Would like to hear your comments about this statement:




"Last year, we spent over $2000 on every conceivable aftermarket super-whiz-bang clutching component on the market trying to make the sleds faster. The bottom line was and is that if you have two sleds that turn the right RPM, no matter how you get there in the clutching, they run the same. Magnesium arms, titanium springs, roller driven clutches - none of it made the sled any faster. Some of them did make the sled feel different, but never made enough difference that we could recommend that you spend money on them. We even ran with sleds that had custom ground ramps and different springs - again if the two sleds turned the same RPM, they ran the same. "


http://www.xtreme-performance.com/snowarti...les02summit.htm (http://www.xtreme-performance.com/snowarticles02summit.htm)


edit to add link

on the surface I'd have to agree.....maybe with one exception, acceleration might be a big difference between setups.....top end would have to be the same if clutches are equally shifted out running same rpms'.........you'll have to define "faster", as in acceleration/top end/both.....and it will vary between people, to me 6 sled lengths in a thousand feet isn't really that much faster, where some people think it's day and night....when I ride a vmax4 after being on a 300 Enticer, that's faster....

to make the sled "faster", in my opinion your can only play with the gearing, if this statement refers to top speed. if "x" sled has it's highest out put at "x" r.p.m. then sure, that's all the faster it will go, with that gearing. but in my clutching opinion, if i can get to 100 m.p.h. in 600 feet and it takes someone else 1000 feet to get to 100 m.p.h., well i guess i'm faster then. the "no matter how you get there" part is the one that matters to me, as well as how fast you get the r.p.m.'s to your sleds top performance level, and what the speedo does when it get's there.

faster is NOT always quicker . i do 108 mph in 660 ft at 6.10 seconds , and i see others take 6.50 sec to get to 108 in 660 so i win in my book. but his point is well taken and i believe that if you push the stock stuff it will out do most other items you will spend needless coin on

I learned a long time ago that when it comes to clutching there are many many ways to acheive the same results... Ive seen some methods in the past that were a bit unorthodox IMO but hey if it works for ya who cares.

For me personally I find that statement nearly incapable of being interpreted any other way than they were very restricted in what they did.
Did they do any trouble-shooting?

They offer no clues to what they did for exersizes.

Giving the restrictions they use to perform, I bet that if they could measure two sleds with the same rpm and one of these sleds had a cooler secondary, the one with the warmer secondary would be slower in acceleration and top end due to hp-to-ground being lost in heat.

Heh, They must have been doing this as a full-time job.
I would tend to think that there is no whiz-bang component that is trouble free.

dumb question...please explain how the secondary gets hot (other than belt misalignment, binding, etc.)..I have zero experience playing with clutching so bear with me..or for that matter when people talk about clutches being hot, what is the obvious reason for clutches getting abnormaly hot???

I would say just for one example is from lack of force the secondary sheaves clamp the belt.
The belt passes around slipping thru the secondary causing heat.

To try to lower the temperature would be to put more clamp force against the belt. I have found several times to use a spring with a compressed force higher at full shift to lower heat than an original spring.

I'll just ramble here.......
...one of my fave budget changes is say on a Polaris 500 thru 700 sled that has bone stock clutching. I like to only change the secondary spring.

The oem spring is a Sil/blu spring
The spring i like to replace with is either a Ski-Doo-Beige or a ACat-Yellow.

The beige and yellow spring have "if I remember right " about 25 lbs more force at full shift than the sil/blu. The Bg or Yl spring pushes the sheave against the belt with approx 25 lbs more force at top end.

So now the owner goes and runs the sled, they find the rpms are right on or nearly right on and top speed is improved. Do a secondary temperature test with the oem spring after a few runs, then do a temp test with the new spring and they always find the secondary sheave is cooler to touch with the new spring.
...same rpms.

So I would tend to think that the "HP lost thru heat" is now "HP captured" because the belt has got more clamp. I think it just so happens to be lucky with that other selection of springs [Bg & Yl] that they have just enough force required to produce better clutching without having to change the flyweights because of possible overrev.

might find some interesting reading over here...
http://www.snowest.com/fusetalk/messagevie...&threadid=82125 (http://www.snowest.com/fusetalk/messageview.cfm?catid=3&threadid=82125)
Forums:Performance Modified.
About 1/2 way down the page it gets kinda deep into "clamp talk" or "B.S." hahaha....

hmmm, I just assumed no belt slip was a given (in any normal clutch setup)...shows how much I know...if you go to the other end of the spectrum, what are the obvious detriments of too much clamping force on the belt, lack of full shift?

What sled do you own?...
...i'll come back to this post and modify it after...


K writes:
if you go to the other end of the spectrum, what are the obvious detriments of too much clamping force on the belt, lack of full shift?

J writes:
...lack of "any" shift. As an example just by spring compressed force alone if the spring has enough force to ovecome the push from the primary, then the secondary sheaves will not let the belt shift down the sheave surface towards a higher shift ratio.
...if the primary cannot push, then the engine will tend to overrev.

I used to go spend whole afternoons on a lake with my mxz testing secondary springs. Prior to a day of testing, I would go thru all the springs I had and set them up in a secondary with 18 lbs, then write the setting down for each spring to go do runs the next day.
For a certain exersize I would install secondary springs all at the same pretension and then go test how fast I could go down a lake. Wanna see a 440 mxz turn 10000 rpms? LOL....Stick a Yamaha Black/Pink stripe secondary spring in at 17 lbs and see what happens....or a ACat Green spring, Red spring....etc.
Anyway the temperature I could rarely get over 80 deg F.

Another exersize I would measure how many lbs torsion "pretension" the Beige spring had at full shift when the sheave is open ccw fully in degrees.
I would take all those secondary springs and try to get the force in tension to be the same at full shift as the beige. So say for that AC Green spring to have 30+ lbs like the beige has, I had to set the Grn up with about 8 lbs pretension.
...still would get massive over rev due to compressed force at full shift...
...even though it would never go over 50 mph because of overrev.

I m/c my secondary and helix's out, then grind the buttons to accept these larger dia springs to fit inside.