[zrt900]

Hi All

I am so close to getting my clutching to where I want it.

I need a little input though.
I am running 10-62 Pol weights,yellow white AC spring. Red white Secondary spring and a 60-48 helix.

I was running the AC orange white spring but my engagement was to high for my liking.

I like the way all works now but I lost my top rpm with this spring..
orange -whit is 143,290
Yellow white is 122,185.

I know I can wind the back clutch some more to bring rpm up but would prefer to do it with a primary spring.
I likely need around a 120,295 or so.
With the orange spring in it would turn 82-8300 rpm on top. Now it is 81-8200.
This was on a snow covered lake . Once on hardpack I think it will be lower again on the top rpm.


Am I on the right track?
More pressure on top of the spring to bring the rpm's up?

Any one know a spring with these numbers.
I checked and foound an EPI with 125,300 but I wonder if the 300 would be too muchon top.
Aaen shows a listing for 120,290.

I have a set of 10-60 Polaris weights available to me.
With the Pol profile would this lighter weight possibly raise the rpm on top?

What would it do to the engagement lower,higher or the same.

Come on guys I know there are Many more knowledgeable clutch tuners out there than I am.

This is on a 1999 ZRT w Ported 900 jugs,3 deg timing key, shaved heads..Rest basically stock

Thanks for any help .
badcomputer

 

[zrt900]

ttt

 

[99thundercat]

i use the same secondary setup but i use a red arctic cat primary spring and 60g polaris weights

 

[zrt900]

What is your engagement with the red and 60 gr weights?
Top rpm at w/o throttle?

I am close in hp to a 1000 with the key and porting.

thanks

 

[sellery]

zrt900...I have a 2000 T cat pulling about 180 hp. I started messing with air box, jetting etc and gained about 8 hp from stock. Once I did that I adjusted my stock clutching. I run a yellow white primary spring and 55 gram weights, red/? secondary and a stronger helix silimar to your set up. I am actually reving at about 8800 at top end. TOO much! I am adding 57 gram weights to put the hp to the track and should drop the rpms to about 8500.

What I like to do is put the spring in that I want and then match the weights to get rpm that is in best hp band. If you trail ride you will want a yellow/white or even a yellow/green primary spring. This will keep you from jerking at low speeds with engagement. If you like dragging or ditch banging than go with a strong primary and high engagement.

 

[zrt900]

sellery

What are you engaging at with the 55's?


I like the shift of my present setup but need more rpm on top.
It likes to turn 8500-8600 with the porting .

Now turning 7900-8000 , too low.

Thanks EXT

 

[wbrooks]

Does it run 8100 to 8200 all the way through the shift or just drop off a bit at the top end? If it is all the way through then changing the weights to 60g will add about 135 RPM extra. If it is just at the top end maybe a lower angle finish on the helix. AAEN has a 120 - 290 spring that may do exactly what you want

 

[zrt900]

Wayne

It hauls the 8000-8100 all through the shift.
I tried it at 30 mph -40 mph 60mph 80 mph and so on.
If you wack it hard it backshifts and GOES.

All I need is more on the top.

I guess I will be ordering a spring.
EPI has a 125-300 and Aaen has the 120-290.

Thanks
EXT

 

[zrt900]

ttt

 

[KevinS]

How much does the helix change the RPM? I have a 60/40 and I am running 8500 RPM and I want to change it out for a 60/50.

FYI here is my setup on my ZRT 1000.

Polaris 10-58 weights
Goodwin Purple drive spring 140-360
D&D 60/40 helix
Goodwin Silver driven spring 70-125 in 3rd hole

This setup gets me to 8500 but I'm also not sure I like the engagement. It is close to 5000 RPM. I would prefer to get down to about 4500.

I tried 10-60 Polaris weights and in order to get to 8500 I need to have the secondary spring in the 4th hole.

A lot of guys recommend the D&D teal drive spring which is 170/280 but I can only get to 78-7900 RPM with that spring. I think my weight is really messing me up because all suited up I am over 300.

 

[wbrooks]

ZRT900, pop the 60's in and see what you think before buying another spring.

Kevin, the higher the finish angle on the helix the more likely the top end full shift RPM are to fall off.
I think of it this way. At 90° helix there is no slope so as the clutch shifts out there is no extra loading of the spring, the clutch would shift out too fast causing an under rev condition. If you imagine now 20° helix the slope would be very shallow and the ramp very long. As the clutch shifts out now there is a tremendous amount of extra twist added to the spring, similar to several holes of preload this would cause a large force for the primary to overcome and cause an over rev condition.

I am no master tuner but that setup seems a bit strange unless you are in a lot of powder were you plan on seeing a bunch of track spin due to low traction, the large helix split will help that but for normal trail even a 10° split is large. All things equal that teal spring may have only got you 7800 RPM on top but the engagement should have increased as well. You may want to talk to Goodwin or D&D and see what they recommend since you have a some of their parts already

 

[sellery]

sellery

What are you engaging at with the 55's?

With the yellow/white primary spring and 55 gram weights...and 62/54 helix, red white secondary spring I am engageing at 4300 rpm but maxing near 8800 rpm. Too high for modern day rubber design (belts). I am going to keep the same set up but try 57 and maybe 60 gram weights and see what happens

 

[zrt900]

I put the 10-60's in tonight. We are off to Northern New Brunswick tomorrow night for a 5 day trip.
I am taking the 62's along in case i'm not happy with the 60's though.

 

[twentybucks]

I have a 99 zrt800 with ported and polished 900 cylinders and heads, Vforce reeds, DnD 1000 trail pipes, power breather, mbrp can, I removed one shim out of the primary used a factory cat yellow/green spring with 10/64 polaris weightssecondary has a 60/40 notched helix and a red cutler spring in the middle position, the sled would only pull 8100rpm DnD say with the pipes it should be around 8900rpm, I then put a set of 10/62 weights in it and it didnt change the rpm, I then installed a set of 10/58 weights in it that was the ticket. The clutch ingages at 4500rpm tachs out to 8800-8900rpm, then when it shifts it drops to 8600-8700rpm and pulls back to 8900rpm. when removing the shim in the primary you need to grind the edge off the weight where it pivots it hits the ledge in the clutch and doesnt allow the weight to set in the bottom thus in return keeps the clutch ingaged and causes belt creep and when you start it and when you go to stop the engine stalls basically makes the belt to tight. hope this helps you out

 

[KevinS]

<div class='quotetop'>QUOTE (twentybucks @ Feb 15 2007, 08:40 AM) <{POST_SNAPBACK}></div>

I have a 99 zrt800 with ported and polished 900 cylinders and heads, Vforce reeds, DnD 1000 trail pipes, power breather, mbrp can, I removed one shim out of the primary used a factory cat yellow/green spring with 10/64 polaris weightssecondary has a 60/40 notched helix and a red cutler spring in the middle position, the sled would only pull 8100rpm DnD say with the pipes it should be around 8900rpm, I then put a set of 10/62 weights in it and it didnt change the rpm, I then installed a set of 10/58 weights in it that was the ticket. The clutch ingages at 4500rpm tachs out to 8800-8900rpm, then when it shifts it drops to 8600-8700rpm and pulls back to 8900rpm. when removing the shim in the primary you need to grind the edge off the weight where it pivots it hits the ledge in the clutch and doesnt allow the weight to set in the bottom thus in return keeps the clutch ingaged and causes belt creep and when you start it and when you go to stop the engine stalls basically makes the belt to tight. hope this helps you out[/b]

Shim out of the primary or secondary? There are some spacer washers in the primary under the spider but removing the spider is not an easy task.