The stock Sidewinder helix is 35 degrees. It matches the flat profile of the primary weight. The ramp is very long and the helix moves a long way during shift out. When you install a stiffer spring, the helix moves so much that stiff spring really gets wound making it stiffer still. By taking a dual angle helix such as in my case a 45-41., the ramp is much sorter letting the stock spring to work as designed.
When choosing the helix angle for my SW, Mr. Lessard took into consideration the profile of the primary weight I was using. He then chose the helix angle to match the shift profile of the weights.
When you run a super stiff secondary spring, you slow or hold the shift of the secondary and loose clutch efficiency creating heat. You are using engine power to open the clutch instead of using power to move the sled forward. You want the primary and secondary shift rates to MATCH each other, not fight each other.
It seems that a lot of people here are clutching sleds for the first time, which is great. I love trying to make the clutches on my sleds work perfectly, it is half the fun of snowmobiling to me. BUT, remember that with the power of these Sidewinders it is easy to mask clutching inefficiency's. These sled will power right through some improper set ups. Try setting up a 60hp sled first , where every little change can be felt, good and bad.
Don't copy some one else's set ups, use them as a reference . Try things your self and get the sled to drive the way you want it to drive.
For what is worth, the world fastest sled uses a stock Apex secondary............
