I am thinking of running a street class for labor day weekend and have to switch my tires to mickey thompson drag radials. I have never ran drag radials so I have no idea where to even start with the air pressure. I am running alot smaller tire so I might have some hooking issues anyways. I am going from hoosier QTP 28x14.50x15 to a mickey drag radial 275-60-15. The car hooks really good with the QTP's at 13.5 to 14 psi.

the best place i know to start from is..
find a place to safely spin the tires..
like an industrial complex ect...if you do it on concrete thats even better..
find a clean section of road surface
and do a light burnout..spin the tires while rolling out.
then get out and look at the imprint on the ground..
you want as wide as possible of an inprint.
with an even coloring as it moves to the center of the marks/patch.
if the center is much lighter than the outlines..
then you need more air...add 1/4 to 1/8h pounds of air and repeat..

if you have a dark center of the patch and it fades as it reaches the outer edges..you have too much air..
lower in the same amount..
you are looking for a evenly dark patch across the entire black mark left on the ground.
once you have this jot down all of your psi's
this should give you a really good base to work/start from
right down your psi's and temps if you have that tool...it helps alot.
and start at that point at the track..
thats what i would recomend...
this works for slick tires too..
cheapst

What width rims? On 8", I'd start that size ET Street Radial at 19-20 psi. I know that anything less than 17.5 psi on my Challenger folds up the sidewall too much and your car's gotta be putting more weight over the back end.

They are on 10" wheels. car weighs 3800 lbs with me in it.

At least 20...

I ran the hoosier 275's I was at 19 psi

1.37 60 ft 3480 lbs

Looks like I will probly start at 20 and see what happens. Thanks for the advice. I am kind of in the dark on this one. I hope they they stick. Just looking at the results there was only 12 cars in the real street natrally asperated class and they give jackets up to the number ten spot and I also get to do the cruise laps around the road course to prove the street car thing saturday night which I have wanted to do for awhile. I cant wait!

Drag radials are more sensitive to proper chassis setup and track prep. You can be "off" some on setup and running on a so-so track w/ bias-ply slicks and still hook up OK, but simply swapping to drag radials under the same conditions will be disappointing.

The good thing about this class is it is the five fastest classes for the the show so befor these classes the track get a complete prep. Traction compound all the way down, This is the best the track gets. This is at muscle car shootout at Brainerd international raceway. I did try a couple suspension changes, I hope they work!

I have BFG's on mine...I know its not the same entirely...I have an 8.5" rim and I tried all the way down to 17lbs and I was still not hooking ...so I did what they say not to, I went to 14psi and it hooked hard for me at a 6500 launch...

on the street I inflate at 28psi and hook on the street...Cal-Tracs work good...

16.5 but do not tell anyone

17 psi

18 1/2 psi on my 68 satellite,8"rim

Tex