M&H dot tire wadding up on the launch -please look

[dave brode]

All,

I have a new engine in my truck that I'm trying to sort out. I'm running 29x17 M&H dot tires. http://www.mandhtires.com/store.php?...on=show_detail

I have only made 10 passes, but have always felt a "rumbling" on the launch. Not right away, but through most of low gear. It doesn't blow the tires off, I just feel the tires trying to dig. I had a friend watch closely yesterday, and he said the tire wraps up and plants, but about 1.5 truck lengths out, it wads up and deforms badly.

I have done ok with 12.5 to 16 psi, but it "rumbles" with those amounts . I tried 20, but it spins on the hit. It has gone 1.59 in the sixty, but usually goes low 1.7x. On the pass yesterday with 16 psi, it went mid 1.7x, but the tire was wadded up so bad and bouncing that my buddy could see light UNDER the tire.

I have CE adjustable shocks, rears set on 70/30, fronts on 90/10. On the hit, it lifts front up, a little air under the left, and it seems to be all well until 1.5 lengths out. I plan to try tighter shock setting front and rear.

Do I need a stiffer tire? Thanks in advance for any ideas.

Dave