Anyone running the MT PBR 32x14 on a bracket car running low 5's or quicker 1/8 mile? I've been trying to get them to work and I have an issue with the car rocking side to side like a boat. It happens mid track and later and gets really sketchy sometimes. I've ran from 9-12lbs of air in them and moved shock settings with no real difference. I'm going to try a different 4 link setting that is a little more traditional radial setup. Any thoughts on how to stop the rocking / wobble?

I don’t know how true it is, but from what I’ve read about radials, you are a good five to six pounds too low on air pressure.

I tried 13 and it blew the tires off instantly, so I'm going to try a 4-link setting that will drive the tire into the track so I can try going up in pressure. At 12 psi seems like the outer edge is not really on the ground but they are kink of build that way it seems like.

Our car did that once real bad. Not with PBRs but it turned out to be a bent wheel. Jack it up and setup a gage and make sure wheel is running true. Ours was bent just a little and it made for some sketchy runs.

May have got bent mounting the tires.

Have you checked your tire gauge lately against another "known good" unit?

I have a friend with a set of the big radials he couldn't make work, went to bias tires, couldn't make them work, checked gauge and it was reading about 8 - 10 p.s.i. low, set tires with good gauge, it has printed tickets since.

It didn't do it with the bias tires on them but I do have another set of wheels I could try. They are beadlock wheels.

quote:

Originally posted by ski_dwn_it:
Our car did that once real bad. Not with PBRs but it turned out to be a bent wheel. Jack it up and setup a gage and make sure wheel is running true. Ours was bent just a little and it made for some sketchy runs.

May have got bent mounting the tires.

I have 3 gauges all read within .1 psi of each other.

quote:

Originally posted by Goob:
Have you checked your tire gauge lately against another "known good" unit?

I have a friend with a set of the big radials he couldn't make work, went to bias tires, couldn't make them work, checked gauge and it was reading about 8 - 10 p.s.i. low, set tires with good gauge, it has printed tickets since.

I talked to Mickey Thompson today and the guy asked how they balanced. They took 15oz on one and 8 on the other, he said that is way too much. I don't think that is a factor as it's not a vibration but more a wobble/rocking. Also said at my weight start at 8psi and go up until the 60' slows then back down one step.

quote:

Originally posted by inferno camaro:
It didn't do it with the bias tires on them but I do have another set of wheels I could try. They are beadlock wheels.

quote:

Originally posted by ski_dwn_it:
Our car did that once real bad. Not with PBRs but it turned out to be a bent wheel. Jack it up and setup a gage and make sure wheel is running true. Ours was bent just a little and it made for some sketchy runs.

May have got bent mounting the tires.

Ours started after a tire change. Assuming the mounting bent them or because it was dead hooking it did something to the wheels and bent them.

Got new wheels and same tires - perfectly smooth sailing.

Its easy enough to check. Jack car up have someone put it in gear. Rig up a stand with a screwdriver close to the wheel and if its moving in and out at all - that is your problem. Its shifting the weight of the car back and forth and it gains momentum and violence as it does it.

If that shows good runout, see if the tire itself. I would expect some on the tire, but not the wheel. If its excessive on the tire it might cause it.