CANTONRACER

Has anyone had to actually move the rear end back like 1/2" to allow room tire growth in the high mph range?

timelord

Saw a post by INJUNEER somewhere yesterday that delt with this,he was talking about growth at 130mph needing relocation.5" or shaving of the rear bumper cover by 1.5" depending on kind and size of tire!!!

Can't seam to remember in what post or on what board!!!

Injuneer

With a 28x11.5-15 Hoosier QTP (28.0" diameter), I moved the rear axle back about 1/4" to eliminate rubbing on the front metal edge of the fender opening at maybe 120+MPH trap speeds.

Switched to a M/T ET Drag 28x10.5-15W which is supposed to be 28.1" diameter, but is apparently a bit more than that. I had to cut about 3/4" off the leading edge of the bumper cover just to fit the tire in the opening. Then take another 3/4" off the bumper cover (1.5" total) to keep the tire from rubbing. The last dyno pull the car hit about 130MPH, and I found a small groove in one tire from the metal edge that is behind the rubber bumper cover. I had hammered that edge back quite a bit, but apparently I need to beat it back even more.

This is the ET Drag, with the axle back 1/4", and only 3/4" cut off the bumper cover. You can see how a lot more had to come off the bumper:

http://cjcfo.fbody.com/members/injun.../DCP03451a.jpg