Well, I have a thought,... if you lower pressure the contact patch gets longer. More of a "tangent" if you will area between the track and the tire, you can actually watch that area get longer as you reduce pressure. Not sure what that means and how that and cupping interact. I am like 440Jim, a bracket racer which my thinking is trying to get close to a dead hook to make it the most consistant. I run about 9 lbs in a 14-32W-15 on a 15" wide rim with a heavier much less powered back-halved 4-link car which probably means absolutely nothing in this situation. But thats what I run anyway.... Good Luck