Hoosier Radials

[tommy d]

Curious as to what kind of air pressure some of you run in your radial slicks. We have a set of 31.5/13.5 R 15'S and are running them at 14 lb's. It feels like the wheels are rocking back and forth in the sidewalls at the finish line. Someone suggested 21 lb's ? Thanks.

[HR9121]

I typically run 21-23 psi in my 30×9 Hoosier radicals. Have had as much as 28. I would suggest 18 and go up from there until you find a comfortable setting.

[Hacksaw]

I run Hoosier's 32.0/13.5-15 radials. If I get close to 15 lbs, I get a radial wobble. Years ago I tried more pressure, but only made it worse. Seems like the smaller tires can take way more pressure and not show any wiggles. Maybe it's the greater lbs of weight per square inch on the surface area with the small tire. Don't know

[tommy d]

Originally Posted by Hacksaw

I run Hoosier's 32.0/13.5-15 radials. If I get close to 15 lbs, I get a radial wobble. Years ago I tried more pressure, but only made it worse. Seems like the smaller tires can take way more pressure and not show any wiggles. Maybe it's the greater lbs of weight per square inch on the surface area with the small tire. Don't know

Thanks , so do you run less than 15 or more to get away from the wobble?

[tommy d]

Originally Posted by HR9121

I typically run 21-23 psi in my 30×9 Hoosier radicals. Have had as much as 28. I would suggest 18 and go up from there until you find a comfortable setting.

21 is a number we have been hearing. Right now it wobbles bad enough that you can see it from the fence.

[Hacksaw]

I run under 15 lbs all the time. My rule of thumb is....increase the tire pressure until you subject yourself with radial tire wobble....then go lower in psi.

[1320racer]

radial wobble has nothing to due with air pressure and everything to due with track prep and chassis setup.

Oh and I run 21 psi my 32/13.5 radials.

[tommy d]

Originally Posted by 1320racer

radial wobble has nothing to due with air pressure and everything to due with track prep and chassis setup.

Oh and I run 21 psi my 32/13.5 radials.

I think that going from 14 -21 would have to help...no? Only been out three times and this last week was the first for the wobble.

[1320racer]

I posted this photo for a reason. My car was killer at this track/at this race and IIRC, I ran five, 5.60s in a row, won the boggie race too.

Then once the sun went down and the track cooled, it was a different car and I had radial wobble every pass and had this not been an 1/8th mile race, I would have had to lift.

Point being it was the track not my car.

Left that track, made no changes and the car was right back to perfect launches, passes where ever I raced it.

BTW, that was the last time my car has had radial wobble and that was 7 years ago this November.

[tommy d]

Originally Posted by 1320racer

I posted this photo for a reason. My car was killer at this track/at this race and IIRC, I ran five, 5.60s in a row, won the boggie race too.

Then once the sun went down and the track cooled, it was a different car and I had radial wobble every pass and had this not been an 1/8th mile race, I would have had to lift.

Point being it was the track not my car.

Left that track, made no changes and the car was right back to perfect launches, passes where ever I raced it.

BTW, that was the last time my car has had radial wobble and that was 7 years ago this November.

Ok. makes sense as that was the same for us. This past week was the first night time passes and that's when we started having trouble. Thanks for the help.