Clutch confusion

[TravisFader]

Ok so a few questions for you smart guys out there. I have a 04 Viper and i dropped about 5 grams each weight in my primary getting ready for the mountains. This increased my engagement RPM from 4200 to 5000. Should not a lighter weight make my engagement RPM go down thus making it easier to turn the track in the mountains? Do i want my mountain clutch setup to engage at a high rpm or a low one? Soooo confused here. any help would be greatly appreciated. Does 5000 rpm seem like the right engagement rpm for the mountains?

[magnet]

A lighter weight will make engagement go up as your clutch works on centrifical force. Faster/ heavier it spins sooner it engages. however your spring tension also makes a big differance. As for the 5000 rpm lock up for mountains i would think it would be good for you but i am no expert on it.

[NM]

Originally Posted by TravisFader

Ok so a few questions for you smart guys out there. I have a 04 Viper and i dropped about 5 grams each weight in my primary getting ready for the mountains. This increased my engagement RPM from 4200 to 5000. Should not a lighter weight make my engagement RPM go down thus making it easier to turn the track in the mountains? Do i want my mountain clutch setup to engage at a high rpm or a low one? Soooo confused here. any help would be greatly appreciated. Does 5000 rpm seem like the right engagement rpm for the mountains?

More weight on the toe of the weight = higher engagement or less weight on the heel of the weight will do the same thing. I assume you removed a rivet from the clutch? Try and weight your weights so you have more of the total weight to the heel. More weight on the end is better for drag racing...not so good in the mountains. Might be time to buy a new spring too. Any yammie dealer should have a high altitude recommended spring for your setup.

[TravisFader]

i went from 8dn 10's with a 4.5 gram weight in each riven hole to 8dn 20 with a 4.5 in the toe hole, Your saying that the rivet should be in the heel toe for the mtns? Does it make that big of a difference?

[NM]

It makes a huge difference. You wouldn't believe it until you try it.

[TravisFader]

we talking different RPM? Just plain better in the deep stuff, so what i should do is drill out the tip weights in my 8dn20's, get a new set of 4.5's and put them in the heel's? And that'll make it better in the powder? Im taking my first trip to the mtns pretty well the first trip of the season so i dont want her to be a dog in the snow you know. Last year i just couldnt get the rpm and power to keep going in the deep stuff

[NM]

If you change the weights from the toe to the heel, it will come in at a lower RPM and it will rev out a bit more. If you still can not get the Rpm then you may need to drill all the rivets out. Make sure you have the right setup in the secondary as well. You should have a really stiff spring and probably a 47 deg helix or somewhere in there. Longer track=less helix deg.

[TravisFader]

Yeah ive got a pretty long track, its a 159. I have no clue what my helix is or anything. I just wanted to change my weights for the mountains and 5000 rpm just seemed pretty hight for the clutch to engage. Which is why i was concerned. But i guess i wont know until it hits the powder right.

[mb1]

I'm no expert but I think you should be more concerned with the RPM your engine will hold when you're WOT in the deep stuff. Only thing is it's impossible to tune for it unless you're there. You can't tune clutches on a trackstand because the secondary sees no load and therefore everything is wacked out.

Good reading. Tuning Applications

Try to find someone who's run a setup like yours in the past. Might try the other site there's simply more users there. snowest. Good luck.

[mb1]

might be a better read.

Snowtech Magazine - Snowmobiles, Snowmobiling, Snowmobile Techncial Data