Dano
TY 4 Stroke Master
I've bought allot of clutch kits throughout the years and I'm not going to say their is no gains. However, the stock clutching can also be calibrated and fine tuned. Again, its all what your looking for and what your willing to trade off. I have well over 20,000 kms on my Apex and can say most of that was in front. I don't have the fastest Apex, but I'm far from being a slow ride. Still have stock clutches and components with small mods in secondary and 2 different springs. My Nytro just rocks so far and not really sure where I can gain. If I have 130 hp, I'm not going to try and clutch it to beat a 150 hps sled when the same rules apply to other sleds.
Dan
Dan
Essarex
Pro
I agree with michvector and dano. The post originator admits little to no knowledge in clutch tuning. He is best to leave the stock calibration alone. The OEMs leave very little on the table in their calibration of top performance models (Apex, Attack, see his garage signature).
It is impossible to get an optimal state of tune in your clutches. As the sled operates through changing surface conditions and temps/pressures, the clutches will provide varying degrees of power transfer. Someone in this thread has already mentioned that committed racers will change the tuning many times during the day, to match conditions.
Have you ever watched a clutch shift out while the track is off the ground on a stand? It will hit the fully shifted out overdrive ratio 1000s of rpm below the power peak. Why? No torque feedback through the helix. The opposite is also true. Grab a bunch of brake while nailing it, and the engine will go to peak power without any shiftout at all in the clutches. (not recommended)
No one will disgree that clutch tuning will add performance, but what works today will not work tomorrow, if tomorrow''s conditions are different that today's. The point of michvector and dano is to not send this new guy on a expedition he is not prepared to take.
It is impossible to get an optimal state of tune in your clutches. As the sled operates through changing surface conditions and temps/pressures, the clutches will provide varying degrees of power transfer. Someone in this thread has already mentioned that committed racers will change the tuning many times during the day, to match conditions.
Have you ever watched a clutch shift out while the track is off the ground on a stand? It will hit the fully shifted out overdrive ratio 1000s of rpm below the power peak. Why? No torque feedback through the helix. The opposite is also true. Grab a bunch of brake while nailing it, and the engine will go to peak power without any shiftout at all in the clutches. (not recommended)
No one will disgree that clutch tuning will add performance, but what works today will not work tomorrow, if tomorrow''s conditions are different that today's. The point of michvector and dano is to not send this new guy on a expedition he is not prepared to take.
Essarex said:
This is precisely why I told the OP to buy Olav's book. His post was asking how to learn about. We can all argue wheter clutching works or not but I can tell you it does, but only in the right hands. Or with a company this is will to take your calls and help you get the best out of your sled. When you add aftermarket clutching, or tune clutching with stock components, if you dont address traction and transfer you will most likely go backwards. Meaning, you will blow your track out (spin). Sure there will be days when you have perfect condtions and hook up, but Ill tell you right now, if you clutch, you must also address traction and transfer. Period!
FireStone
Pro
I recently try the Dalton billet ajustable flyweights model QAY-62 with the green-grn-grn spring and the Helix Dalton 50/46. I did a rought adjustment to begin. It kills a stock Apex by 4-5 lenghts. We try 6 times. We open trottle at 20mph and 40mph. It rev quick, backshift is a bit better. But it needs some fine tuning.
And I did 187km/h GPS but I finished the rpm a 10100 with the helix at 6-1.
Flyweights are a bit too loaded. And after some tuning if it wants too over-rev, I will put the helix at 3-3.
Make some tries and find the best for you!
Any sled are different, Gearing, track, weight....
And I did 187km/h GPS but I finished the rpm a 10100 with the helix at 6-1.
Flyweights are a bit too loaded. And after some tuning if it wants too over-rev, I will put the helix at 3-3.
Make some tries and find the best for you!
Any sled are different, Gearing, track, weight....
Gear to speed calculator. If you want to see what gearing will do to your top end check this out. Remember clutching will most likely have to be tweaked as well to see the results of gear change.
http://www.totallyamaha.com/snowmobiles ... tches.html
http://www.totallyamaha.com/snowmobiles ... tches.html
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