Thanks for the formula, I adjusted it by figuring in rear tire growth. If the rear tire grows 1", which is probably conservative, the slippage jumps to 15.04966. Ouch!

I may try a new PTC. Have been hearing good things about them. Probly have to wait a couple weeks or so, totally tapped out on race car money right now.

[image]http://s1126.photobucket.com/user/nhramark1/library/Racing[/image] 9.100 @ 150 mph 5.780 @ 120 mph