[fullthrottlezrt]

I have a 99 zrt 600 I was thinking of doing some gear changes to it, its has some clutching done to it now nothing radical and its studded id like more low end and mid range for trail riding any suggestions? right now it engages around 5000.also when you change the gears does it make it run in higher rpms all the time? im new at this would appriciate some info  thanks

 

[sled-head]

What gears do you have now??

 

[phazerhater]

Try 22/37.  Those are the gears I am currently running and they are great for aggresive trail riding and if you run radar runs(1000ft)it is great for that as well.  You don't sacrafice much on top end either.

 

[phazerhater]

Also, if you are running all stock you shouldn't rev over 8500rpm.  You will just be over reving and end up losing power.  Try to keep it between 8200rpm and 8500rpm.
And if you go with the 22/37 gears, run a black and purple primary, stock secondary, and 54A gram weights.  Engagement will be around 5000-5200rpm and you want to fully shift at about 8400rpm.
You will be impressed!!

 

[fullthrottlezrt]

thanks for the info guys, this will be my summer project for this sled.  

 

[sleddinfool]

I currently have the 22-37's in my 99 as PH recommends. Iy is a wicked package. D&D had me run 21-39?"s. I beat my brothers ZL800 up to about 50mph with these and he passed me, once he got about 20' on me thats all he could get. We were so close I tried to "draft" him and get by, all that happened was the ice etc.. he was thowing out blew my headlight into the hood. I switched back to the 22-37's and we haven't had a chance to run. That set has incredible top end. I of course have D&D pipes and power breather and a mono-block head sleeper kit, v-force reeds etc... I run mine at 9330 rpm's. Kevin

 

[phazerhater]

I ran the previously mentioned setup in stock form and now have Boyeseen Power Reeds, advanced timing, PSI modblaster stage 2 pipes and silencer, PSI modblaster clutching combo, and the same gears.  Haven't had a chance to run it with the new add ons, at least a full run(broke the chain first time out with new mods, too much hp.hehe)JK.

 

[phazerhater]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (ZRT600MtnCat @ Mar. 26, 2002, 11:29pm)</td></tr><tr><td id="QUOTE">And the 22/37 is a .594 ratio, 19/39 is a .487 ratio if you do the math, the 22/37 is a taller gear that allows more top speed, if you are looking for a quicker gear a 20/39 or 19/39 IS the way to go.[/b][/quote]
It all depends on how much top end you are willing to sacrafice.  I wanted to get as close to the best of both worlds as possible(quick AND fast) and those gears are what worked best for me for what I wanted them for.
If your sled makes more hp and pulls better at higher rpm, so be it.  Most don't, it just "sounds" like it is.

 

[ZRT600MtnCat]

fullthrottlezrt,

Here, let me break it down for you:

I have a 1998 ZRT600.

I took out the 23/40 gear which has a .575 ratio and installed a 20/39 which has a .513 ratio.

According to Black Majic, the 23/40 has a top speed of 98.4 Mph at 9,000 RPM

And the 20/39 has a top speed of 88.6 at 9,000 RPM.

When I switched gearing, I left the clutching factory stock for my ZRT,

The engine RPM topped out with the 23/40 at 8,500 RPM, with

The 20/39 my RPM now tops out at 8,900,

Black Majic says the ZRT600 can safely run at 9,300 RPM.

I know that spedometers are off a little bit

But my speedometer was at the 100 MPH mark wide open at 8,900 RPM,

And it got there ALOT quicker.

I have an 8 tooth driver instead of the factory 9 tooth to add clearance for my 1.5 136 paddle track,

I installed a speedometer gear drive that matches the 8 tooth drivers.

Changing just the gears does not need speedometer gear drive change though.

20/39 with 8 tooth drivers is like running a 19/39 gear.

The clutch engagement is not affected by gear change.

My ZRT pulls alot stronger at 8900 RPM, there is a noticable gain in power at that RPM,

And the 22/37 is a .594 ratio, 19/39 is a .487 ratio if you do the math,

The 22/37 is a taller gear that allows more top speed,

If you are looking for a quicker gear a 20/39 or 19/39 is the way to go.

The rotating assembly on a stock ZRT is capable of sustaining 9600 RPM without breakage

But the power loss usually starts around 9,300 rpm due to port configurations,

This is why the aftermarket companies recommend 9,300.

You ever build a drag race car, or a capable tow rig?

The fact is that the 22/37 is like putting a 2.76 in the rear end of your truck

And the 19/39 is like putting a 3.73 gear in your truck.

I tried it and it works, I am still able to pull my sled over 100 MPH and get there ALOT QUICKER,

22/37 is not a good choice unless you build your sled to run slow RPM, a torque motor,

But the ZRT600 is in fact a High RPM engine, that is the way Arctic Cat designed it.

More RPM means more power, 9,300 RPM is what D&D and Black Majic recommend,

This is how they make their money, they are the ones I will take the recommendations from.

My information comes from these Professional Engineers.

Besides, with a 50 Mph speed limit on the trails

And 100 MPH is actually too fast for most conditions.

It is the quickness of the lower gear ratio (20/39) that helps you in the deep powder and when doing jumps.

 

[Darryn Duncan]

This may sound like a stupid question, but do you have to replace the chain when you change your gearing?

 

[phazerhater]

Zert, depending on which gears you go with you will have to change chain.  Mainly less teeth=less links/smaller chain...



Last edited by phazerhater at Mar. 27, 2002, 4:02pm

 

[sled-head]

I know that a 23/40 you can run stock chain.....I think its a 76 link and to run the 20/39  you have to drop 2 links to 74. I run the 23/40 in my 900  and its scary fast but falls off after 90mph but still does well over 108 mph...I tried 20/39 in my 800 and I almost got whip lash it pulled so hard.......but with the low rpm's I could only go 90mph so I went back to 24/39 with my Black Magic Kit.....With the kit I could only get 97mph on gps and I think BM lied to me because they claimed more top end than that on the phone......The D&D kit  is still in the box because it doesnt work.....

 

[ZRT600MtnCat]

Did you get that information I sent you fullthrottlezrt?

 

[6]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (ZRT600MtnCat @ April 04, 2002, 9:22pm)</td></tr><tr><td id="QUOTE">Did you get that information I sent you fullthrottlezrt?

[/b][/quote]
I got it. And I didn't think it was funny whatsoever. As a matter of fact, I wouldn't recommend doing it again...

[webmaster hastily returns to the Admin Control Panel to turn back on flood control for users like this]

 

[Cat Rider]

I don't get it, why are you picking on ZRT600MtnCat? his post was very informative and I appreciated the thoroughness and detail. Very Impressed with his knowledge on this subject, Right On The Money, Worked great, thanks alot ZRT.

 

[6]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Cat Rider @ April 13, 2002, 5:33pm)</td></tr><tr><td id="QUOTE">I don't get it, why are you picking on ZRT600MtnCat? his post was very informative and I appreciated the thoroughness and detail. Very Impressed with his knowledge on this subject, Right On The Money, Worked great, thanks alot ZRT.[/b][/quote]
Because he posted the same message about 12 times, that's why... (once would have been sufficient)

 

[newf]

Topic closed!