Hoosier Radials

[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.

[Ed Wright]

I don't know what width wheels you have. I found my 13X31" Hoosiers hooked harder, and felt more stable on wider wheels. Went from 12" to 14" wide wheels, no more wobble at all.
Then, I bought a second set of 14" wheels & bought a pair of MT tires, same size. A-B-A testing during a track rental showed the MTs 5 hun quicker, close to one MPH faster. I use 13 to 15 psi to help corrrect my lights. Both dead hooked, I'm thinking the time differences were maybe sidewall design?
Been so long, I don't remember how much air in the Hoosiers. Have run the Mickeys as low as 12, still no wobble on the 14" wheels. Both brands of tires left better foot prints on 14" wheels.

[nhramnl]

I've experienced radial wobble, and as a result, studied it intensively, looking for a cause. Much as I hate to say it, Ed Bigley is probably the closest to what I've learned. The prevailing theory is that the car does not come down from the wheelstand entirely evenly (i.e. one front wheel touches before the other) and that sets off the rocking motion, which gets worse as you progress down the track. Here are other things that affect, but do not eliminate it: shock settings (tighter shocks on the rear tend to reduce it); track prep (as Ed mentioned), but for me, it had a VERY minor effect; and finally, tires themselves. Hoosiers are "credited" with being the most susceptible to wobble, Mickeys are supposedly better and Phoenix allegedly won't wobble at all. The tire pressure everybody talks about for a relatively big tire is 18-22 psi.

[Ed Wright]

Mine does some kinda big wheel stands at times, and neither that, nor different (or lack of) track prep, ever effected the "Hoosier wobble". Wider wheels stopped it all anyway. Before I had it back-halved at EastTexas Race Cars I ran 9" tires on 10" wheels. Then mini-tubed it to run 10.5" tires. Those liked 12' wheels. I loaned my 13" Hoosiers on 14" wheels to a friend that was having "the wobble", and it stopped his too. He now has wider wheels & no wobble. He still uses Hoosiers.