 PM
Can anyone elaborate on ramp profiles vs helix angles? -Grover

Dynamo^Joe
05-21-2003, 09:46 PM
profile vs angle?
...umm, what are your thoughts? Point out a specific detail between the two that you are curious about. Are you thinking about a relationship of say..."this tra ramp goes with this angle helix"???

:)

Grover
05-22-2003, 06:17 PM
No not really. Weight controls RPM, helix defines the backshift and allows it to upshift in a certain way while controling belt pressure. The ramp controls the profile of the shift in relatonship to the force applied by the weight or secondary influence. Sure you can vary one to effect the other, but what influences does a taller ramp/ shorter style ramp have on a shift pattern with various helixs? Would a lower style ramp, like a 186 work better with a lower angle helix because the ramp wants to shift out faster and load the motor, vs a 145 ramp which wants to carry more rpm's and not want to allow it to shift out unless you change your helix to a larger number to try to get the same effect? -Grover :withstupid:

Dynamo^Joe
05-22-2003, 10:49 PM
I would like to separate the question and just elaborate on ramp profiles for now... :D

Have to keep in mind the relationship of the force the flyweight has with ramps that are thick and ramps that are thin.

I hope you have a Skidoo manual with the clutching pages that show all the TRA ramp profiles.
If you do, take a look at the 284 ramp. See how thick it is?
Now go back a page and look at the 144 ramp. See how thin it is?

With the 284 ramp, being the thickness it has, it holds the TRA arm closer to the clutch shaft center than the 144.
Because the TRA arm is tucked close to the clutch shaft, for whatever mass of flyweight you have in the arm, the engine has to produce a lot of rpms to create enough force for the flyweight to start to push the clutch closed.
Lets leave the same mass of flyweight in the TRA arm and just change the ramp. Lets neglect the profile "steep & flat" of the ramp. Analyze the distance farther away the TRA arm is from the clutch shaft. Being the pin mass is farther away from the clutch shaft, the engine now can produce less rpm to start to push the clutch closed.
The engine induces less rpm with the 144 "thin" ramp to produce the same force as the thick 284 ramp at higher rpms.

The thick ramp holding the TRA arm close to the clutch shaft will deliver a "revvy" feel to throttle position.
You will make the engine rev high before the sled starts to move with any substantial acceleration or speed.
The thin ramp holding the TRA arm farther away from the clutch shaft will deliver a more "torque" feel. The feel is as if there is a larger engine under the hood. The engine can induce less rpm to move the sled. You use more of the "meat" of the torque curve of the engine as you roll on the throttle.

Now we can analyze the "steeper hill" "flatter hill" detail with a good example of the ramps 145 & 228.
The 228 ramp is made from a 145.
It is commonly known that the 145 has a higher engagement over the 228, but after engagement, it fundamentally shifts with the same force thru the range to the end of the ramp as the 228.
The rest of the roller path provides the same angles, same hill for the roller to follow.
The 228 has the flatter angle at the engagement area of the ramp than the 145.
The engine induces less rpm to provide force to push the clutch closed.
The 145 has a slight hill for the roller to overcome. So how does the roller get up this hill and over it onto the flat part of the ramp?....Induce more rpm.

Here is the funky analogy:
Your kid's wagon is sitting on the road. You push the wagon by hand so the front tire goes over the flat of the curb and travels into the driveway. [228]
Your kid's wagon is sitting on the road. You push the wagon by hand so the front wheel has to go over a small wedge before the wheel can travel into the driveway. Oh...ramp you must go over. Cant do it unless you provide more force to overcome the angle of the wedge. More force...Oh, now the wheel can travel into the driveway.[145]


...good gawd, what have i said?!?!?!...
Ok ok, so I havent had enuf sleep lately.

but there ya have it.

Can elaborate on other details if there are more questions. :D


Now I will disclaim what I say by mentioning that Angles alone that people generally mention are only but a part in the concert of details that produce the push force when you apply the fuel.

mxzadr800
05-23-2003, 12:41 AM
Unbelievable info guys :D I'll share what i know...the fact that i know exactly 100% more than I did before I read this thread :thumbsup: While much of this info goes beyond a large % of riders it's nice to read and get some comprehension on what the function of the clutches and it's componets do. DJ, excellent descriptions and well written detail with very understanable examples. Keep it coming!!!!!

Dynamo^Joe
05-23-2003, 09:26 AM
The jug of water trick...

Items:
1 - Jug of windshield washer fluid [1/2 full] TRA Flyweight/roller assembly
1 - 6 foot length of rope "Changable" distance from Clutch shaft center to TRA RAMP
1 - Person to swing the jug on the rope. Clutch shaft Center of axis

Tie the rope to the jug handle. Measure 4 feet from the jug handle back on the rope and mark the rope with felt pen or tape.
Measure 5 feet from the jug handle back on the rope and mark the rope with felt pen or tape.


With the 284 ramp, being the thickness it has, it holds the TRA arm closer to the clutch shaft center than the 144.
Because the TRA arm is tucked close to the clutch shaft, for whatever mass of flyweight you have in the arm, the engine has to produce a lot of rpms to create enough force for the flyweight to start to push the clutch closed.


Here is the exersize. Simulate 284 ramp
Grab the rope at the 4 foot mark and start to swing the jug over your head. If you can, look at a clock with a second hand and swing the jug 7 times thru the air in 5 seconds. You will be able to feel right away if you have to increase your speed or decrease the speed within two attempts to make 7 revolutions in 5 seconds.


Lets leave the same mass of flyweight in the TRA arm and just change the ramp. Lets neglect the profile "steep & flat" of the ramp. Analyze the distance farther away the TRA arm is from the clutch shaft. Being the pin mass is farther away from the clutch shaft, the engine now can produce less rpm to start to push the clutch closed.
The engine induces less rpm with the 144 "thin" ramp to produce the same force as the thick 284 ramp at higher rpms.

Next exersize. Simulate 144 ramp
Grab the rope at the 5 foot mark and start to swing the jug over your head. If you can, look at a clock with a second hand and swing the jug 7 times thru the air in 5 seconds. You will be able to feel right away if you have to increase your speed or decrease the speed within two attempts to make 7 revolutions in 5 seconds.

Ok so this sounds like a kids game? Fine!!! Go do it in your garage where nobody can see it.
I will tell you this though, I have seen a few smiles on peoples faces after they've done it. Smiling because they could not believe how hard it was to get the jug to spin, but especially when I get them to do it 9 times in 5 seconds.
or...fill the jug up full of water. Want to see an analogy of the effects of accelerating a heavy TRA flyweight?...fill the jug up and do 7 in 5 again.
Some guys outright laugh after this exersize is done.

So im sure your memory will be jogged here when I mention that you have read this forumla in popular clutch tuning manuals.
F=[m][r][v^2] [v^2] = "V" squared. "V" being the speed the mass [jug] travels in distance per second.
Well lets actually look at some numbers here.
what is 2 squared? 2^2=4 What is 4 squared? 4^2=16....lets keep going. 2, 4, 16, 256, 65535, 4294967296..."big numbers aint they?!!"
This is what kind of forces that a flyweight exerts as the speed of the engine increases and the flyweight mass "pin weight" moves farther away from the clutch shaft center.

WOW, we have some big-as$ force numbers here. How can we compensate for such a great force the flyweight can push with?
Look towards the end of your TRA RAMP. Notice how the curve is?...Notice how the hill gets steeper "like the tuning manuals say"
If the angle of the hill gets steeper, then the hill makes it harder for the flyweight "roller/pin assy" to climb the hill. Increase angle of hill....harder climb yet.

Umm, does the "Wagon wheel going up the wedge sound familiar now?" he he he....

I like to use the word "PUSH" instead of shift. At high speeds near full shift, the flyweight pushes with great force. Great enough that the engine can lose rpms. To "COMPENSATE" for the push, you introduce a change of angle "steeper hill in this case" to "RESIST" the force of the flyweight. Now that there is something to resist the push of the flyweight, what happens to the engine rpm? The engine has to produce more rpm to keep the push the same magnitude for a "straight shift"
Again, its the "wagon wheel going up the wedge"
Increase angle...makes it harder to push.
Decrease angle...makes it easier to push.

I have not really done much grinding to TRA ramps. Not enough to quantify me saying that I have any experience at it. But from the little I did, It is nearly unbelievable how much a tuner can make an engine drop in rpms by accidentally removing 2 thou [.002"] from near the end of a ramp. On small cc engines of 600 cc's or less, I will say what I measured was drastic rpm change.
Gained a wealth of knowledge there, but drained my pockets of $$$ to go buy new ramps.

When it comes to flyweights that "P", "AC" & "Y" use, I coulda kept the flyweight manufacturers in business by just supplying me with weights. My gawd I could fill a few 5 gallon pails of flyweights I have grinded, machined...blah blah blah, you name it, Im sure I did it to a flyweight. HAHAHA...So in the end, I do know how much .001" makes at the start and/or end of a profile.

I'll tell you man that I am happy using a TRA. Cannot beat $.75 worth of setscrews to change flyweights than having to buy a handful of big dollar flyweights like P,AC and Y use.

Mikadoo
05-23-2003, 05:48 PM
Originally posted by Dynamo^Joe@May 23 2003, 08:26 AM


I'll tell you man that I am happy using a TRA. Cannot beat $.75 worth of setscrews to change flyweights than having to buy a handful of big dollar flyweights like P,AC and Y use.
You said a mouthfull Joe!
Most wanabe racers will use a AC secondary and a Polaris primary while getting there a$$ stomped time after time. Then they stand around scratching there head wondering why a stock well clutched TRA just blew them away.

P.S. keep up the work, you are a wealth of knowledge. Also, I went to the CPC site but for some reason I see nothing about the DOO secondary springs such as the blue/white you highly recommend.

baddude
05-23-2003, 08:40 PM
I am with mikadoo on this also.I looked, and seen nothing on the doo sec springs. :nervous: I was loooking for the Blue/white as well to try a couple of things.

hillpounder
05-24-2003, 11:34 AM
The cpc spring is a cat spring, it's slightly larger in diam than the doo spring but will work in the doo secondary. It's a stiff mutha.

Dynamo^Joe
05-25-2003, 01:46 PM
Originally posted by Mikadoo@May 23 2003, 04:48 PM

P.S. keep up the work, you are a wealth of knowledge. Also, I went to the CPC site but for some reason I see nothing about the DOO secondary springs such as the blue/white you highly recommend.
Umm...thanks for kind words, but really I only know my notes. From my notes I can remember problems of why things worked and why they didnt. Anyone can do this if they keep notes. They dont have to be in great detail either...just make notes as small as possible only recording the clutch details/settings/temperature measurements and a few seat-o'-the-pants comments. That is all it takes.
I know some formerly novice clutch tuners who basically have kept no notes up until 3 seasons ago and now I regard them as knowlegable tuners who I would throw problems at them that I have.
They keep notes and they read them over and they forget nothing.
You can have the most constructive conversation with someone who keeps notes, even from someone who only trail rides. Man, I tell you there are guys who are a wealth of information on what belts to use on your sled. Me, I know nothing about belts, but some trail riders have tried every brand and they recall part numbers per brand and can even tell you how a belt feels in the midrange. They'll tell you what belt to stay away from, what belt is good for going fast :hallo1: , what belt is good in snow,:) what belt will wreck your clutches when they blow....:cussing:
....and they have a little notepad tucked away in their jacket pocket beside a broken pencil, which they carry all the time. :thumbsup:

That CPC spring is not a Dooey spring. It is fit for ACat.
Dalton sells it.
PSI sells it
Cutler Performance Sells it
I sell it. "he he" :sly:

Dynamo^Joe
05-25-2003, 01:59 PM
SUNDAY 30th
Rocketman's Polaris 440
Rocketman started the day off playing with the Thundershift arms again.

We wanted to see how they worked on the sled with the composites in various positions. Knowing what bolt/washer combination was the heaviest/lightest, Rod first started placing the heaviest composites near the Pin. Check engagement and go for a run to see how it shifts.
The engagement come down about 500 rpm to 4900 and the sled was very aggressive. Nice holeshot for the setup but started to slight over-rev when getting to top speed.
He ran around with that for a bit then wanted the engine to have more flash thru the clutches. Rocket liked the "torquey" feel, but wanted the engine to respond with a little more jazz on the bottom of the midrange.
Rocketman came in and removed the composites going to extreme opposite loading the heaviest bolt/washer near the tip of the weight.
Engagement now is at about 5400 or so. Sled is revvy and pulls ok thru the bottom and midrange, but the engine dropped rpm at the high speeds.
He still got about 85 mph at 8300 rpm but the sled was not backshifing nicely but pulled hard.
Rocket finally found a very nice spot where the composites pulled the engine straight as it could. It seems that the engine pulls about 8300 "tach rpm" real hard and slowly towards high speed it climbs to 8450.
Out on the Speedcheck radar the Pro-X was getting speeds of 82 to 85 mph…depending on holeshot. Better holeshot and low amount of spinning, the better the top end.

Ok, the day is changing, the sun is coming out, lets all look at our Piston wash. The wind died down and the sun was not bad. Still cold out for working on sleds. All of our piston wash seemed to be about the same. Plugs look nice.

Rocketman changed the secondary springs to try and see if the top end rpm would change. He went from some kind of Purple Secondary spring that we have no idea what it is...to a Beige Ski-Doo spring, and a Blue-Goodwin [Ski-doo]
By the end of the day with choosing a spring and adjusting the pretension he got 85 mph.
Gearing is stock at 22/43.
The Thundershift definitely show their usefulness today. Impressive run at 85mph fairly consistant of only 1 mph drop.

Rehab with his Pro-X 440 kind of dropped out of the Testing picture as he spent the day trying to fix his "loading up" problem. He played with the airscrews, in and out, cleaning the carbs, checking plugs. Tough luck for him. That’s ok he will get back in the picture when he gets his engine running right.

*Dynamo's 2Kzx-440*
Saturday I installed the CPC Blue/white secondary spring and played around with it for a bit.
The Problems:
2000 mxzx is over-revving 87-8800 rpms.
Nice engine flash. Shifts fairly straight yet you can run it right off 8800.

Sunday's Plan/Solution:
1] Add weight in Primary arms?
2] Change Primary Spring to lower finishing force in lbs?
3] Lower Cam number from 47-41 to 48-44 to bring engine down?

I figured lets go back and make that other spring work. I don't like to say "Try" that other spring...I wanna MAKE it work.
Trying to make something work the best it can, regardless if it works the way you want. In the end I figure you learned "Troubleshooting" a system.
Take out Blue/White and back we go again to the CPC green/white
Secondary Spring Details:
The compressed force to coilbind for the Green/White is around 125 lbs to 130 lbs. [17 lbs pretension @ 8700]
The compressed force to coilbind for the Blue/White is around 130 lbs to 135 lbs. [17 lbs pretension @ 8800]

Really I did not want to play with the clickers, but I figured what the hell, I have like 5 hours of daylight left. "Lets go burn some gas"
Revving at 8700 as such I turned the clickers from 4 down to 3.
Took a run and pulled real good outta the hole. The midrange was getting weak and the engine really dropped off to above 8000+. 76-77 mph on radar.

I changed the pretension on the Green/White from 17 lbs to 22 lbs. I figured I would go high on the pretension. I thought that all this would really do is prolong the engine from falling off. I was right.
The holeshot was nice, midrange was similar strength. The engine stayed a little longer "in feet" down the track with the engine falling off to about 8200+. 79 mph on radar.
I went down to 19 lbs pretension and about the same results...79mph. PATHETIC!
Im starting to think that there is something wrong with this spring. I did a few more runs and when I got to full mph, I slam on the brakes and kill the sled. Pop the hood and measure secondary sheave temperature. I put my hand on it and it is warm/hot. Im losing mph in "HEAT".
Hmmm.......

More runs.
"Clicker change"...up to #5.
Holeshot reasonable...engine 8700...all that did was prolong engine at 8700, midrange average and mph still around 80mph.
"Clicker change"...back to clicker #4.
This seemed the best at 17 lbs. I went to shore and spend about 10 minutes changing the spring location about 4 times to get 18lbs. I finally found it.
So with the run after the sled being cold, I got 81mph with 8700 rpm down most of the track and going across the radar at 8600 rpm using 18lbs of pretension.

Ok...Notes to write as there is too much info to remember.
Well looky here...The fastest speed = 81mph
Fastest speed was at 8600 rpm on clicker #4. Clicker #3 SUCKS!
8500 across radar...slow. 8700 across radar...faster. 8600 across radar...FASTEST.
Well well well, I bet that this engine pulls the best if I can get it to rev 8600 on the tach. Hmmmkay.
WE HAVE A NEW GOAL FOR THE WEEKEND!!! >>>We want 8600 on the tach.<<< Many may notice that when I talk to people about clutching, I always mention two words..."tach rpm". I have measured several tachs and they read high 99% of the time. My personal tach reads about 175 rpm high

New Problems arise:
I did at least 4 runs with these details.
18lbs secondary pretension.
Clicker # 4
Rpms are mostly at 8700
Pulls hard slowly down to 8600.
Mph is 81.
I get to shore and go near my tool box. I look down and see my new belt I just bought. I could just slap myself for not putting it on right away. Too many beers and tequila&#39;s the night before. :sleeping:
I installed the belt and what happens? THE PROBLEM - Rpms came right down to 8500 going across finish line. 80 mph.

Well, I did many runs and increased the pretension up a bit, then back down to 18 lbs. For some reason the sled is now getting wishy-washy while doing runs back to back. I keep thinking of the heat from that Green/White secondary spring
The speeds are only high when the sled makes its first run. After that the speed changes every run and never see 81 again.
I do a run, then lift the hood and check secondary temp. Cool to touch. I do more runs and same thing. Nice temp, but mph are all different.
More runs...secondary gets hot.

Looking at this, all of us were baffled.
I say..."Lose mph like this...LOSE THE SECONDARY SPRING."
Green/white..."YER OUTTA HERE!" Back in goes the CPC Blue/White and now we did some runs they were all consistent regardless of the rpm being higher.
I knew I was down a mph just by my holeshot.
The runs were the same all the time pretty well.
Ok so now were back to high rpms, but fairly straight shifts.
Check secondary temp...Cooooooooool. He he hee....Im just giggling and gettin all warm inside. Im thinking that if the secondary is now this cool, then im getting pretty efficient clutching. There is the capacity to maybe add more weight in the primary now? Maybe lower the clicker? The secondary being cool like that im thinking that there could be more "push" from the primary.
What to do...What to do?...

So this day we accomplished:
1] GOOD JETTING. Piston wash O.K.
2] SHIFT PATTERN. got the sled to pull fairly straight all the way to top end while yet over-revving, but straight rpms. Found the honey spot of pretension that worked the best.
3] FOUND BEST RPM TO RUN AT ON TACH = 8600 [Actual engine rpm 8425 +/-]
4] NEW BELT BRINGS RPM DOWN
5] INCONSISTENT MPH = Bagged Secondary Spring. Solution, "TOSS SECONDARY SPRING".
6] HIGHER MPH. Woo, 81 mph.

Problems We Still Have...
1] Over rev
2] Rpms still fall off slightly after 3/4th mile.

Planning for Monday...
1] Bring rpms down by adding set screws [weighs] to TRA levers.
2] Make present cam 47-41 work as we liked the shift.
3] Figure out why engine falls off and pulls down to 8600 waaaaaay out there.

Reasoning For Adding Set Screws...
I would rather add more weight to the TRA levers because of the secondary spring is causing the engine to rev.
The secondary is torque sensitive. The secondary is OVERCOMING the PUSH from the Primary.
To make the Primary OVERCOME and PUSH open the secondary, we have to add slight weights.
We know that adding a several 10ths of a gram will make Absolutely no visual difference to the engagement, but when the sled is going full speeds and the TRA Levers are swung out...The force that those 10ths of a gram will be VERY SUBSTANTIAL.
Worried about backshifting? NO!!! Not at all. We have a huge spring in the secondary. It has a lot of compressive force.
It has moderate pretension, but when the secondary is turned open in several degrees at full shift, the pretension is very high, much more higher in lbs of force than the Ski-Doo beige could ever put out.
So do I think that adding flyweight will be bad for backshifting?....Nope, not for a second.
I will only add maybe a few grams. Not a ton of weight.
Secondary will backshift awesome.

Day 3 coming up soon...
Kick ### results.

Mikadoo
05-26-2003, 09:19 AM
Ok Joe, so I&#39;am going to these sites to find a CP blue/wht. secondary spring and this is what I get:
cutler@enol.com I get a Korean site [this was taken out of American Snowmobiler mag].

cpracing.com I get "no page to display"

psi performance show a red/wht.--gr/wht.--pink/wht.--black/wht. all under cat springs but no blue/wht.

And finally Dalton has it for $22.00 [not bad] but $19.95 to ship!!!! Haven&#39;t these people heard of U.P.S.? Delivering by horse back is not commom practice anymore!

Dalton industries is out of the question, so whats up with these other sites? I&#39;am not totally retarted on a computer but close.

Dynamo^Joe
05-26-2003, 09:49 AM
This is down
http://www.cpcracing.com/
I do not know why it is down, but there are many times I connect and I get [The page cannot be displayed - The page you are looking for is currently unavailable]

I know the price is expensive to ship.

On PSI:
The Green/White spring they mention there...Cutler stopped production of that G/W spring back in 2000.
Since Jan-2000 the spring has been updated to the Blue/White. B/W is a totally different spring than the old G/W.
So I would talk to them and get them to actually "Touch" a spring with their hands to see what color it is.
From looking at their website a while back, I dont think they have updated in a long time.

Check D&D Performance to see if they sell that spring. Dalton makes DnD helixs I do believe, so DnD might have one or they could deal a CPC spring for you.

Or just Call Cutler in Idaho.

Umm, if you were going to get this spring, I remind you that I test this with "Roller" secondaries.
With the button secondary and this spring it is a heavy load on the buttons. Plus, being a button secondary, using this spring pushing the sheave against the buttons, it is like having a lower number helix...compared to a roller. "friction" between the button and helix is increased quite a bit. Ok im not being factual and do not have numbers to back it up, but the button wear tells a story.
For increased rpm, you should just typically have to Compensate with a little more flyweight.

800MXZ
05-26-2003, 11:41 AM
Mikadoo - West Shore Parts and Service in Houghton Lake carries a full line of CPC springs if you are ever in their neck of the woods.

Mikadoo
05-26-2003, 04:32 PM
Joe, I will be running a standard secondary. I run out of test time this winter and will be trying a 50/44 coated helix from a 53/47 and a 200/380 drive spring from a 200/290 along with a set of 280 ramps from 295&#39;s. [19.6 pins no change].
I know testing should be done one thing at a time and I&#39;am pretty sure all I really need to change is to the 50/44 helix to stop the dreded over-rev.
The heavier spring idea [I hope] will keep engaugement the same but add more belt squeeze and get the heat down.
Then, you come along with all the talk of more belt squeeze in the secondary, a subject often ignored by most. It all makes sence but it looks like a Skidoo white spring is probably enough?
Clutch heat has been a real issue for me and as you say it is all wasted power. I have said all along that the secondary is a major tuning tool where most say the main fuction is backshift and to do ALL tuning with the primary.
This set up is in a 00 MachZ longtrack[1 1/4x136] 240# rider.
I&#39;am not strictly into drag racing but just the average want a fast all around set up. Do you think the 280 ramps will be too aggressive?

MXZ800 I do get to Houghton Lake once and a while, where exactaly is West Shore located from like Spicers?

800MXZ
05-26-2003, 11:12 PM
Mike - From Spicers, go left from the parking lot, drive about 1 mile-2 miles approx thru 2 lights. You will come to an intersection with a road that runs parralel with the west shore of HL(buissnes 127). Turn right (North) and drive about 2 miles till you come to a road that goes east (towards the lake). It is only about a block long till you get to a stop sign, go left (north). Follow the windy road north till you come to West Shore marine. The are a big A/C and Poo shop, allot of PSI big bores.

They will dog ya hard if you tell them you are riding a Doo though, they are kinda bull headed. But, they are the only place that carries any perf stuff around HL.

If you want a ride up there, let me know. I am close to HL and go there quite a bit. email me at the address below.

Dynamo^Joe
05-26-2003, 11:35 PM
I am not into drag racing either Mikadoo.
I have not been into drag racing since 1992 or thereabouts.
I got into watercross racing and did that till 97.
Now I just trail ride. I run mxzx 440&#39;s and now a new rev440 and that&#39;s it. Never again a triple or sled larger than 500 if I can help it.

I build clutch kits out in the field. I mean extreme trails where if you do not have at least sno-pro valving, if you tried to keep up with us, you would break your rails in 1/2.
The 800REV mule we had this winter had 01 mxzx shocks in it to flog on the trail. Riding in extreme terrain where we get a major sweat on and beat the sled really puts a severe load on the clutches. Heh, want to make an engine lose rpms real quick?...Just add 2&#39; to 4&#39; whoops that run for a mile.
I figure because I tune in such a harsh environment, this is why my kits work in pretty well everything and all you have to do is change the flyweight per discipline.

My trail kit that I ride all season is the same kit that I will drag race with and that others are racing with right now. People think you must change helix for disiplines...I say "nope" not if you have the right angle of helix for the speed you are going at any point in time. I have factual data including whooping a$s to prove it. he he he

Basically everything we do is out on the lake first to get the best mph.
Then we take it on the extreme trail, load the clutches hard by driving hard.
Change the amount of flyweight to suit...or maybe change the primary spring. Big-a$s bumps load the clutches heavy and will pull an engine down. So we compensate for the data we write down and make the flyweight right for extreme and it always works good on the lake or road for killer top end.
Helix stays the same...secondary spring stays the same.
You just do a step by step process and analyze your data. Temperature tells such a huge story and will raise many questions for yourself...this is where you learn to make your clutching run good.
Make that secondary cool to touch...compensate with flyweight for rpms you do not like...pick a clicker you like that has "fun factor" Keep notes and do what your notes tell you to do.

I am getting back into drag racing this summer. Will be tuning an 800 and my 440. Would like to hit Cosdra circuit stuff but more than likely will hit all the northern stuff up in all the French towns.

I be back later to ask you questions on your choice of helix...Im curious to what you are saying there. :)

Dynamo^Joe
05-27-2003, 08:49 AM
I found this....

http://www.storesonline.com/site/256083/page/31600

http://www.storesonline.com/members/256083/uploaded/logo.jpg

Dynamo^Joe
05-27-2003, 10:23 PM
***DAY 3 MONDAY***

Ok so we know what happened yesterday and have a good plan for today.
In the evening we were talking about going up a tooth in the gear. 21/43 is original, and how about 22/43. Reasoning is that Rocket man is getting about 2mph on top end compared to me. Maybe also with that gear we could keep the midrange stronger and thus go farther in feet without the engine dropping off like it does.

We did something I really do NOT like to do. Rad Chad went down and changed my gear to 22 before we even made a run. I kind of had a chuckle as I wanted to make a few shakedown runs with the new CPC-Blue/White secondary spring and [47-41 Dalton Helix]. "Oh Well” Heh, we will just play with the cards I was dealt with. I went out and did a run around the lake getting on and off the fuel. "Jazzing it” Ok now were warmed up...HAMMER DOWN!!! WOW, 8800 rpms. WOO HOO. Good air to make overrev this morning. Were up 100 rpms from yesterday evening.

I come into shore. Rad Chad said."We going to add some screws?" Yep, you bet.
After each screw I went for a few runs down the 3/10th mile.
1 Screw [0.8 grams] - 8800 rpm thru top end of midrange, then engine pulls down to 8700..maybe 8650 - 83 mph.
2 Screws [1.6 grams] - 8700+rpm thru top end of midrange, then engine pulls down to 8600..and $change - 84mph.
3 Screws [2.5 grams]- 8600 rpm thru top end of midrange, then engine pulls down to 8400..and $change - 85mph.
The 4th change was a screw that weighed [2.1 grams]. 8600+ rpm thru top end of midrange, then engine pulls down to 8400-8500.
- 86mph "Hard to tell"

WOO HOO! I found the honey spot of my engine "I do believe" Looks like the power is real strong lets just say between 8550 and 8650 rpm.
We did back to back runs with that and got an average of 85mph.

THE PROBLEM!!!
That 8400+ "Tach rpm" is a problem. Lets look at this now. Over all the testing we did, I pulled of the steaming mph @8600+ rpms. I still go across at 85mph with pulling down to 8400-8500 rpms. My midrange is screEEEAAAMINNnnn. Holy CRAP!

I knew what was going to happen already if I changed the clicker, buuuut I figured "what the heck" and let&#39;s prove what will happen.
Clicker to 5 = 8800+ rpms. Low mph
Clicker to 3 = DOG! "Bow wow!!" HAHA.I&#39;&#39;m not even going to say how low I was revving.
So I continued to race against myself with the radar gun. I ended up changing my pretension with the hopes that I could prolong the engine at 8600 ~ thereabouts before pulling down.
I went in to shore with 17lbs and spent a few minutes changing holes to find 18lbs. AHH, TRA secondary are BEAUTY for getting 1 to 2 lbs increments. I do make my P-85 and ACat secondary to have the same capacity by drilling those adjusting holes in 2 other locations.

Out on the radar again with 18lbs I consistently got 85 mph...Back 2 back. It seemed that the engine DID want to stay at 8600+ a little longer in feet down the track before pulling down to 8450-8500.

***END OF DAY***
Ok well now its DRAG RACE time. In that evening Shooter, Rockeman and I dragged about 10 times.
Shooters would hookup hard all the time with little spin and get a holeshot a bit on Rocketman and I, and then we would reel Shooter in and pass him. Every single time.
Rocket man would come out strong on the big end and pass me by the radar trap about 2-3+mph faster.
HAHA, I was PISSED, once Shooter pulled across right in front of me and I thought "great, I&#39;&#39;m getting all his snow dust” He pulled across enough that I kept a straight line to go by him. I would reel him in and pass him.
The second race he pulled across me again. HAHAHAHAHA...Ize just thinking..."Ooh, well, I&#39;&#39;ll just have to pull out and pass him"
rrreeeEEEEEOOOWWWWWwwww...*WAVING BUH-BYE* "SeEyA sHoOtEr” Oh I had to say that out loud under my helmet. Ohh you don&#39;t know how much fun that was to SLAY in the midrange like that.

Rocket man with his 2001 Pro-X 440 basically just adjusted his pretension for the day and messed around with the THUNDERSHIFT flyweights. Those babies are BEAUTZ!
Rocket man basically kept the same weight with in a gram and moved around the composites [washers/bolts] He was looking for more engine flash thru the clutches.

***OK Day is over***
Time to plan for tomorrow [Tuesday] over a few beers & food.

So this day we accomplished:
1] GOOD JETTING. Piston wash O.K.
2] SHIFT PATTERN. Got the sled to pull fairly straight all the way to top end while yet over-revving, but straight rpms. Found the honey spot of pretension that worked the best.
3] FOUND PROPER WEIGHT. Added 2.1 grams to get engine down and pull like a mad wh0re on payday.
3] FOUND BEST RPM TO RUN AT ON TACH = 8600+ and change.
4] CONSISTENT MPH at about 85. We increased 4 mph average from yesterday
5] GEAR CHANGE worked as we made it work.

Problems We Still Have...
1] Revs right on 8600 "tach rpm" thru midrange to top end, then pulls down a hundred rpm or so.
2] Mph is still low...were geared for 93mph and we&#39;re only doing 86 topped out.

Planning for Tuesday...
1] Raise rpms at the big end.
a) Change Primary spring to higher final tension?
Or
b) Change cam from 47-41 to what? Cam with a lower final number?

Reasoning...Everything we planned on helped to change rpms to pull hard. Everything we thought that wouldn&#39;&#39;t work we predicted what the effect would be.
Only things left is to change primary spring or cam.

Well, I&#39;ll tell you all this right now. Every damn Ski-Doo I have drove has done what people call [over shift] what a cheesy term, but it&#39;ll do for now. You run the sled out to the big end and dammed almost all of em are mph low compared to other brands.
Best suspicion is that the arms are weighted too much on the end and when the primary is closed [full shift] the arms want to stay out there and not backshift. The primary pushes very hard.
Why?
The secondary is "torque sensitive” If the secondary cannot resist the force being put out from the engine, the secondary will stay opened and not backshift...it will not compensate...I really like that word in this case..."Compensate" and resist the engine so the engine will fall off or lose rpm.
Another thought on top end loss with Bombers is the secondary spring. Heat tells great stories. I removed the oem secondary spring and installed one that has more compressive force at rest and full open. The spring pushes the sheaves together quite nicely gripping the belt hard. Beige spring...My opinion, not enough.
Another thought is that it takes a ton of pretension waaaay out there at full open secondary. The beige does not rise enough in rate under tension at full shift to help the sheaves grip the belt.

So now I have a [for lack of better numbers] 380 lb final tension spring in the primary.
To keep the rpms from falling out there at peak mph&#39;s; Why would I want to put a spring in that has a finish force of say...390 or 400 or 410?
The arguement could be that the primary is pushing too hard at peak mph. The primary spring with a higher final force in lbs would resist the push of the flyweight and keep the engine up there, right?!!

Lets think now that if you put more spring force in the primary clutch to resist the flyweight to increase rpms and you will take away from the capacity the secondary can do.
The engine is pulling down. The secondary cannot resist the push from the primary thus keeping the rpms straight to top speed.
Im gonna leave the primary push like it is and get the secondary to grip the belt better.

SO...Knowing the details that the secondary is in right now with that spring and pretension...I get the straightest shift I can. The backshift in the snow over at shore is very nice indeed.
CAM ANGLE under good belt deflection will in this case change rpms at top speed.
...This is the route I will go.

If 41 degree is still pulling my engine down way out there by 100+ rpm, I need a finish angle that is lower. Theory goes...Lower cam number, higher rpm.
So tomorrow a 47-37 is going in and were going to shoot for that 100+ rpm.

Tuesday results almost made me wet my pants. He he

Dynamo^Joe
05-29-2003, 09:51 PM
Quotes Mikadoo
Joe, I will be running a standard secondary. I run out of test time this winter and will be trying a 50/44 coated helix from a 53/47 and a 200/380 drive spring from a 200/290 along with a set of 280 ramps from 295&#39;s. [19.6 pins no change].
I know testing should be done one thing at a time and I&#39;am pretty sure all I really need to change is to the 50/44 helix to stop the dreded over-rev.

Well, I have to say...Im lost. haha. You changed too many details for me to follow. I do not know what the difference between a 280 & 295 is. I have no idea how they would react comparatively.

You have a 53/47 and want to goto a 50/44. You are hoping to stop the overrev by this direction?
Im assuming that then the coated helix is an HRP or a SPX helix. I am thinking because the 50 is lower than the 53, you are going on the account that the 50 coated is "supposed" to act like a helix much larger than the 53.

If this is so, Im not too keen on the accuracy of the angle that the coating is supposed to deliver. But lets say that this actually will work to keep the rpms lower. Now you install a Blu/wht spring, this should push the rpms back up because of the belt squeeze that the spring provides.

The heavier spring idea [I hope] will keep engagement the same but add more belt squeeze and get the heat down.
From your primary clutch, you are removing a 200/290 and installing a 200/380 spring. Yep, then your engagement will stay the same. You will find just from changing the spring that the engine will be more "revvy" on the bottom end. That is 100 lbs more force at full shift you are installing to resist the push of the flyweight...You will have less belt squeeze.
Im gonna bet that say this was the only change you make, somewhere in between 35 to 50 mph your engine rpms are going to start to climb. I&#39;ll further guess that when your sled cannot get any more top speed your engine will be minimum 800 rpm higher than peak. Im gonna disclaim here that this is just a "Fun Guess". he he :)

Then, you come along with all the talk of more belt squeeze in the secondary, a subject often ignored by most. It all makes sence but it looks like a Skidoo white spring is probably enough?

well, it could be enough. I swear the Dooey white looks just like a GW/Grey. Yeah it has a lot of final compressed force but I do not think it has the same torsional values as the CPC-Blu/Wht.
Ok so this torsional value I mention is to do a pretension test...at full shift.
Install both springs so that they both are at the cracking pretension you like. [Say 18 lbs cracking on one pull]
Ok, now keep pulling. Keep pulling so the secondary sheave turns open counterclockwise until you cannot pull it until it stops. What is the measurement on the White?...What is the measurement on the Blu/wht? This value is one I look at all the time.
I know that pretension will win a race. I know that high pretension wins races. This is no difference in trail riding when you want to go full speed. we all know, at say 1:1 shift the belt does not cover much surface area on the secondary sheaves. The belt circle is small radius. You really need the sheaves to clamp that belt at this ratio and clutch rpm. The belt does not spend much time going thru the sheaves so you really need the compressive force to keep the sliding sheave from moving out towards the direction of the chassis, and torsion to keep the sheave from turning open in degrees counterclockwise.
So the next test would be is to go HAMMER DOWN with both springs. Get to top speed and stay there for a bit, then lock the brakes, kill the engine, pop the hood, measure the secondary temperature with your hand.
The temperature that is lower will be the more efficient spring.
If you have an overrev condtion, then what do you do to push the secondary open a little more?....a few 10ths of a gram in the primary wouldnt hurt.

.... I hope I am able to paint good pictures with words here.???

tb2
05-29-2003, 11:52 PM
Flash is good, rpms stay right where I want them all the way thru shift ratio. top end is good. Problem is belt slippage at high shift ratios causing poor belt life. I say I need more final rate secondary spring pretension,and or lower finish angle on cam, then I am going to need more weight in primary to maintain rpms. running 20lbs straight 50 beige spring. Any Idea how much increase in spring pressure or lower cam angles needed typhically to help.

Dynamo^Joe
05-30-2003, 02:34 PM
Originally posted by tb2@May 29 2003, 10:52 PM
Flash is good, rpms stay right where I want them all the way thru shift ratio. top end is good. Problem is belt slippage at high shift ratios causing poor belt life. I say I need more final rate secondary spring pretension,and or lower finish angle on cam, then I am going to need more weight in primary to maintain rpms. running 20lbs straight 50 beige spring. Any Idea how much increase in spring pressure or lower cam angles needed typhically to help.
Hmm...the thing I would look at to make a decision is "when" am I going to need more flyweight.
You want to change a detail in the system that will make a substantial change that you could measure.
Then once you collect your data from your runs, you can make adjustments to compensate for issues that arise.
Ok you recognize that you have heat which indicates HP is going up in the air.
You know what secondary spring you have and measure its compressed force in lbs.
If you change the secondary spring to one that has more final force in lbs, then the heat should be less in testing.
What if you pick a secondary spring that will clamp the belt so hard that the engine rpms actually start to climb as you accelerate?
Find the clicker number that will give you the straightest rpm...regardless of rpm you have.
Dont try to lower the rpm with a clicker...just use the clicker to find the straightest shift.
So you choose a clicker that makes the engine run the straightest to the sled&#39;s top speed.
Have high rpms in this fairly straight shift?....compensate and add flyweight to pull the engine back down.
There will be a point along the way of when you get near your top speed, your engine will start to lose rpm.
You don&#39;t want to change the primary details.
You want to use the secondary to capture the push of the primary.

In your notes you should be able to reflect on what you achieved.
Cooler secondary
high rpms
straight[est] shift
Brought rpms down with flyweight.
losing rpms at high speed.

You want to take care of the falling rpms...
must resist the push of the primary with a lower "final" angle on the helix.
Here though I would want to make a change that is substantial enough that you can measure an rpm change.
You like 50...well you could go with a 50-42, or 50-40 or 50-37...
...think these numbers are too low? Are they?

Look at the specs for the Beige spring. Look at the final compressed force. I think the manual says 85 lbs.
I don&#39;t see why you cannot go for a 100 or 105 lbs secondary spring. **dont forget that personally I measure springs to coil bind less 1/16" inch. Manuals and catalogues measure installed and full shift. I like to bottom out the coil
BUT...I would try to have a look at the springs and get the most coarse amount of coils.
For example if the Dooey White is 6 coils, then try to find a 5 coil spring, or at least try to find a spring with coils that are spread farther apart than the beige.

Here is a tip...Dont pick a GW/Blue, G/W Grey, Dooey White, Erlandson Orange.

Have a look at charts from Erlandson, PSI, Hotseat, Cutler Performance Center. All polaris springs fit Doo. 90% of springs that fit Cats will go into Ski-doo "with a little difficulty"
Cat springs usually touch the buttons or rollers in a Dooey secondary. They might be a beotch to go in, but once under pretension load the diameter of the spring is smaller and will not touch anything.

Keep good notes. Your notes will give you the direction to go once you start changing parts.

Mikadoo
05-30-2003, 07:18 PM
Joe, I was writing you a big responce off-line and forgot to sign on before hitting the add reply button and lost it all :cussing:
I will be dammed if I will write it again!!!

GLHRACING
05-30-2003, 09:32 PM
Joe,

Let us not forget that at high speeds or rather high shift ratio&#39;s the belt speed is up around 2600 ft-per minute. This by it&#39;t self creats alot of heat just from the centrifugal force trying to pull the belt up the sheave as well as the bending action the belt goes through. I have spent some pretty good time studying the effects of belt bending over the years and unfortunatly it is a flaw of the CVT drive.

Rember that the belt is also the connecting heat sink between the secondary and primary. Therefore when doing high speed testing don&#39;t always assume the heat is generated from just one clutch. Likewise if you have just done a 2 mile run and the clutches are the same temp don&#39;t assume the clutches are dialed perfect. The belt will eventually transfer the heat from the primary to the secondary and vise versa. This is often an overlooked situation.

GLH

snowmutt
05-31-2003, 11:20 AM
well here s a story&#39; i have a 00mxz 500 and a friend had a 440zr sno pro now this guy was a machanic on these things for a living he had this zr wrapped so tight if it let go it would throw sherapnel for a 100 ft away w/ a set of bear cat clucthes and nology wires he would pull the air gage out every am and tinker till noon so this thing should make the space shuttle look slow well heres the point he stuck all this $$$ and time twiking w/ pins weights and ramps if it could be ajusted it was into the so called rocket and here i was was on a stock 500 and yeah he had me til i tune the clutch i put a goodwin clucth kit in and a roller seconary i followed the specs from goodwin and went riding hmm a 2hr set up and i was riding we both have studs 136 in mine and 144 in his we lined them up and guess what that so called rocket of his was moping like a dog w/ his tail tuck under his ^%$^%$ i got him on the line and at the end by a sled length or two both sleds are
small bore twins that pull 100+ on the gun but do you need to put all the time and $$$ to do the same thing for a few bucks you get a kit that works just as good the trick is putting the power from the mill to the snow the right wt to power ratio is the key look at the snow pile at the line the one thats bigger is the one that left a few ponies unused hooking up at the line thats why some of these big 700 and 800 s are scraching there heads when a little cc sled spanks them as we ride off everybody wants the biggest badest snow ripper on the white stuff but there is a limt of putting it to the ground the right combo is custom fit to you and your sled what works for you may not work for them it all has to be in line power wt ratio the best thing for me is my yellow hornet dosnt need to play in the litter box for hrs and i have the bragging rights of putting the putty cat back in the litter box oh by the way im not bald ether from scratching my head trying to figure out why i just tell him its a fact bees fly faster than cats run ! :p ill agree w/ alot of you guys you have to find the right combo and that comes w/ r &d and $$ we need to keep from beating up each other and peserve our sport how can these harly riders go around w/ loud pipes all summer long and nothing is done about it and us sledders have a noise issue every yr ? were in the sticks and there right out your front door !! :cussing: 5mo till the harlys get put in there box think snow !!

Paul_Aris
05-31-2003, 11:52 AM
Joe, What kind of belts do you use? I have always heard to run the OEM belts because that is what he clutch was set-up with. There are different manufacturing tolerances and compounds used. If I could run a Dayco Ultimax 2 or a Gates Extreme I could get them just over cost and save a bunch of money. I would think it would be alright as long as the clutch was set-up to the belt used and you always use the same belt. That would be if their tolerances were tight enough that you got a similar belt each time. Any thoughts?

Mikadoo
05-31-2003, 12:31 PM
Ok Joe, it&#39;s the next day and I will respond to your answers in order because I have no idea how to do multiple quotes.

#1 You say you dont know the difference between ramp profiles? I take it then you go with whatever is stock in the sled?

#2 Yes the coated helix is from Doo&#39;s parts book and it better be "as advertized"! Reason going to try a lower finish angle is to help stop over-rev on top by loading the engine more. I have found in my limited clutch tuning abilities that for every degree you raise OR lower angles = 100 RPM&#39;s.

#3 Going to try a stiffer spring on the high end to add more belt squeeze. Now you are saying it will be less belt squeeze?? Unless I read all your post wrong, you are now saying less pounds = more squeeze?
Why do you want big pounds with your muched talked blue/white secondary spring? Are you saying less spring in the drive and more in the driven? This is the way I read you now. Everyone I know that&#39;s into racing runs tons of spring in the drive.

I know adding-subtracting pin weight plays into getting the desired RPM&#39;s but in most cases if you get the desired RPM&#39;s on top you lose on the bottom. Sure, change clicker positions and usually get back to square one, so where is the line where it will finally get a straight RPM all thru the run?
I can achieve a desired RPM for the first few feet then the over-rev begins. Clutch heat, He11 yes! Make it go away!
I dont claim to know too much about clutching but would like too. I do know these so-called clutch kits I have bought from highly respected company&#39;s over the years have made my sled slower and destroyed belts in 200 miles or less.
It boils down to either leave it stock or try try try on your own.

H.O.RIDER
05-31-2003, 04:35 PM
Snowmutt sets the record for the longest run-on sentence in history.

Mikadoo:

I dont profess to be the greatest clutch tuner on the planet but going to a lower finish angle to help stop overrev makes no sense to me. Do you mean over shift or overrev?

Mikadoo
05-31-2003, 06:25 PM
Originally posted by H.O.RIDER@May 31 2003, 03:35 PM


I dont profess to be the greatest clutch tuner on the planet but going to a lower finish angle to help stop overrev makes no sense to me. Do you mean over shift or overrev?
Is there a difference?

H.O.RIDER
05-31-2003, 06:44 PM
They are oppsosites.

When you overshift(or upshift to a ratio you cant pull) your RPM&#39;s drop as your motor is loaded too a point where it cant hold its revs. Just like trying to start out in 3rd gear in your car, you cant get the revs up.

When you overrev you are not loading the motor with a ratio that will keep its RPM&#39;s at their happy spot.

You mentioned you were going with a lower finish angle to stop the overrev. I would go with a higher finish angle or more weight in the primary(depending on the rest of the shift curve) if I was overrevving on the top end. Also. depending on when you start to overrev make sure your gearing is not too low.

Dynamo^Joe
06-01-2003, 11:04 AM
Quotes Paul_Aris:

Joe, What kind of belts do you use?

I personally use the stock belt that come from the factory. Regardless of what sled I am working on, I choose to play with what came on the sled.

I have always heard to run the OEM belts because that is what the clutch was set-up with.

The factory calibrates with that belt, so if you calibrate with a belt that has a different compound or angle, the it will throw your clutching off of "stock calibration"
Now notice I only say "throw off of stock calibration"...I never mentioned if this was beneficial or not.
I get a lot of emails from 800 owners saying they remove the stock 166 belt and install a 127 belt and they find this a beneficial move for them.

On my clutch kits, everyone who did not have the stock factory belt found that their rpms were high. Some as high as 9000 rpm on 440 cc sleds. I ask them what belt they have on, they tell me, I tell them to put back on a stock belt and everything is ok.

There are different manufacturing tolerances and compounds used. If I could run a Dayco Ultimax 2 or a Gates Extreme I could get them just over cost and save a bunch of money.

Hmm...I know you are interested in my S4X kit. I&#39;ll say this if you put on a new oem belt and calibrate the correct flyweight, you should get a whole season on one belt.

I would think it would be alright as long as the clutch was set-up to the belt used and you always use the same belt.

In my case you&#39;ll find that you will have to install a lot of flyweight to get the rpms down, then you will notice that the engine will be slow to flash to peak.

That would be if their tolerances were tight enough that you got a similar belt each time. Any thoughts?

Its the compound that makes the difference. You&#39;ll find that when you change to a different belt the rpms raise, then the compound is harder. If the rpms drop, the compound is softer.
Changing out an old oem belt to a new oem belt, you will find probably everytime that the rpms drop. The "surface" on the old belt becomes very hard over time.

Paul_Aris
06-01-2003, 11:28 AM
Sounds like a stock belt with the SX4 clutch kit is the way to go. This is my first Ski-Doo so I am not what an OEM belt costs. Do you know what most dealers sell them for. My Polaris my dealer alwasy wanted $70 or more but I new of a performance shop that sold them for around $55 plus shipping so I always went that route.

Dynamo^Joe
06-01-2003, 12:57 PM
Prices in Thunder Bay
The belt for the polaris Pro-x or the xcr&#39;s are $100 each.
The belt 8607 for the mxzx/rec is $47 bones....cheepy cheepy.

Try the stock belt and if you know someone who has a Dayco/gates or other...borrow it and try.

Do not....I repeat DO NOT use a Goodyear...
...unless you want the equivalent of a belt with sandpaper for belt surface...hahahah
Goodyear belts wreck clutches from the kevlar chord that is in the top layer.

...bad belts.... :angry:

Dynamo^Joe
06-01-2003, 11:44 PM
Joe,

Let us not forget that at high speeds or rather high shift ratio&#39;s the belt speed is up around 2600 ft-per minute. This by it&#39;t self creats alot of heat just from the centrifugal force trying to pull the belt up the sheave as well as the bending action the belt goes through.

I agree with you 100% but I won&#39;t let the numbers influence me on what I am searching for...which is to achieve the lowest temperature possible.
I have gone from 140 degrees "F" on the secondary down to 80 degrees "F". Temperatures measured on days that are 32 degrees or less outside.
What I as others have noticed is that there are 3 sheaves that are cool and one sheave that is hot.
I ask owners to touch all 4 sheaves and tell me which one is the hottest. It is always the fixed sheave on the engine. The sliding sheave on the primary and the secondary sheaves can be within 10 to 15 degrees difference, but usually there is 40-60 degrees difference between the fixed stub sheave and the other 3 sheaves. Why this is so, I have not the foggiest idea.

I let the data speak for itself. Over stock with a kit, a sled has increase of 10+ mph, backshift is great, upshift is improved, mileage is better by a 1/4 to 1/3 per trip. All was done with details that make the sheaves put the clamp down on the belt more than before.
I have done the calculations also with answer like you mention and for me they are very interesting.
But really, what can I do with these numbers? ...I dont know,

I have spent some pretty good time studying the effects of belt bending over the years and unfortunatly it is a flaw of the CVT drive.

I agree also 100%. I study belt drives for the non-destructive testing I do at work. I work with pretty well every style of belt drive there is, including CVT drive. From engineers, I get asked my opinion of my experiences with systems in the mill. I want to eliminate the flaw you mention and always recommend them to design using HTD. "Cog Belt/High Torque drive" I really do not like v-belt systems.

I quote SUPERTUNER here. The statement he makes is kind of disconnected in this conversation here, but it is connected of him pointing out the flaw you mention. You both mention "belt bending". The problems at the lowest speed and at the highest speed.


Quotes SUPERTUNER from AmSnow.com/forums
The reason I state this is because I am having a problem with understanding why 265 HP doesn&#39;t beat 248 easily. It should.
There still is 17 more HP that looks absolutely devastating on the dyno graph! In my opinion, I think
we are reaching the limit of "capable work" that the belts and clutches can do.
In other words...even with the best Hulings or Micro Reactor billet clutch there are still inefficiencies.
I have noticed a trend where the supposed BIG power engines run about the same as the lower but good engines.
There is (in my opinion) a "governor" somewhere and I think it is the clutch and belt.
I have personally built 265 HP engines and although they will tear the hinges off hell, everytime I left the starting line, I smelled belt smoke. We did try different clutches and wicked hard compund belts but there
was always that wiff of rubber from the belt.
I think we have pushed the limit of available "traction" (for lack of a better term) of a CVT drive and
belt driveline. 265 should be crushing 248.



Remember that the belt is also the connecting heat sink between the secondary and primary. Therefore when doing high speed testing don&#39;t always assume the heat is generated from just one clutch. Likewise if you have just done a 2 mile run and the clutches are the same temp don&#39;t assume the clutches are dialed perfect. The belt will eventually transfer the heat from the primary to the secondary and vise versa. This is often an overlooked situation

With this said then its still troubleshooting. Make a change, record the data, look at your numbers, make a decision. Tread further making more changes, record the data, look at your numbers, make a decision reduce the flaw to its smallest size.

Dynamo^Joe
06-03-2003, 12:19 AM
I think this is my last post on this forum.

Over on the performance clutching forum, Some guy asks about what to do to his sled to improve the performance.
Right away mxzwfo, clutchman and 800MXZ recommend a Goodwin clutch kit.
Nothing wrong with that at all.

I see this a lot on this forum.
Guy asks about enhancements....he gets recommended a brand kit from so and so....

I come on here mentioning of my kit and I get Censored!!!! My replies get deleted.

I see this as nothing but a kind of double standard.

Ok, so how about some guy other than me....like say a customer of mine happens to read this and says something about my kit...Should this person be censored too?

I have more passion than I can measure when it comes to clutching and I share almost any info I have freely...with or without asking. If I can squeeze something in that I make kits, I&#39;ll do it. Why not...Its Capitalism at its finest.

I would like to be told otherwise but I feel that I was censored.

Anyone can find me over at my home....amsnow.com forums.

Now to complete unfinished busines...
My reply to Mikadoo

#1 You say you dont know the difference between ramp profiles? I take it then you go with whatever is stock in the sled?

Yep! I work with stock ramp details and come up with a helix that works to what people want for their sled.
Plus, this keeps the cost down when people buy my kits. Hey, there&#39;s nothing better than a cheap clutch kit that rips a$ses. Like I mention in earlier pages...I don&#39;t like to just change parts. I like to make the parts work as best they can. This is learning.

#2 Yes the coated helix is from Doo&#39;s parts book and it better be "as advertized"! Reason going to try a lower finish angle is to help stop over-rev on top by loading the engine more. I have found in my limited clutch tuning abilities that for every degree you raise OR lower angles = 100 RPM&#39;s.

Erm...if you lower the angle, you will not load the engine. The rpms will start to raise.
1] You load the engine with a larger angle helix. ex: Going from a 40 to a 50. The rpms will go down.
2] You load the engine with flyweight to compensate for the rpms climbing or raised rpms.
What you might want to try is loading the engine with flyweight to bring the rpms down at high speed. You want to keep the angle low at high speeds, because you want the sheaves to clamp the belt harder. Just like GLH suggests to do in the previous reply.

#3 Going to try a stiffer spring on the high end to add more belt squeeze. Now you are saying it will be less belt squeeze?? Unless I read all your post wrong, you are now saying less pounds = more squeeze?

You will have to copy/paste that passage you say I mentioned. I just re-read what I typed and I cannot find this.

#3 Why do you want big pounds with your muched talked blue/white secondary spring?
Two things:
1] Clamp the belt harder than the stock secondary spring.
2] The blu/wht spring at full shift when the sheave is opened fully in degrees counterclockwise has more torsional force than the stock spring. Even when you set both springs at say 18 lbs pretension...at full open counterclockwise, the b/w has more torsion.

Are you saying less spring in the drive and more in the driven? This is the way I read you now.

No! I am just saying what I did. The only thing I say to do is make a change that is substantial that you can measure. So you are gonna measure the rpms, the mph, make a comment of your seat of the pants under acceleration, secondary temperature, pick a clicker that gives you the straightest shift regardless of rpm being high.
so you will take the data and know what to do. Your notes will tell you what to do. You know the theory.

I know adding-subtracting pin weight plays into getting the desired RPM&#39;s but in most cases if you get the desired RPM&#39;s on top you lose on the bottom.

I agree with you about adding/subt...I disagree with you "most cases...rpms on top, you lose bottom"
Explain "lose bottom" please.

Sure, change clicker positions and usually get back to square one, so where is the line where it will finally get a straight RPM all thru the run?

You&#39;ll find it. Choose a position and stay with it.

I can achieve a desired RPM for the first few feet then the over-rev begins. Clutch heat, He11 yes! Make it go away!

Must start somewhere. Change secondary spring to a stiffer spring. Rpms go up?...so!...measure temperature of secondary. When you find the temps go down, your mind will start to race because you&#39;ll be on your way.

I dont claim to know too much about clutching but would like too. I do know these so-called clutch kits I have bought from highly respected company&#39;s over the years have made my sled slower and destroyed belts in 200 miles or less. It boils down to either leave it stock or try try try on your own.

I cannot say enough about notes. You do not make notes...you learn nothing. You make notes, you will become a savvy tuner in no time. You mention try try try...Thats what I did. My kits rip new a$ses.

H.O.RIDER
06-03-2003, 07:47 AM
This forum is in jeopardy of losing another great source of information because of a constitution that is for far out of date it must have been written befor computers were invented. Lets stand together and let the forum managers understand why we come to this forum. IT IS A SOURCE OF INFORMATION!!!!!!

Every damm time soneone mentions another site or that they can sell you something to make your sled go faster DONT DELETE THEIR POST!!!!


I enjoy this forum but the censorship in unreal. Recently I posted an ad for a snowmobile I would like to buy. I posted it where In the forum where I wanted it but someone in their infinite wisdom had to move it to suit there needs. At the same time a forum moderator posts he is looking for the same sled and will pay $5 more than I. (joking or not its the same double standard Joe is talking about)

I am sure this post will be deleted befor many can read it but these are my opinions and I hope you will all express yous so we can keep Joe and others like him around.

idooski
06-03-2003, 08:50 AM
Dynamoe^Joe don&#39;t go. As one of the moderators of the new tech section, I&#39;m personally inviting you to come on over to the tech section. We are going to be much more lenient (sp) about guys promoting thier products there. As long as the discussion explains how the product works and how it will benefit the user, which your discussions obviously do, we welcome the input. In fact, I would like ask Rocketman if he would please move this whole discussion over to the tech section to be continued.

Think about it, buddy. None of us want to see you go. All of us want to learn what you already know and have to teach. But if you want to push your product a little, you need to do it in the Tech Section.

Mikadoo
06-03-2003, 04:39 PM
Joe, please dont get to upset I&#39;am sure we can work this out.

As I told you before, you are a wealth of info. and I feel it would be a great loss to everyone if you were gone.

Ok, back to a couple of questions you wanted cleared up.
1 What I meant by going to a lower "finish" angle on the helix to stop over-rev was, by doing so, the smaller angle is going to grip the belt harder thus stopping slippage and lower RPM&#39;s and also produce less heat. Right?

2 The pin weight deal is, everytime I get what I want for RPM&#39;s on top the bottom is way down and out of the power. Is this where you would change to a steeper angle to start off with and leave the finish angle the same?
I&#39;am going to chill for a while on this subject and go over your past notes and see if I can get a better understanding of this.
Thanks man, and hang in there!

Dynamo^Joe
06-03-2003, 10:48 PM
I have to finish the story I set out with....

***DAY 3 MONDAY***

Ok so we know what happened yesterday and have a good plan for today.
In the evening we were talking about going up a tooth in the gear. 21/43 is original, and how about 22/43. Reasoning is that Rocket man is getting about 2mph on top end compared to me. Maybe also with that gear we could keep the midrange stronger and thus go farther in feet without the engine dropping off like it does.

We did something I really do NOT like to do. Rad Chad went down and changed my gear to 22 before we even made a run. I kind of had a chuckle as I wanted to make a few shakedown runs with the new CPC-Blue/White secondary spring and [47-41 Dalton Helix]. "Oh Well” Heh, we will just play with the cards I was dealt with. I went out and did a run around the lake getting on and off the fuel. "Jazzing it” Ok now were warmed up...HAMMER DOWN!!! WOW, 8800 rpms. WOO HOO. Good air to make overrev this morning. Were up 100 rpms from yesterday evening.

I come into shore. Rad Chad said."We going to add some screws?" Yep, you bet.
After each screw I went for a few runs down the 3/10th mile.
1 Screw [0.8 grams] - 8800 rpm thru top end of midrange, then engine pulls down to 8700..maybe 8650 - 83 mph.
2 Screws [1.6 grams] - 8700+rpm thru top end of midrange, then engine pulls down to 8600..and $change - 84mph.
3 Screws [2.5 grams]- 8600 rpm thru top end of midrange, then engine pulls down to 8400..and $change - 85mph.
The 4th change was a screw that weighed [2.1 grams]. 8600+ rpm thru top end of midrange, then engine pulls down to 8400-8500. - 86mph "Hard to tell"

WOO HOO! I found the honey spot of my engine "I do believe" Looks like the power is real strong lets just say between 8550 and 8650 rpm.
We did back to back runs with that and got an average of 85mph.

THE PROBLEM!!!
That 8400+ "Tach rpm" is a problem. Lets look at this now. Over all the testing we did, I pulled of the steaming mph @8600+ rpms. I still go across at 85mph with pulling down to 8400-8500 rpms. My midrange is screEEEAAAMINNnnn. Holy CRAP!

I knew what was going to happen already if I changed the clicker, buuuut I figured "what the heck" and let&#39;s prove what will happen.
Clicker to 5 = 8800+ rpms. Low mph
Clicker to 3 = DOG! "Bow wow!!" HAHA.I&#39;&#39;m not even going to say how low I was revving.

So I continued to race against myself with the radar gun. I ended up changing my pretension with the hopes that I could prolong the engine at 8600 ~ thereabouts before pulling down.
I went in to shore with 17lbs and spent a few minutes changing holes to find 18lbs. AHH, TRA secondary are BEAUTY for getting 1 to 2 lbs increments. I do make my P-85 and ACat secondary to have the same capacity by drilling those adjusting holes in 2 other locations.

Out on the radar again with 18lbs I consistently got 85 mph...Back 2 back. It seemed that the engine DID want to stay at 8600+ a little longer in feet down the track before pulling down to 8450-8500.

***END OF DAY***
Ok well now its DRAG RACE time. In that evening Shooter, Rockeman and I dragged about 10 times.
Shooters would hookup hard all the time with little spin and get a holeshot a bit on Rocketman and I, and then we would reel Shooter in and pass him. Every single time.
Rocket man would come out strong on the big end and pass me by the radar trap about 2-3+mph faster.
HAHA, I was PISSED, once Shooter pulled across right in front of me and I thought "great, I&#39;m getting all his snow dust” He pulled across enough that I kept a straight line to go by him. I would reel him in and pass him.
The second race he pulled across me again. HAHAHAHAHA...Ize just thinking..."Ooh well, I&#39;&#39;ll just have to pull out and pass him" La la laa la laa ...scuze me, coming thru.
does anyone know what its like to say that against another similar cc sled?

rrreeeEEEEEOOOWWWWWwwww...*WAVING BUH-BYE* "SeEyA sHoOtEr” Oh I had to say that out loud under my helmet. Ohh you don&#39;t know how much fun that was to SLAY in the midrange like that.

Rocket man with his 2001 Pro-X 440 basically just adjusted his pretension for the day and messed around with the THUNDERSHIFT flyweights. Those babies are BEAUTZ!
Rocket man basically kept the same weight with in a gram and moved around the composites [washers/bolts] He was looking for more engine flash thru the clutches.

***OK Day is over***
Time to plan for tomorrow [Tuesday] over a few beers & food.

So this day we accomplished:
1] GOOD JETTING. Piston wash O.K.
2] SHIFT PATTERN. Got the sled to pull fairly straight all the way to top end while yet over-revving, but straight rpms. Found the honey spot of pretension that worked the best.
3] FOUND PROPER WEIGHT. Added 2.1 grams to get engine down and pull like a mad wh0re on payday.
3] FOUND BEST RPM TO RUN AT ON TACH = 8600+ and change.
4] CONSISTENT MPH at about 85. We increased 4 mph average from yesterday
5] GEAR CHANGE worked as we made it work.

Problems We Still Have...
1] Revs right on 8600 "tach rpm" thru midrange to top end, then pulls down a hundred rpm or so.
2] Mph is still low...were geared for 93mph and we&#39;re only doing 86 topped out.

Planning for Tuesday...
1] Raise rpms at the big end.
a) Change Primary spring to higher final tension?
Or
b) Change cam from 47-41 to what? Cam with a lower final number?

Reasoning...Everything we planned on helped to change rpms to pull hard. Everything we thought that wouldn&#39;&#39;t work we predicted what the effect would be.
Only things left is to change primary spring or cam.

Well, I&#39;ll tell you all this right now. Every damn Ski-Doo I have drove has done what people call [over shift] what a cheesy term, but it&#39;ll do for now. You run the sled out to the big end and dammed almost all of em are mph low compared to other brands.
Best suspicion is that the arms are weighted too much on the end and when the primary is closed [full shift] the arms want to stay out there and not backshift. The primary pushes very hard.
Why?
The secondary is "torque sensitive” If the secondary cannot resist the force "Push" from the engine, the secondary will stay opened and not backshift...it will not compensate...I really like that word in this case..."Compensate" and resist the engine so the engine will fall off or lose rpm.
Another thought on top end loss with Bombers is the secondary spring. Heat tells great stories. I removed the oem secondary spring and installed one that has more compressive force at rest and full open. The spring pushes the sheaves together quite nicely gripping the belt hard. Beige spring...My opinion, not enough.
Another thought is that it takes a ton of pretension waaaay out there at full open secondary. The beige does not rise enough in rate under tension at full shift to come up with a force to help the sheaves grip the belt.

So now I have a [for lack of better numbers] 380 lb final tension spring in the primary.
To keep the rpms from falling out there at peak mph&#39;s; Why would I want to put a spring in that has a finish force of say...390 or 400 or 410?
The arguement could be that the primary is pushing too hard at peak mph. [Im losing rpms] The primary spring with a higher final force in lbs would resist the push of the flyweight and keep the engine up there, right?!!

Lets think now that if you put more spring force in the primary clutch to resist the flyweight to increase rpms and you will take away from the capacity the secondary can do.
The engine is pulling down. The secondary cannot resist the push from the primary thus keeping the rpms straight to top speed.
Im gonna leave the primary push like it is and get the secondary to grip the belt better.

SO...Knowing the details that the secondary is in right now with that spring and pretension...I get the straightest shift I can. The backshift in the snow over at shore is very nice indeed.
CAM ANGLE under good belt deflection will in this case change rpms at top speed.
...This is the route I will go.

If 41 degree is still pulling my engine down way out there by 100+ rpm, I need a finish angle that is lower.
Theory goes...Lower cam number, higher rpm.
So tomorrow a 47-37 is going in and were going to shoot for that 100+ rpm.

Tuesday results almost made me wet my pants.

mxzadr800
06-04-2003, 05:54 PM
Ya can&#39;t leave a man hanging like that JOE :p

6
06-04-2003, 05:57 PM
Moved by request to tech forum:

clutchman
06-04-2003, 10:33 PM
have you even tried a straight 50 helix???

Dynamo^Joe
06-05-2003, 05:33 AM
Originally posted by clutchman@Jun 4 2003, 09:33 PM
have you even tried a straight 50 helix???
Yes...I have tried straight:
32, 37, 40, 41, 42, 44, 45, 46, 47, 48, 50, 52, 54.

Progressive
54/48 54/46, 53/47, 50/47, 50/44, 50/40, 50/37, 48/44, 48/42, 48/40, 47/41, 47/37

2 custom prog helix that are larger start than 54, and 9 progressive that I had custom made right down to finish angles of.....well that&#39;s for me to know. lol

Dynamo^Joe
06-05-2003, 10:25 PM
Mikadoo* Ok, back to a couple of questions you wanted cleared up.
1 What I meant by going to a lower "finish" angle on the helix to stop over-rev was, by doing so, the smaller angle is going to grip the belt harder thus stopping slippage and lower RPM&#39;s and also produce less heat. Right?

Yeah, we want belt grip for sure. Hmm....well yeah theory wise getting the sheaves to grip the belt will load the engine harder because you are now making the belt pull the secondary more efficiently which pulls the sled faster/quicker....I did not say how to do it here though.

There are a few times where your results may not match the theories. Please don&#39;t think for a second im trying to sound like a knowitall, I just wanna save you a lot of $$$ and gain an "easy" experience here from what I typed in the Clutching weekend notes.

You look at what I did, the first thing I got rid of was the heat. I did it by changing the spring to we&#39;ll say a Stiffer spring.
Ok I got an over rev....GREAT!!! this means that the spring is doing its job by pushing the sheaves together harder.
Temperature is down.
Find the clicker number that gives you straightest rpms right to top end. Who cares if they are high....find straight shift.
Go run it.
Problem...overrev. Solution, compensate for high r&#39;s and add some flyweight.
Go run it.
Need more weight?...add more...
Add more so that your engine rpms fall below what you want.
Now you look at your helix...regardless if its straight or progressive just what number are you dealing with at high speeds. what number does your button or roller end up at?
Ok so the r&#39;s fall off, then you need a lower helix angle at the full shift to resist the push from the primary.

Work with a spring to get the heat out.
Find a straght shift with clicker.
Add flyweight to pull engine back down.
Add flyweight to make engine fall off peak.
Try a different pretension.
Make another run and check rpms.
Compensate with lower angle helix at full shift for falling rpms.

I done this step by step breakdown with dozens of sleds over the years, in person and advice via tuning by email/phone, whether it be a Doo, Cat or Pol. It works and its quick quality learning. I just ask you to keep saying "compensate" to yourself over and over when you record a number that you don&#39;t like.

Believe in the excersize you just performed. You can always know the theory but when you now have an experience you will learn quickly what one part of the system has more of an influence over another part. You can make a quality decision on what to compensate for and predict an outcome better. And this is the best part...No one can tell you different from your exersize. If you get in an arguement with someone, you can stop them in their tracks if you remember your notes.

2] The pin weight deal is, everytime I get what I want for RPM&#39;s on top the bottom is way down and out of the power. Is this where you would change to a steeper angle to start off with and leave the finish angle the same?

Explain "down and out of the power" please. Fallacies like "down and out of the power" really leave a person open to interpretation. Someone may think that you are below your engine peak, or that your engine is not quick enough to flash to peak, or that you are underrevving momentarily.
Explain what the sled is doing.

I&#39;am going to chill for a while on this subject and go over your past notes and see if I can get a better understanding of this.

You will, don&#39;t worry. You are asking the right questions. I just hope I do not provide bad answers.

machz69
06-06-2003, 10:38 AM
hey joe.. weve herd how well your set ups work and like ten miles of theory on the subject but what sled do you run? where do you run it? and what do you run ? do you drag race? do you speed run? do you radar ? it would seem you have tried a ton of clutching i would like to know where you are and mabe we could hook up and do some running.... the proof is in the pudding.. :sly: ;)

Dynamo^Joe
06-06-2003, 12:50 PM
I run a 2000 mxzx 440.
I also have a 97 440.
I just bought a 440 REV.

I trail ride on the pipeline from Thunder Bay all the way to Geraldton/Longlac ont.
I mostly run from Nipigon to Beardmore.
I put on about 2000 miles per season and I bet last winter I only put 8 miles on a lake.
All of my friends have mxzx/rev/pro-x sleds. All 7 are 440&#39;s and one 600 engine in an 03 Pro-X race chassis.
I am an extreme x-county rider. I run on trails that are so rough that with revalved Sno-X valved suspensions we can only run about 60-70mph. Rarely over 80.
I do all my clutching for sleds now in this environment. Clutch sleds for the harshest suspension loading and engine demand conditions. Clutching in this environment has forced me to come up with helix&#39;s that are out of the "box" or "norm" that people frequently use. 99% of you guys would not believe the angles.

I snow drag...sometimes.
I do not do speed runs. I do not do radar runs.
At one time or another I have made efforts in all the disciplines.
I had shares in a team of drag sleds [3] and was the clutch guy for 4 years.
92-97 I was on a watercross team. I learned more about clutching in one season there than I did in 5 years of any other racing Ive done.
I did clutching for a factory ACat rider in the x-country/sno-x circuit 99-01 seasons.
I spent time testing clutching at the Cat factory and have been invited/participated to do testing with Ski-Doo team X & friends in sno cross.

I would ride with anyone. But really, we dont care for anyone riding with us unless they have a race sled like a 440 of Doo/Pol or Cat. Any other sled is too slow, especially larger cc sleds. we have to wait a lot and well, guys with sport sleds will just bend rails and shock shafts.
...sorry that sounds kinda arrogant, but we "me" are addicted to this type of riding. When you break a rhythm and have to stop, it takes too long to get back into the groove again. The more times you have to stop, each time it takes longer to get going again. I like to gogogogogogogogogogogo and only take a rest once an hour, frequently look back and check your partner behind you and drive like toggle switch...On....Off

machz69
06-06-2003, 05:01 PM
hey the cat factory and bomb x has been added since the last post........lol. but anyhow its kindda to my point. the type of set ups you have been saying dosnt apply to me and was wondering on how you thought it would work better but now i see. with 440`s it might be a little different. i too have done some x cross clutching and have set some up to always be first in the corners. but that type of racing realy does not come down to clutching so much as it does rider. see around my erea clutching for up to say 80m.p.h. will not help you much. but you had me a little baffled? you had said a fiew times about testing with a radar gun but you dont radar run? i have done some testing with a radar gun also but found out pretty fast that unless your just running for speed your gonna get killed .....lol.. (drags). how old are you?... dont take this as some sort of personal attack on you im just currious....lol.. now i see why you want to get into the multi angle cams. dont you find that a better rider for that sort of thing will out do any type of clutching you could come up with. anyhow just babbling along here..lol... you will have to come up this way to do some testing where a 1/4 mile straight away is a sort one ....hehehe

Dynamo^Joe
06-06-2003, 09:08 PM
Setups that I make for friends and the ones I sell are for trail riding, drag race and speed runs and all with one helix, believe it or not.
I have back up helix for different compressions though.
Example:
The 440 has a range of compression from 115 lbs to 165 lbs with low compression head.
The 440 has a range of compression from 130 lbs to 195 lbs with high compression head.
The 800 has a range of compression from 125 lbs to 155 lbs in stock form.
...I have measured these myself.

The reason for different values is because of cylinder fitness. Piston to wall clearance, Rave spring position, Rave valve to cylinder clearance, basegasket thickness, reed petal seal and petal lock tab position.

I will pull numbers out of the air here to promote an example...
A 440 with 115 lbs to 145 lbs I could use a 50-45 helix.
A 440 with 150 lbs to 170 lbs I could use a 53-45 helix.
An 800 with 125 lbs to 135 lbs I could use a 48-44 helix.
An 800 with 140 lbs to 155 lbs I could use a 52-44 helix.
The sled with more compression also can push more flyweight and/or one lower clicker position.
I dont care what anyone says if they do not believe this, my notes and feedback from nearly 70 sled owners prove this all the time.

My clutching is for full range right to top end. You read in the Clutching Weekend that my sled was at 79-80 mph when I start? Well my sled now time after time goes 93mph...from 79 in the same spot on the same lake. I have 1.25 track and suspension is let out right to the max travel less 3/8". I am geared for 89 @ 1:1. My pal on his 99 can pull of 94mph every single run.

About the radar thingy...My pal Rocketman has a radar. This is what we use. When we go testing, it comes along with us all the time.
I am 34 yrs. 35 in Oct. I know this is not personal attack from you. I have big mouth and you just want to know some stuff, so this is great...no? HAHAHA.

The jist of why I like multi angle helix. This is out of my manual I supply with product:
The cam uses a blend of angles that are used in speed runs and drag racing.
When you look at the cam, you can see it starts very steep and smooth out to a low angle.
You know that: 1] low angles produce great backshift 2] Large angles produce great upshift
The cam provides an angle that the sled "Needs" at the speed it is going.
You punch the fuel, it upshifts and accelerates hard...let off the fuel the clutches backshift quickly, you punch the fuel again, you upshift and accelerate hard.
The clutches have a fantastic ability to grip the belt all the way to and past 1:1 ratio using wide spread multi angle.
The low temperature is the clutches telling the tuner that the system is very efficient.
I get 20%+ into overdrive with it on river runs @ 93mph.

Ok that being said...
*Do you need a 37 angle to start? No, probably not! Mmm, 50 say would be more like it right?
*Do you need a 50 or 37 in the midrange speeds?...probably not. Something more optimal would be in the 40-46 angle range for midrange acceleration and backshift.
*Do you need 50 to HOLD a high mph? No, it probably wont happen with a 50. Secondary temperature will prove this.
*So how about instead of a 50 at top end you could use a 37? Yeah, probably so. Do guys who do speed runs use a 50?...probably not many who are successful.
So look what you end up with. 50 to push you outta the hole hard and blend to a lower angle to help you maintain a hard high top end.

Back to what you talk about sno-x. I only make sno-x setup by request and that is it. I do use a multiangle helix but the spread is not that great in degrees. I had a very humbling and unbelievable learning experience when I was in Thompson MB doing clutching with Team Ski-Doo and company.
Cannot get high mph with my sno-x setup. Helix is too big and other details. But Sno-x setup are pure monster 0-40 mph holeshot and midrange is used very little unless the track is fast with high speed locations.

Cya L8R

I. M. Abigmouth

Mikadoo
06-07-2003, 02:15 PM
Originally posted by Dynamo^Joe@Jun 5 2003, 09:25 PM


Explain "down and out of the power" please. Fallacies like "down and out of the power" really leave a person open to interpretation. Someone may think that you are below your engine peak, or that your engine is not quick enough to flash to peak, or that you are underrevving momentarily.
Explain what the sled is doing.


Joe, you pretty much answered it yourself but here is how I can explain it.
You pin the throttle and the tach hits say 8000 but you need 8500 to be in "full power". Ok, so a cure for that could be to go up a click or two or lighten the pins a little?
So now we got the 8500 we want but the damm over-rev is still there going to 8800+.
Just trying to find the magic spot where 8500 is 8500 all the time.

Dynamo^Joe
06-08-2003, 09:44 AM
Joe, you pretty much answered it yourself but here is how I can explain it.
You pin the throttle and the tach hits say 8000 but you need 8500 to be in "full power". Ok, so a cure for that could be to go up a click or two or lighten the pins a little?
So now we got the 8500 we want but the damm over-rev is still there going to 8800+.
Just trying to find the magic spot where 8500 is 8500 all the time.

I agree with you that there is probably two issues that must be dealt with. Im going to be reserved about the clicker/lighten pins thingy for a little bit.

Issue 1: You pin the throttle and the tach hits say 8000 but you need 8500 to be in "full power".
Issue 2: ...we got the 8500 we want but the damm over-rev is still there going to 8800+

Im a fanatic of alignment and belt deflection. Can we please perform a test first just to rule out this detail so we never have to think of it again? :D
I&#39;ll tear a page out of my clutch kit manuals here. In the paragraphs, i&#39;ll highlight what I want to know from you. Its not surprising how many people give me feedback of the performance improvement when they start to do this procedure.
Dude...sorry for being long winded, but im hoping others copy this article and keep it for good reference. :D

I&#39;ll get back to issue two later on....

When I work on Stock or Modified sleds, I take care of details in this order....

1] Secondary Belt Height:
I like to have the chord of the belt showing on the outer dia of the secondary.
*Why?* Well, if you look at the actual belt travel...The distance the belt
travels towards the center from the clutch being closed to fully open, the
belt travels only 1.25 inches approximately.
So to think of it, if you have the capacity to go from 0mph to 100mph...The
belt only travels that range of 1.25" in 100mph at 1:1 ratio.
So, would you not think that you would rather have approx 2mm of belt
showing on secondary? 2mm=.080"
Now you have ~1.30" to 1.33" of travel instead of ~1.25"

Benefits are;
1] That is 10% more belt movement from the engagement to top end.
2] Extra time the belt spends in the lowest ratio possible in the first 100
feet when you gas on it.

2] Best Belt Deflection = Track Movement:
Lift the sled onto track stand.
Start the sled.
Warm the engine up.
Burp the engine to turn the track.
Get the track nice and limber.
Get the "cold" outta the track and loosen it up.

When the sled is on a track stand and the engine started and idling; The
track should:
1]Creep slowly
or
2]Turn with jerking movements
or
3] Track is still, but you are able to move it with by pinching a paddle with index finger and
thumb then pull the track around fairly easy.

You should now already have proper belt height on secondary. You must get
the right belt deflection.
If you cannot get this kind of deflection...get longer Drive belt.
Be satisfied with that belt then. When buying a belt, take a "Seamstress" measure tape with you and measure the belts.
If a parts person gives you a hard time over it...Tell him "Go to hell, It&#39;s your money!"

The results are very important. You will be quite happy in the end. Your sled will never bog with these conditions.

Umm....You have found that your track moves on the stand at idle....Great.
As long as your track moves or needs just a bit of coaxing with two
fingers....You have great belt deflection.

Effects of Improper Belt deflection:
Too TIGHT of deflection:
1]Burns the belt cogs when sitting near engagement.
2]Increases Torque at holeshot, but Hi-end mph is down.

Too LOOSE of deflection:
1]Bad holeshot, possibly bog.
2]Slow In midrange
3]Possible higher mph in midrange only if engine does not pull off peak[Old
speed run trick]
4]Engine pulls down out near big end.
Note: High engagement will eliminate bog, but acceleration deteriorates
quickly by 2/3 track distance then 90% of time, engine falls low of peak
rpm way out there.

Belt clearance:
Prefer to have .025" to .030" on the primary.
Tight belt clearance lets the tuner have better control of engine flashing thru the clutches.
Tight is good for belts and will let them last a long "consistant" life.
Have to watch that Bombardier made a whole batch of bad belts that went to the public in 2001 and 02. There was many Bomber drive belt number 414 8607 that were only 1-1/4" new off of the shelf.
The belts were brand new and smaller in width than a wore out [year 2000] 8607 belt.
I went to a few Ski-Doo dealers and all they had were brand new 8607 belts that were 1.25"
The belt is supposed to be 1-3/8". This left clearance of .080" on the primary.
What happens is the relative position of the TRA arm is farther per mph as the primary shifts, so the rpms will be lower than normal.
This produces an off peak rpm. The thin belt will create problems.
Take your measure tape to the dealer when you buy a belt and let them know if they have any narrow belts. It says right in every Doo manual how wide the belt is supposed to be.

PLEASE DO THIS BELT DEFLECTION/HEIGHT PROCEDURE.


Mikadoo...What is your engine engaging at?...what rpm?

Mikadoo
06-08-2003, 10:14 AM
Engaging @ 4600, this is with a 200/380 spring.

Dynamo^Joe
06-08-2003, 06:20 PM
Really I don&#39;t have too much to say about the overrev going up to 8800.
I mean I can blame it on the secondary spring for the amount of heat right?
I can blame it on the secondary spring for being too stiff in the full shift causing an overrev, but you say there is a lot of heat, so for me Im sticking with the latter blame.
I dont really know what else to think when you say "heat" is still there. It really limits me to other issues I can think of.
This sled has a 280 ramp, right? The only other thing I can think of is that the ramp is too thick and causes the TRA arm to exert less push from the primary to the secondary as the speed increases.
Frig...I dunno.

Getting back to what you say about clicker and flyweight removal. Not sure that a change as such will render much to measure. You know, thee old effect of weight/clicker is more effective at higher shift ratios..square of speed...blah blah blah...

????....Don&#39;t think im too much help here. sorry!

machz69
06-09-2003, 11:13 AM
yeah but mikadoo you wont be able to hit 8500 then shift out to 8500. you should hiot say 82-8300 then full shift out to the 8500. what is it your trying to do? is this for drags ? or just trail?

Krusty
06-09-2003, 12:42 PM
What belt are you running? A Bomby gold, Ultimax or Gates will cause over rev. 067 works well.

Mikadoo
06-09-2003, 04:12 PM
Drags-trails whats the difference? When I pin that puppy I want instance R&#39;s, no more no less! My buddy&#39;s MachZ hits 8000 instantly and no more but doesn&#39;t run all that good. Another buddy with a 600 reneagade hits 8000 and no more.
Why is it so damm difficult to get a set amount of RPM on top and no more without killing the lower RPM?
I run a 066 belt. I found the gold belt is WAY to hard, great for low H.P. sleds that want to never buy a belt again........

Krusty
06-10-2003, 01:09 AM
My bad. Kinda hard to get an 067 on a CK3.

machz69
06-10-2003, 08:27 AM
well my machz will hit 8500 then pull back to 8300 then climb back up to 8600 so this is why im asking . you will hit 8500 in a drag 660-750 then it should pull down to 8300-8400 at say 1500feet then climb back up to 8600. when you say whats the difference ...well there is a huge difference. when you say it hits 8500 and stays there that tells me you have a problem. your clutchs are not shifting. if you mark your clutchs and then take a fiew runs and see if they are clean. you should be able to hear the shifts. not from on the sled but if you let a buddy take it and you stand back you should here it shift 3 times. if it does sound like one shift then your on the wrong track.

Mikadoo
06-10-2003, 04:04 PM
Here it SHIFT! Come on! Where&#39;s my waders? lol.
I do mark the clutches and they get wiped clean everytime. Dropping a couple hundred R&#39;s would be fine with me but dropping R&#39;s NEVER happens to me.
I will figure it out next winter, just going to take a lot of test time.
My buddy knows a welder that has a lazer heat temp gun, this will be a big help.

Glad the farmer next door put his field back to beans, makes a great test strip.

H20XER
06-10-2003, 05:14 PM
Back the spring in the driven off by 1 notch.. or if you do not want to lose the back shift go with a lesser of a deg cam..

machz69
06-10-2003, 07:33 PM
lol.....i knew you would say that but you realy can hear it shift... ill try to find the video of my sled in pro stock and on it you can actualy hear it shift. its pretty clear because it had open chamber pipes. but like i said stay back at the line and listen you will hear it if not if it sounds like all one long sound then your not shifting.

Dynamo^Joe
06-10-2003, 11:47 PM
***DAY 4 TUESDAY***

So yesterday we found what weight I like to run in the primary.
Sled seems to really turn on the mph thru the midrange at around 8600 rpm +.
Found what clicker we like to run on the lake. [Position 4]
Got 86mph run once...got 85 mph runs back to back.
Found good pretension at 18 lbs.
Gearing up from 21/43 to 22/43 was beneficial on lake.
Found that the engine still pulled down a hundred rpm or two out past the radar.

Today about the only change I have left is to take out the 47/41 Cam and install the 47/37.
First I went out and did a few shakdown runs around the lake. Got the sled nice and limber, engine warm...etc.
Came back to shore and went to the 47/37 cam.
Found the right pretension setting @ 18 lbs.
Jetting was ok
rpms held steady at 8600 thereabouts.

Rocketman with his Pro-X made a few changes to his Thundershift weights. His midrange was still lacking in the bottom 1/2, but his big end of the midrange after about 60mph was real strong, thus still reeling me in and passing me when I was topped out the day before.

With the 47/37 installed, I did some runs by myself to see how far in feet the engine would stay up at 8600. Well as predicted the engine stayed up in rpm longer in feet and my midrange was even stronger. WOO HOO...89mph on the box. YEAH!!!
Me keeping going past the radar box, I would just stare at the tach going across the lake.
Watching it the needle would stay around 8600+ and then several hundred yards past my old mark from yesterday, the engine did start to pull down again. This time not to 8400, but from 8600 & change down to 8500. Ok, an improvement of 100 rpm. I can live with that being that I got another 3+ mph.
85 to 89 mph I believe is damn impressive for a lil ol 440 with a 1.25" track.

So really my only recollection on this is that the cam must have helped out by resisting the engine falling off its peak "longer in feet" going down the track.

Ok, race time. Rocketman and I raced a total of 16 times. Shooter raced with us a total of 7 times. Rehab raced with us 5 times.
Each time on new snow [as best we could find] My midrange was very strong. I could walk away from Shooter and Rehab no problem. Rocketman was tougher, but to the radar box about 1600+ feet down the track, I got them all thru the low end of the midrange thru to the top end...every race. If we kept going to 3500 feet plus, Rocketman would go by me by about another 2mph. Yes his playing with his sled he really got it to turn on in the big end at wide open with about 91-92 mph...back to back runs. Rocketman&#39;&#39;s upper end of the midrange is once again stronger than mine, but it takes a long time to reel in and pass this day.

Yeah I&#39;m damn happy about the way my sled runs and the way Rocketman&#39;s runs.
I believe that I will probably go back to the 21 gear instead of running the 22 for the trails I am used to driving on. Rare is it that you can get up to over 80mph and sustain it safely without having to brake for a sharp corner or the bumps are just too damn big to go near that fast.

I have a killer setup for snow drags. My 0 - 660 foot is awesome and get some suspension tuning in there.....watch out. :sly:

Problem still I would like to figure out a cure.
I am still pulling down that 100 rpm waaaaaaay out there around 89 mph.
What to do?...
Change primary spring?
Cam down again to a 47-3X?
Take out setscrew[s] to get r&#39;s back up?

I believe that I am gonna try a primary spring. Ahh, it is against kinda what we been trying to follow here but, what the heck. Its only $25 buck compared to $120 for a cam eh.

Oh, before this weekend all started, I did remove the stock Pink White 230-380 primary spring.
I installed a RED Primary spring that is 230-410. Heh heh...This is the spring I did all my testing with.
I am gonna try to get that 100rpm back...I mean.."ITS MINE DAMMIT" LOL

So in the end here...Lets summarize the changes.

Stock
Engine 8500-8600 rpm.
Primary Pi/Whi spring 230-380
Original flyweights.
Clickers [Pos #4]

Secondary:
Beige SkiDoo spring.
18 lbs pretension.
Straight 44 Cam

Gearing:
21/43

Results...79 to 81 mph.

New Changes:
Engine 8600 rpm +
Primary Red spring 230-410
Added 2.1 grams to flyweights.
Clickers [Pos #4]

Secondary:
CPC - Blu/Wht from DALTON
18 lbs Pretension
DALTON - 47/37 Cam

Gearing:
22/43
Results...88-89 mph, back to back.

Things I wanna change in the future...
1] Go back to the 21 gear.
2] Try other higher final tension springs...play with flyweights.

Since this NEW YEARS DAY...
Rocketman and I with the help of Rad Chad have got another 99-440 zx to go about the same as mine. This 99-zx has a bit of a traction issue though, other than that, very similar results. Hamrhead [owner] is quite pleased.
Rocketman has lost the top end mph of 91-92 with his sled, but his midrange is pretty well dead even with mine. He has been playing with those Thundershift weights. heh heh
We race and it is almost like our sleds are joined together thru midrange to top end. WOO HOO!!! Who cares about that 2 mph...The midrange in that Pro-X is killer now.

There have been 5 upgrades since this exersize back in 2001 and the results are now 93mph consistant on the same run. Not so bad taking a 440 with a 1.25" track going from 79 to 93mph.

I found something out about Shooter&#39;s sled last season 2002. Somebody slipped out some information about that sled and it all come to light why none of us could ever beat it when "We" were in stock clutching. :0:

...many thanks to Rad Chad and Shooter for these details which they unwillingly divulged. :sly: :blahblah:

b.b. later to tell....

Krusty
06-11-2003, 12:43 AM
Joe, when you say you added 2.1 grams of wieght, was that per arm or total? Just curious.

Dynamo^Joe
06-11-2003, 05:19 AM
Originally posted by Krusty@Jun 10 2003, 11:43 PM
Joe, when you say you added 2.1 grams of wieght, was that per arm or total? Just curious.
Yep... A 1/2" setscrew to each arm to make a total weight of approx 12.2 grams pin weight.

machz69
06-11-2003, 10:34 AM
joe is your secondary splinned? or keyway? if it is splinned you should try to get your hands on an rer secondary they realy work well. just to try. i have tried a standard secondary on my sled and it did not work near as well. what ramps r you running? im guessing your next spring will be a blue it will be a little more off the line

Dynamo^Joe
06-11-2003, 12:20 PM
Yes, the race sled I have is splined.
Do you mean the RER secondary with the HPV Formula helix?....or do you mean the RER VSA secondary?

Well, its gonna be pretty hard to get better than what I have. I tried all winter with several other helix and spring combinations. Logged 1200 miles trying to do this against another mxzx and two rev 440&#39;s.
Im thru with trying to better my clutch kit for the 440. It plain outright RAWKS! I have 3 helix&#39;s for the different compressions the 440&#39;s seem to have.
All start with different angles, but finish at the exact same angle.

I have gone thru a few more primary springs already. Last season I chose to stick with one which is in the kit now.

I ended up devoting my time to the 800 kit for the rest of the winter.

machz69
06-11-2003, 01:01 PM
the rer with hpv27 i didnt know there was another one.... yeah but it realy does work much better then the standard clutch. you could actualy run shallower cams. such as say with the machz the standard machz runs a 53-44 with the beige and for the rer its a 47-44 and it realy does work much more efficiently. ive tried quite a fiew cams in the standard secondary but nothing worked as well as the stock rer secondary.

Dynamo^Joe
06-17-2003, 01:36 PM
must break 7000 views.....

:devil:

machz69
06-17-2003, 08:54 PM
ill try to help you out joe :sly:

MAYNiacracer28
03-09-2004, 06:22 PM
just read that post now...it only took me about a week to finish it all haha. great stuff DynamoJoe...this winter is winding down in some parts and over in others...lets hear some experiences from this winter.maybe a little bit of engine modding talk?

and Joe you never said how Shooter was doing a little bit of cheating.....

Dynamo^Joe
03-10-2004, 12:05 AM
Our buddy Hamrhead slipped up one day in the garage about RadChad putting a vendor&#39;s clutch kit in that was bought from haydays that previous year. It was put in Shooter&#39;s sled.
My eyes nearly popped out of my head.."WHAT?&#33;!!!"
Hamrhead..."whoops"

...I clobbered that thing. There was women and children crying and everything. Now Shooter has something I put in his 2K zx :devil:

Dynamo^Joe
03-10-2004, 12:13 AM
To keep the tech talk going.....
I just love reading problems people have, however I love more the "Dr. Bunsonhoneydew" answers some tuners offer from their experiences, although it&#39;s few chats of this ilk these days...
...I have a "Dr. Bunsonhoneydew" answer to the constant emails I get about dropping the top gear one or two.


Chewing on theory here...
For simplicity sake lets say;
1] Large angles have great up shift
2] Lower angles have great back shift

Example:
Use a straight 50 cam and you think it up shift too fast because results are "rpm is low"...
Knowing the theory, you go to cam with less degree. A guy may do the same trial run with a 46 cam and the rpm is right on.

With the smaller angle, you slow down the action of the secondary sheave opening in degrees. The lead angle that the button follows is longer. The engine has to create more rpm to maintain at least same speed.

This is the detail that I like people to make a mental note of, sort of like a mantra;
...You slow down the action of the secondary sheave opening in degrees, the engine has to create more rpm to maintain at least same speed.
...You slow down the action of the secondary sheave opening in degrees, the engine has to create more rpm to maintain at least same speed.

Going from a 50 to a 46, the helix resists torque supplied from engine through the belt because of its lower cam angle. Just remember that the roller/button profile, the 46 has a longer path [in inches] than the 50. The sliding sheave opens more in degrees with the 46 and has more of a "Fine thread" effect.
The 46 cam can push back harder against the secondary sheave preventing it from opening.
The secondary sliding sheave resists the primary closing its sheaves together.
The engine rpm will increase because the "push" of the primary is stalled.
***My point to remember here is; The character of a smaller helix angle "stalls" the shift from the primary compared to a larger helix angle.***
A term I like to use a lot is "stalling the shift"

Under acceleration, the 46 helix causes the belt centerline and the center of gravity position of the TRA arm to be lower and closer to the clutch shaft or if you like..the engagement position. The helix resists the push from the primary and leaves the tra arm back in a lower position.

Under acceleration, the 50 helix lets the belt centerline and the center of gravity position of the TRA arm to be higher and farther away from the clutch shaft or if you like..the engagement position. When depressing the fuel to accelerate, you&#39;&#39;ll find the engine will shift at a lower rpm than the 46 helix and the peak rpm could or will be slightly less than proper rpms. You could lose 100 rpm or more because the weight is heavier and pushing harder at the 60mph speed.

We will not talk about the primary clutch for a moment;
Ok so what if we want to increase rpms and maybe quicken the engine flashing thru the clutches?
You know..."I want that instant response of engine to my thumb trigger position!"
You still have to slow the secondary sheave opening. Slowing the up shift = build engine rpm quicker.
NOTE: When I say "Up shift" I directly point at the secondary sliding sheave opening as engine rpm is applied, opening as the sheave rotates in degrees at the same time the belt pushes the sliding sheave away from the secondary sheave. [Moves in a corkscrew motion]

***Alternate way of slowing up shift without changing a helix or spring = GEARING***
We know going to a taller gear slows the up shift more than a lower gear ratio.
Between two points on a measured test track; When you gear up, the secondary spends more time revolving "per" the sliding sheave opening up in degrees.
The belt does not go down the secondary as much in your measured distance trial because the sheaves will not open quickly, thus stalling the primary push.
Pretending to have perfect traction from the start to finish, if you could count the revolutions the secondary makes from start to finish, with a taller gear ratio the secondary would make less revolutions than a lower gear ratio. If you could look at the secondary from the helix side, you would see the secondary would open less in degrees counter clockwise from start to finish.

Experimenting with a 440:
Back in the days I have played with gears of 21, 22, 23, and 24 for the 440mxzx. I found that the taller 23 & 24 gears were ok for flat running where we could get high consistent speeds. Problems arise when the sled got into steep long rolling hills, we would lose a lot of speed. The engine would maintain rpms no problem but the secondary seemed to take too long to up shift and a long time for the sled get back to its top speed.
A simulation would be having an extra person on the sled. Engine is right there, but acceleration is slow.
Good rpms all the time. Good speed if the loads/terrain does not change too much. Very smooth acceleration, but hills slow the mph down.
An extreme example would be TOWING. Has anyone ever had a bog when towing a broke sled? Nope!!! It&#39;&#39;s Impossible to bog!!! Remember what it&#39;&#39;s like? Revving revving revving, very slow acceleration with eventually pulling to trail speeds. Engine is always there, you can lay on the gas and the engine revs great but the secondary turns slow, the shift is stalled.... belt smoke!!! I would have to think a relationship would be like taking your gears and trading them for backwards. Put the big gear on top and small on bottom. What will happen?

When it come to rough extreme bumps at high speed, you have to let off the fuel then get back on it, the 440 engine would flash to peak very nicely but acceleration is slow to get to the fastest speed for the terrain.
Once I started to gear back down to 22 and 21 top gears, the acceleration that was lacking with the 23 & 24 was greatly improved. The same top mph could be achieved very quickly.
The greatest measurements for acceleration in all the trial runs were going back to the 21 gear. With the 21 gear, I could have the same top speed as the 24 top gear if not slightly better. The 21 gear is less sensitive to high loads like the hills and bumps I mention. The sled became hyper again.
To be able to push the secondary open past "the wall" with the 24 gear, the load of the ground has to become lower. The road become smoother, snow dust for improved slider lubrication, track attack angle lower, less drag lower windshield, lighter driver/operator. The load being lower the secondary will open more. If the load is higher then the secondary will not open more, rather hit "the wall" the belt will spin, slipping through the secondary due to lack of belt clamp. The higher the load for example like the snow getting deeper, "the wall" will be hit sooner at a lower mph.

At previous gearing [24] the belt centerline and the center of gravity position of the TRA arm is lower and closer to the clutch shaft or if you like..the engagement position. When depressing the fuel to accelerate, you&#39;&#39;ll find the engine will shift at whatever rpm and peak at the proper rpms.

With the newer lower gear [21] the belt centerline and the center of gravity position of the TRA arm is higher and farther away from the clutch shaft or if you like..the engagement position. When depressing the fuel to accelerate, you&#39;&#39;ll find the engine will shift at a lower rpm than the 25 gear and the peak rpm will be slightly less than proper rpms. You could lose 100 rpm or more because the weight is heavier and pushing harder at the 60mph speed.

In summation, taller gearing will provide clutching that "acts" like the clutches back shift fast to let the engine get back to peak rpm quickly, the up shift at high speeds will be slow. You think the clutch is back shifting quickly because the engine flashes back to peak, however the primary will not be able to push the secondary open. The engine can do nothing but rev then.

Taller gearing "feels and sounds" like having a small angle on the cam for the speed you are traveling at. In higher loads than clean trails, you lose mph quickly and the chassis is slow to come back to peak mph, yet engine maintains peak rpms.

Ever hear that common comment from clutch tuners; I geared up and it seems like my sled is hitting a wall! This comment relates to the exercise below.
Another gearing exercise:
=========================
Against a Pol Pro-X, it geared at 23:43 and my rev 440 geared at 19:44, doing 30mph flying starts, we would accelerate about the same to 55mph where I would start to pull away with me topping out at 80 mph and the Pol hitting a wall at about 72~73 mph.

The Pro-X geared down to 22 top gear with another pass made I would start to pull away about 60 mph right to top end. The Pol about the same 72~73 mph.

The Pro-X geared down to 21 top gear with another pass made I would start to pull away about 62~63 mph right to top end. The Pol increased mph to about 74~75 mph.

The Pro-X geared down to 19 top gear with another pass made I would start to pull away about 65~67 mph right to top end. The Pol increased mph to about 77~78 mph.

From lowering the gear in the Pol, it seemed "the wall" that Roddy was hitting kept going higher in mph. Monitoring secondary temperature we noticed that making a few runs with each change, each gear lower the sheave temperature was lower than previous change.
Knowing that temperature is affected by belt slip, we looked at his helix angle thinking that we could apply more belt clamp to try to capture more top mph through improved belt/sheave friction.

Roddy removed the 48/38 helix and installed a 48/34.

Racing again doing 30mph flying starts, we would accelerate about the same to 75mph where I would start to pull away with me topping out at 80 mph and him hitting topping out at 77~78 mph.
The secondary temperature was very cool to the touch.

Roddy did notice that regardless of being on hard pack or in 6" of snow, with any gear he had in the sled, the engine would flash to peak rpms quickly when he got back on the gas. One thing that was super noticeable was the lower mph in the deep snow with the 23 gear compared to the 19.
With the 23 gear installed, I could literally run beside him slightly burping my gas trigger. His sled was revving at proper rpms, yet his acceleration was slow. When he geared down, it was all my sled could do to stay in front of him.

For fun we went back to remove the 48/34 and re-installed the 48/38. Testing again in the deep snow, the Pol&#39;&#39;s top mph was less with the 38 than the 34.
Promptly Roddy went back to the 34 final.

[b]Heh, in the end here, I get so many questions about lowering the top gear, I figure that two teeth lower than stock is ok by me. Noticable increase in acceleration and maintain top end.
and uhh....my pen just ran out of ink.

f7rocket
03-10-2004, 08:13 AM
OK!!!!the lower the finish angle the more speed or mid range(rite) if i can keep my rpms the same..by adding weight..i got a 60/54 and i want to drop down 300rpm i should add weight instead of a higher degree on the finish angle..is a straight angle helix any good for drag racing..if i put in a stright angle 55 would that help me in 660&#39; how much would it lower the rpm by..the stock was straight 53.

MAYNiacracer28
03-10-2004, 09:08 PM
Joe the 23 43 isnt stock gearing in the pro X is it? Seems pretty tall considering stock in my 600HO is 24 43.

im assuming the "wall" was the clutches not shifting out?

Did you try and gear any lower than the 19 23?

Great info by the way.

Gasoline Man
03-11-2004, 11:36 AM
F7rocket - I think your getting the general idea. As I posted before my bro&#39;s F5 has a 60/44 and it hauls a$$ then some! I know some 900&#39;s and even the older ZR triples are running as low as 60/40 with the same arm pulling results. As you can tell from my PM&#39;s to you I&#39;m not that experienced with drags. Frankly I think it&#39;s kinda boring. But, as for the straight vs. compound helixes: I think it&#39;s easier to tune a motor with the right compound angles then one straight angle. More "manipulation" or the power available.

What&#39;s the harm in trying that 60/40 on your big 700? Won&#39;t know until you try? You may have to use a softer spring or more weight to get your RPM down to peak torque.

Great posts Joe!!!

kragar
03-11-2004, 04:39 PM
Joe, was it just the backshift characteristics on the MAG arms you didn&#39;t like? I run them on my drag sled Tripple and love them. COOL clutches full shift and very quick to REV.

Dynamo^Joe
03-11-2004, 08:08 PM
OK!!!!the lower the finish angle the more speed or mid range(rite) if i
can keep my rpms the same..by adding weight..

JOE]...Yaa! Compensate for increase in rpms with more flyweight.

i got a 60/54 and i want to drop down 300rpm i should add weight
instead of a higher degree on the finish angle..

JOE]...Two ways to push down the rpms, adding flyweight and/or larger
angle finish on helix, however increasing the finish angle will diminish
the sideforce on the belt. Not saying this is a bad thing for drags,
just giving a heads up on what changes will effect the system.


is a straight angle helix any good for drag racing..if i put in a
stright angle 55 would that help me in 660&#39; how much would it lower the
rpm by..the stock was straight 53.

JOE]...I used to gear a 500OM sled for 144mph. I put flyweight in that
seemed to shift straight, however overrev. I started to change helix&#39;s.
Straight 34, take a run 36, take a run 38 take a run.....yatta yatta,
46, 48. Ooh, too much with the 48, the mph was down from 46. I had a
47 made and it was the best for that sled.
Each helix larger the rpms would come down slightly and acceleration
across the whole track would increase.
The sled won 2nd at haydays one year only to be beat by dean schroeder
by a hoodlength.

JOE]...I do not know the answer for your 55 ~ 53 helix question. You
have to test yourself.

Joe the 23 43 isnt stock gearing in the pro X is it? Seems pretty tall
considering stock in my 600HO is 24 43.

JOE]...The pro-x has the small drivers and Roddy the whole time thought
he would change to these gears because it would improve top end. He
installed those gears.

im assuming the "wall" was the clutches not shifting out?

JOE]...Correct. The belt does not have enough clamp on it to overcome
the load of the sled.

Did you try and gear any lower than the 19 23?

JOE]...On the Pro-X?...no we did not. The 19 was the lowest we could go for the chains rocketman had.

I been running around with 18:44 gears in my sled and top end
was down a few mph, I geared back up to 19 then 20, where I am now back
down to 19:44 for my rev 440. I just love the acceleration and ability
to carry the skis over hills much longer than taller gear.

f7rocket
03-12-2004, 11:40 PM
Grate info i appreciate it..going to start at the first again and read it through..alot of good info here and it takes a while to get it all absorbed,but now i think that I&#39;m starting to get a handle on this clutch thing..going to start adding weight and see what happens..lol..one step at a time..might get it dilled in before all the snow is gone for this year!!!!!!

Dynamo^Joe
03-12-2004, 11:50 PM
Originally posted by kragar@Mar 11 2004, 03:39 PM
Joe, was it just the backshift characteristics on the MAG arms you didn&#39;t like? I run them on my drag sled Tripple and love them. COOL clutches full shift and very quick to REV.
Hey Kragar...here is a page out of the book im writing.* I kind of tuned it for a reply to a post over at...
http://www.dootalk.com/forums/index.php?sh...pic=10544&st=15 (http://www.dootalk.com/forums/index.php?showtopic=10544&st=15)


I have often wondered what will be the downside to a light arm system. I know one thing is tuners think these light arms are more aggressive in the bottom end, however I disagree. I know they are aggressive on the top end, but not the bottom end of the midrange.
I think that when people have two definitions for the term &#39;aggressive&#39; that is why there is confusion.
Concerning light arms, my definition of Aggressive is; the heavier arm will start to engage the belt and proceed to shift the clutch, sliding the sheave at a [lower rpm] than a lighter flyweight arm.
The primary is inclined to have action or &#39;more action&#39; &#39;more push&#39; per rpm with a heavier arm on the bottom of the midrange.

Any arm lighter than the factory &#39;heavy&#39; arm is less aggressive.
On your clutch system you leave everything the same but change the arms to a lighter arm, yet compensate with the weight to make the engine pull at its proper peak rpm. The engine will then become revvy per throttle position in the lower speeds and usually these speeds are at 1/2 or less mph of the potential peak mph the sled can go.

Let’s think of a snow-covered hill to go down. What would it be like where you can only do 50 mph safely going down then ascend back up the next rise of for lack of better numbers &#39;A 50 deg snow covered incline&#39;.
A scenario:
With a light arm, you are driving on a hilly trail that has powder snow and can do about 50 mph safely.
You let off the fuel coming down a hill go through the bottom of it and ascend up the other hill. You just got off the fuel and got back on it, the engine will take longer to flash back to its peak power. The sled won&#39;t &#39;get back on it&#39; right away when you punch the fuel. &#39;Delay reaction&#39; or as some sleds I’ve tested the engine hangs there at a low rpm until the angle comes out of the hill and levels out. The rpms then increase to peak.
The [c of g] is closer to the clutch bolt center, but when you are moving along at high speeds, the arm is shifting [ed] out and will tend to stay out. It resists shifting back because the [c of g] is farther away from the arm pivot.
Your secondary has to be more sensitive than before to sense the lack of torque and back shift.
I really don&#39;t like using the word "sensitive", rather needs more pretension or lower helix angle to &#39;compensate&#39; for the increased force the arm pushes out and the lack of torque in lower rpms on a hot pipe at midrange speeds.

Now...next exercise;
With your stock heavy arm, you do the same thing; you let off the fuel coming down a hill go through the bottom of it and ascend up the other hill. You just got off the fuel and got back on it, the engine will be quicker to flash back to its peak power. The sled &#39;gets back on it&#39; right away when you punch the fuel.
The [c of g] is farther away from the clutch bolt center but closer to the arm pivot.
Because being closer to the arm pivot, the arm will tend to back shift quicker.
The secondary will sense the torque from the engine and back shift quicker. Because the engine is allowed to build rpm back into the meat of the powerband, the torque load coming from the engine is greater than the load from the ground. The engine will be right there with increased or proper rpms at your thumb tip.

When using a lighter arm, the arm&#39;s [c of g] is closer to the center of rotation on the clutch than on a heavy original arm.
The engine has to produce more rpm to move the flyweight to shift the clutch.
You apply the throttle and your engine will react with a little more jazz, as it will rev more to move the sled than previously with the heavy arms.
You will be using less of the low rpm torque to move the sled forward and with a hot pipe there is almost always a trade off of low-end torque for top end RPM.
I&#39;m sure you&#39;ve noticed the 800 has less bottom end &#39;grunt&#39; now in the low mph than it used to have however yes, the primary pushes damn hard in the upper end of midrange.

I learned a lot of this and found how much a difference the [c of g] makes on a set of arms with sets of Yamaha arms, Thundershift flyweights and Hooper quickchange arms. You find the amount of mass you need to get the rpms that you want to run. U leave the mass of the flyweight the same and move the composites around on the arm to watch how your sled reacts to the conditions that you want to use them in.
Move the composites close to the arm pivot and watch your engagement go down slightly...you get a more aggressive shift and go to the point where at high speeds you may find the rpms actually raise.
Move the composites away from the pivot close to the roller and watch how revvy the engine will get and how you can actually make an engine pull down rpms at high speeds.

f7rocket
03-14-2004, 02:38 PM
OK!!! now what do you mean about shift straight???is that holding rpms the same all the way to the top?

Ak Machine Boyz
03-14-2004, 07:43 PM
ALRIGHT~~~&#33;!!!! People are jumping around and just saying a bunch of numbers!!! What we need is someone to EXPLAIN what each term means, is, and the effect it has on the machine!!!

Right now im trying how to get my 2001 550 supersport running with alot better top end. I dont know really ANYTHING about clutching and MUST learn about it. Also my friend has a 1992 mach one 700 that can cat walk for as long as he wants, but as soon as he bring it in powder deeper than 6 inches it stops moving, as tho it doesnt have the torch!!! Personally i have never seen a machine that couldnt ride in powder! So if somone would post all of the diffrent tech terms of clutching up with the deffentions i would be EXTREMLEY grateful! Thx alot, Ak Boyz

hillpounder
03-14-2004, 07:53 PM
^joe, I find that calibration that holds rpm on the steepdeep will over rev on the flatgroomed,by about 200rpms. This happens in every mt sled I&#39;ve been on no matter what the brand or size, or who&#39;s newfangled devices are in it. Can the CVT be torque and load responsive enough to adjust for this?

kragar
03-15-2004, 09:53 AM
Joe thanks for the analogy. I am going to test the theory of slower shift at the start of the mag arms you are talking about. But iright now it sure feels like it shifts out hard from the start and of course revs real quick. Remember this is a drag sled that doesn&#39;t lift until the race is over so backshift isn&#39;t a big concern. Traction is usually consistant too.
Question: To compare apples to apples if we can.......Mag arm setup has total weight of lets say 57 grams. All thing being equal what should stock arms weigh know weight will shifted from the pin to the arm???

Dynamo^Joe
03-15-2004, 11:36 AM
Originally posted by hillpounder@Mar 14 2004, 06:53 PM
^joe, I find that calibration that holds rpm on the steepdeep will over rev on the flatgroomed,by about 200rpms. This happens in every mt sled I&#39;ve been on no matter what the brand or size, or who&#39;s newfangled devices are in it. Can the CVT be torque and load responsive enough to adjust for this?
Hillpounder. This is a buddy of mine out in WY who runs from 6000~10000 feet with his 8 hunnid Skummit.

Went sledding today and my sled ran damn good.* Nothing was even close.* I did have to take the hood off to keep the clutches cool but i was out doing a stock sled just like mine, with a 30 lb lighter rider, by at least 40 yard on a damn steep hill.
Still had the clickers on 2 with the emtpy pins.* For the snow conditions it rocked.
In deep powder need more clicker.
We were riding from 6500-10000 ft. when i got above 8500 i think it would have ran better on clicker 4, but i was out doing everyone and could go anywhere so didn&#39;t screw with it.
Tyson

I have tyson&#39;s email if you want to chat about what you just mention.

hillpounder
03-19-2004, 11:24 PM
Thanks ^Joe, from the quote it looks like he runs into the same thing. The clickers are sure nice in the mt&#39;s., can&#39;t believe the other oems haven&#39;t made something simular. I&#39;d also like to see a secondary that was so sensitive to torque/load that 1 calibration would hold rpms anywhere. We&#39;ve tried some of this new stuff that makes such claims, same results.

MAYNiacracer28
03-25-2004, 11:18 PM
Dynamo Joe or whoever:

with a good setup should the rpms flash to peak torque and then crawl to peak horse or should they go straight to peak horsepower?

Dynamo^Joe
03-26-2004, 12:32 AM
Shifting too fast.... (http://www.snowmobileworld.com/forum/index.php?showtopic=25933&st=0&#entry194435)

kragar
03-26-2004, 09:47 AM
Joe, I have one of your helix&#39;s which I am going to try on asphalt this summer. Its the S4x4 I believe. You sold it to a guy here for his MXZ700. I will be running it on a IMP 700 tripple. I think the initial angle is about where I want to test with.

H.O.RIDER
03-27-2004, 04:16 PM
Hello Joe:

Just want to pick your brain for a moment.
Over the last few seasons I have tested many, many clutching combos on my 670 HO&#39;s. You always refer to "straight shift" as something you want to achieve.
I have found in side by side testing that when this sled pulls from the torque peak or slightly above, to the hp peak, it is a faster sled than if it were set up to pull the hp peak out of the hole and hold those RPM&#39;s. Maybe not the best in all situations as I know you try to tune for, but none the less, a faster sled in drag or most trail conditions.

Is this situation more pronounced on RV motors or do you see benefits in a straight shift on these sleds also.

Maybe I just dont understand your definition of straight shift.

Thanks

Dynamo^Joe
03-30-2004, 07:41 PM
JOE]...I think this is pronounced because of your clutching. With the
condition you have, I would like to see how the sled will perform in
deep snow. Fine while you pull off the trail and get in the snow,
however as the exh pipe gets superheated, the torque loss at lower rpms
will catch up with you. Let the throttle off then get back on it and
the engine will "hang" at lower rpms. Nothing to do with clutches
getting hot either. Pipe temp gets hot you get benefit of peak rpm hp
with a loss of torque at lower rpms. Cold pipe torque is higher at
lower rpms and peak hp is reduced at high rpms. Now with hot pipe when you try to get the engine to recover because of torque loss when
pressing the fuel trigger the clutches do not backshift. Need the
engine torque to backshift. Now the trail happens to get pretty bumpy
which puts demands on the clutches you&#39;ll probably again find low rpms
momentarily when you let off the fuel then get back on it.

I don&#39;t think climbing rpms are pronounced in any engine. It&#39;s
clutching.

Maybe I just dont understand your definition of straight shift.
Can you remember when the sled was new? Take the sled out for a run
you hammer the gas and the engine hits 8000 on the tach and stays there
from when you punch the gas right to top speed. So regardless of speed
when you let off the gas then get back on it the engine will hit 8000
rpm. In the mild snow or hardpack trail you are on the gas the engine
runs at 8000, you let off the gas then get back on it....8000.
That is my laymen term of straight shift.

H.O.RIDER
03-30-2004, 08:06 PM
Well, I couldn&#39;t have asked for a better answer. Thanks.
Would you agree that clutching of this sort is drag race specific?

In regards to your description of straight shift, the sleds I run were never clutched this way out of the box(670HO). Was it poor clutching? Or was it intential for straight line hardpack performance. The factory selected ramp, spring, helix combination meant low out of the hole RPM on every HO I have seen.

Thanks Joe

MAYNiacracer28
04-03-2004, 12:25 PM
I was reading over on snowest to clutch first to load the motor and then jet. Under the theory that when the motor is loaded properly it will need more fuel than when it isnt. this made me think of Dynamo Joes notes on his first day of tuning the 440. Any thoughts?

Dynamo^Joe
04-05-2004, 02:41 PM
Testing for grass drags....
As we went along looking how the 440 hooked up, the better we got it to hook up there ended up being this little bog come out of it.
With different torsion springs and having the rear/rear shock valved with more rebound to slow the return down the bog became more pronounced.
I would have to stand in front of the sled about 200 feet away to listen to when the driver would press the gas. Standing this far away you can hear different sounds of bogging. "Bubbling" is rich and a hollow sounding "bahhh" is lean.
I would hear a "bahh" sound and say "whoa is that ever lean". Step up the pilot size and a few tests the sound diminished. To hell with it....throw big pilot in. "Blammo" Manomanoman the holeshot was incredible now.

We cleaned up the bottom end so good with suspension tuning the skis would not bounce off the ground, rather simply come up so high and float there as the sled accelerates making for good clutching. When you have a bouncing chassis the clutches get confused as the sled comes up and slightly unloads, then the chassis lowers...this happens a few times per second [capture on video camera] The torque goes up and down and what does the secondary want to do?
What does the secondary want to do as soon as the track spins?

Anyhoo...heavy steady load off the start line made us put a larger pilot jet in the engine to make it pull harder.

MAYNiacracer28
04-06-2004, 09:11 PM
So i see how jetting relates to hooking up....but have you ever went from good jetting with stock clutching then after you have gotten it dialed in a bit have the jetting lean out? For example when you did the clutches on the 440 on the notes you wrote to us did you see any changes then?

Dynamo^Joe
04-12-2004, 09:01 PM
You mentioning notes....if you are talking about clutching weekend back then 4 years ago I did not know about the jetting helping out with lean bog due to improved hookup.

I can only say I would never have told the difference as we tested on a snow covered lake where basically to get best traction I had to plop my fat arse on the back of the seat with all the suspension gizmos turned to "transfer".

Only started to learn this from testing on ice/grass and great explanations from Freddie "SUPERTUNER" Klies. Then really found good info with proof when I put the lil&#39; 440 on the inertia dyno.

MAYNiacracer28
04-16-2004, 11:40 PM
yup those were the notes. what exactly is the proof from the inertia dyno...inertia dyno same thing as a chassis dyno?

and what is a reverse cut helix good for ie 37/44 etc..... seems like they go against theory of big angles to start for quick upshift then go smaller finish for backshift and top speed........

Dynamo^Joe
04-18-2004, 12:05 AM
The inertia dyno I went on is basically a 1200 lb drum that is hooked directly to the engine via a gear reduction.
You can have a read over here...accurate information. Look for a paragraph called "The Dyno"
http://www.mxzx-revzone.com/dyno.htm

I think reverse cut helix work pretty good in drag racing and you most likely will see them on sleds with unusually high amount of track picks/chisels. For fun lets say on a 440 Cat sno-pro with 192 picks, you might be using a 42/48 reverse helix. An 800 something-or-other with a 44/48 reverse helix. The start angle that is lower with combination of heavily picked track with the proper "high" engagement you can literally incinerate the track and holeshot like the sled&#39;s possessed. Some guys go for crazy track spin and clutch for it.

The other school which is common is to reduce spinning to increase holeshot by using helixes like 56/42 "for lack of better numbers".

MAYNiacracer28
04-18-2004, 10:26 PM
ok makes some kind of sense. seems like it would work good on a bigger trail stock sled since you cant lower it or run pics. im assuming your mention of higher engagement would be to help it upshift faster since you have a lower start angle? and the same with the finish angle to help it shift out quicker???

"Some guys go for crazy track spin and clutch for it." want to elaborate on that?

and using the 56 42....use the 56 to load the motor heavy at the start to actually lug or bog it down so it doesnt "flash" to peak rpms. is that the theory with that?

Gasoline Man
04-26-2004, 12:28 PM
I can&#39;t provide any constructive comments as I only learned a few months back why some of the "old school racers" use the reverse cams for drags. But, my buddy put a reverse cam on his 800 REV open mod this weekend. I think It was GP-37/50, but talk about AMAZING hole shot! I&#39;ve never felt that amount of G&#39;s on a sled before! But, to try and answer your question - the cam holds the belt better on hole shot then as as the sled shifts out in the secondary and the angles increase, the cam starts to release the belt near top end. At least that&#39;s how I understand it. When your drag racing you want lots of pin weight any way. That weight should keep your engagement down to where you want it regardless of the shallow start angle. I wouldn&#39;t use this setup for any other application other then drag racing...

My 2 cents.

BubbaDoo
04-26-2004, 07:30 PM
I have been reading your information on clutching for about a year. I do grass drag and did pretty good but wow look at all this info for dialing in better. It is amazing stuff and I have learned alot. I plan to be dialing in several sleds, both modified and stock, for grass drag racing. I was wondering if there is a way to get a troubleshooting flow chart for any problems I may encounter. For example, if the primary clutch gets too hot, what should I do to correct this, it all here in this site but would take a great deal of time to put it together?
I do believe that some of the best tuners are on this site. I am hoping that I can get a flow chart put together from some of the best people on this site. I think that all the information I need is available here, but I am looking for an compiled way to access what we all need. I have printed out about a book&#39;s worth of information.
On most of these sleds, I will be starting from scratch. What is the most important thing to do first? Should I concentrate on gearing and dialing in the primary? I would hope that you all would have fun giving out info from a start to finish on how to dial in a grass dragger, with all the problems that anyone would encounter on the way. My test mule was a 97 Mach 1 177hp @8800 with grass track 38 bored out, reeds, domes etc. I am buying Tsa and starting to dial in a month from now, after freshning up the motor new pistons, seals, squaring up the motor and frame.

I am hoping this will strike a lot of interest.

Thank you
Bubba

Dynamo^Joe
04-26-2004, 10:11 PM
* I’m assuming your mention of higher engagement would be to help it upshift faster since you have a lower start angle? And the same with the finish angle to help it shift out quicker?
*"Some guys go for crazy track spin and clutch for it." want to elaborate on that?
I mention higher engagement to purely get closer to where the torque starts to rise on a dynograph. Example: My little 440 has no ballz until 5800~ "thereabouts" and the torque starts to climb from 5800.
When I leave at 5200 rpms, the hp there is only about 40 hp. At 5800 there is 50 hp and the torque curve starts to climb nice and fast at that point.
I "brake-rev" my engine to 5600 at the last second before the light/flag goes and have decreased my E.T.&#39;s by a 10th to 2-10ths. I have a little timing system and this is repeatable repeatable repeatable. The sled comes out of the hole smoother with less bounce...etc and quicker ET. The smaller the engine you really have to work to get the sled off the line.

Now me mentioning trying to get higher engagement; Where would you want to engage?
40 hp? Or 50 hp?

These guys who hold their engines w.o.t for 5~6 seconds without letting off the gas at the start line are building pipe heat for a gain in peak hp, however they are losing torque at lower rpms. The hotter they get the pipe, the more peak hp at peak rpms...however suffers torque loss at lower rpms. What rpms would you want the engagement at? Regardless of pipe temperature, you want the engagment near or where the engine starts to produce torque.
***The secondary is torque sensing. The sheave opens when torque is applied and retracts when torque diminishes.

and using the 56 42....use the 56 to load the motor heavy at the start to actually lug or bog it down so it doesn’t "flash" to peak rpms. Is that the theory with that?

***The secondary is torque sensing. The sheave opens when torque is applied and retracts when torque diminishes.

I mention hot pipe, now I mention cold pipe. With a cooler pipe you get increased torque at low rpms than with a hot pipe, however for a loss of peak hp at peak rpms. More torque at lower rpms with this pipe condition you take advantage of extra foot lbs. in the bottom end with larger helix angle and as "pipe heats up/hp increases/torque diminishes" then you want to take advantage of hp and higher rpms with lower helix angle.

My mantra that I live by is for the tuner to learn to use "The helix angle required for the speed they are going at"

Gasolineman writes:
But, my buddy put a reverse cam on his 800 REV open mod this weekend. I think It was GP-37/50, but talk about AMAZING hole shot! I&#39;ve never felt that amount of G&#39;s on a sled before!

I have a setup that does not use reverse angle where upon your return removing your helmet you&#39;d say the same thing. :D

BubbaDoo writes: For example, if the primary clutch gets too hot, what should I do to correct this,

I always like to take temperatures of both clutches on the sheave surfaces, especially the sheave surface of the secondary and not on the outside of the sheave. I like to test where the belt actually touches. To keep this short I have found that when clutched good for the trail regardless of sled I&#39;ve played with, the primary sliding sheave and both sheaves of the secondary are cool. For some reason I have no idea I always find the fixed sheave on the engine warmer or hotter than the other 3-sheave surfaces.
If I find the secondary sheaves cooler than the primary I always suspect over revving or if it does not seem like overrev then I still will add slight flyweight to make the primary push harder. If you are not pushing hard enough in the primary then the belt will slip through the primary sheaves more than the flyweight should allow. More flyweight will push harder and have less belt slip at any imaginary point going across the sheaves as upshifting is being altered.
In the end, I have lowered temperatures by adding slight more flyweight.

What is the most important thing to do first? Should I concentrate on gearing and dialing in the primary?

I always go for a troubleshooting approach. I like to hone my skills making more effective solution at solving or anticipating problems in clutching. If you pay attention to small elements that collectively make for a good system then you will eliminate problems you won&#39;t ever second-guess yourself.

When someone brings a sled to me regardless of mods or stock I always check these elements and make sure their values are right.
1]Secondary Belt Height. I like to have the chord slightly showing in the secondary. [Personal pref]
2]Good Belt Deflection = Track Movement. Fluid movement, jerking slowly or can move with fingers.
3]Primary Belt to sheave clearance
If you have the first 3 down good then you will never have to worry about a bog coming from any of those details...

4]Primary Clutch Weight
5]Find where exh pipe starts to work.
6]Adjust engagement
7]Secondary Pretension
8]Cam Selection
9]Gearing Selection

Belt Selection = combination of 1,2,3.

Gasoline Man
04-28-2004, 10:11 AM
I have a setup that does not use reverse angle where upon your return removing your helmet you&#39;d say the same thing. :D

Oh good, cause I was going to hit you up for a good drag race set up / kit ;O)

This doo factory open mod is awsome! 170+ hp and she easily hits 94 to 100 mph way before 500&#39; mark on the 660&#39; strip. Nothing could touch it out of the hole. We put in a reverse cam for $hits and giggle and low and behold it worked great. As you can tell I don&#39;t know much about drag racing cauze I never really got into it. Frankly it always kind of bored me. But, my interest has been resparted. My bud gave me an old Polaris 650 triple that i want to refurbish and transform into a drag sled. But back to the reverse cam - I can understand the principle of it and they are probably most effective on high hp, high torque motors but, I would presume they would be delinquite of considering the available torque produce and the amount of load required to haul it down the strip? With the litte bit of drag racing I have done (nothing to brag about) I&#39;ve always use and had a bit of success with steep dual helix angles. I&#39;m just starting to inderstand "conformative thinking" doen&#39;t always work in drags....

2 cents.

BubbaDoo
05-07-2004, 10:31 PM
I want to thank everybody for info. Here is something to think about what about stepping or notching the helix at the top of the angle, has this been done?

Bubba

Dynamo^Joe
05-08-2004, 10:55 PM
I tried a few times. At first I sent a drawing to Dale at Dalton and asked him to make me a helix with a start angle of 30 degrees for about .050" and transition to a 50 angle and he said "umm, no!"
Ok, I had a whack of straight 44 helix&#39;s and took a bunch to work. On a milling machine w/a dividing head I had a machinist whittle a 25, 30, 35 deg angles then I put them on a belt sander to make the transition to the 44 deg.
The 25 I broke a fairly new set of rollers. I would pin the gas and the engine would go to 9000 rpms and the sled did not shift. Went about 5 mph. he he $100 set of rollers down the drain.
I got my father to make me a set out of slider plastic and flattened them too. Same results when pinning the gas. All rpms, no forward movement to speak of and crushed rollers.
Got my father to make me some aluminum rollers and with the helix&#39;s the same results, engine rpms right off the tach, slight forward movement.
I gave up.

MAYNiacracer28
05-14-2004, 11:14 AM
DJ what about a less drastic bit of a change, i was thinking of seeing if i could get one cut with a 47 step for a tiny bit for traction then into a progressive 54/40(just an example) something er other.

Dynamo^Joe
05-16-2004, 07:45 PM
Heh, so the shape of the profile would slightly look like an "s" curve?

What character do you think the engine will take on with the 47 then transition into a 54 in your example?

I&#39;d like to know what you mean of "tiny bit of traction" What are you trying to avoid?...What are you trying to improve.

MAYNiacracer28
05-23-2004, 11:11 PM
whoops i meant to say "...for a tiny bit(of the helix ramp), to get traction". like now my sled has 48 44. i do not hook up well im going from 120 to 168 studs. but im thinking if i went with a normal 53 40(the finish angle 40 just for example) i would just blow out bad. but with a small portion of the helix at 47 degrees that would theoretically allow me to gain traction off the line then it would step into normal progressive 53 40......

I have no idea what character my engine would take going from the 47 to 53. i guess thats what they made the word testing for. probably will be a bad money and just cost me $$$

machz1
05-28-2004, 03:50 PM
Originally posted by Mikadoo@Apr 8 2003, 06:05 PM
I too would like to hear some opinions on clutching.
I need help in understanding what different spring poundages in the primary do, also all the different ramp profiles.
Here is a setup I want to try next winter on my 809Z
280 ramps
200-380 spring
19gm pins
50/44 helix
21-23# tention
24/44 gears
230# rider
1 1/4 long track
stock pipes, stock engine
I just want a good all-around go fast set up, not all out racing only.
Any opinions??
280 ramps are very quick to shift out, your stock pins should be 16.9 grams and your spring should be 230 380 giving you an engagement of around 4000-4500 approx, if you go to a 200 380 with 19 gram pins she&#39;ll fall on her face at engagement because 1; the lower engagement of the 200# spring 2; the added weight of the 19 gram pins 3; the 280 ramps very aggres, aka its a lower rpm ramp designed to shift quick for draggin,speed runs etc etc.also if you decide to increase pin weight keep in mind you&#39;ll need to run between 24-26 pounds pretension on the secondary to prevent belt slippage, approx b-5 position with a beige spring. your helix sounds perfect for a proggresive, if you decide to try a straight i would reccommend starting at 50 and working down till you find one that feels good to you. for general trail riding with that sled i would go 286 ramps 230-380 or 250-380 pri spring, try the 19 gram pins and watch your top rpm you want to be at about 8400 if your rpm gets pulled down to low on top switch your spring in pri to a 230-410 or 250-410.you can adjust your clickers from there.try and keep your clickers in the lower numbers cause your sled will pull harder due to the ramps standing straighter up and down relative to the crankshaft exerting more pressure on the belt.one more thing, pri springs, lower poundage on bottom number= lower engagement,lower poundage on top number= lower rpm on top,and vice versa.helix&#39;s, higher angles=faster upshift (50),lower angles=faster backshift(44)