Wondering how far we're off running about 14psi in a friends 28x9" slick? if it makes any difference we're at about 2900lb race weight (i think), footbrake car, stock suspension, has boost n stuff. What say ye?

My MT 9x28 liked 12.5 on slippery tracks. 14 would be better for et as long as it hooked. So if your hooking keep it there.

I'm sure mine isn't nearly as fast but it likes 16lbs. These are Hoosier 28x9. Weight is at least 3800.

Last year testing my friends 64 Polara with a Go=Pro video reveled the tire was being crushed. After shock adjustments we continued to add air. The car weighs 3775 and now runs 17psi on 9x28.5 went from 10.90's to 10.60's
Doug

Go to your local scales.. weigh the whole car then roll
the fronts off and weigh it again so you have the front
and rear weights... the rear weight will help a lot on
figuring many different things.. how high is the boost
at the line...make sure the front has the travel and has
good adjustable shocks... what T-bars are in it.. on the
scales.. make sure you see it at zero before pulling on

My new pic from the last outing shows the tire gettin killed at 12 lbs so this is a good idea about adding pressure that I need to try next time out............

I used to know how to post up pics, anyways not my car i've just been driving it. seems like he says its close to 50/50 weight. motor is moved back some. boost at the line isnt much, comes on quick tho. pro-charger system and blow thu carb. when it only made about 9psi boost it would pull mid to upper 1.30's 60. now more boost 60's are mid/low 1.40's i think iirc ... something like that