clutch springs

[rak12]

In general at what RPM's do 3 shoe clutch springs engage vs. diameter?

e.g. .9mm =
1.0mm =
1.1mm =

I know there are other factors involved such as shoe weight, friction on the pegs, etc. I'm just looking for ballpark figures.

 

[ozziii]

Not sure what the actual rpm's would be, but using a thinner spring on a loose low grip surface will help make the car more drivable because the power isn't just kicking in & creating heaps of wheel spin all at once at higher rpm's when the clutch engages.
More surface grip can use a heavier spring as there is less chance of wheelspin at the higher rpm that the clutch will engage at.

 

[rak12]

Thank you for your response. I was fishing for response in hopes that someone may have some ball park ideas. I think this is just one on those things I'll have to play with and try different size springs. I have been running 1mm on a 3 shoe aluminum clutch, but it is a little snappy off the line. I am currently doing my winter rebuild and plan on trying .9mm and see how that does.