Thread: Indy 500 power
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Old 01-27-2016
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Join Date: Nov 2007
Location: Alexandria, MN
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Originally Posted by SnowMO View Post
I have a Question about the spring in the secondary Clutch on the helix. There are four holes to place the spring in to, I changed the hole it was on to a different one now it seams so much more quicker off Acceleration. What is the difference and does it affect performance or top speed?
I don't remember for sure which direction to move the spring to achieve it, but moving the spring to a different hole changes the preload on the torsional movement of the spring. A tighter preload will slow down the upshift, so the sled will build RPM more quickly. At the top end, a tighter adjustment adds RPM. Moving four holes will add approximately 250 RPM at the top.

When you reassemble the clutch, remember to preload the spring before you install the snap ring. The back, or moveable sheave, needs to move 1/4 turn counter clockwise before you push the helix down to get the snapring in. Just use common sense to figure out which hole in the helix puts more pre-tension on the spring. I haven't had a button clutch apart for quite awhile, so I don't exactly remember how things line up in there. All I remember is that if you don't preload the spring correctly performance is terrible.
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