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Tire Roll

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Old 05-22-2006 | 03:29 PM
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Tire Roll

What's a good way to prevent Tire Roll?

I have it real bad on the rear, especially on the drivers side.

I push so hard my wear marks go beyond the edge.

I tried 32 lbs. cold and 31 lbs. cold all around.

In fact it falls off. You know what happens then. Off the track.

Got new tires and went to 245's.

What do you think?

Go to 255/265/275 and increase tire pressure?

What about a rear tower strut?

How about increasing the tire pressure a couple of lbs in the rear and the off setting the drivers side by an additional lb., just like they do in NASCAR by off setting the tires on one side.

Any good links where I can read up on this?

How much do shocks come into play? They will help, but I don't see how they will stop the tire roll.

It's squirlley. Ja, I know I'm going real fast.
Old 05-22-2006 | 03:48 PM
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I thought you wanted the tires to roll, otherwise how will the car move?

Are we talking autox or track driving? Those pressures are a bit low for autox. Generally, if you're getting rollover you would want to increase pressure and/or add negative camber. What does your alignment look like?
Old 05-22-2006 | 04:03 PM
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your pressures are too low, but rollover on the rear is not all that critical. Front tire rollover is very critical. Camber plays a roll too.

Last edited by TeamRX8; 05-22-2006 at 04:06 PM.
Old 05-22-2006 | 05:04 PM
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i don't know about you. but i am autocrossing with 37front and 39 rear. it feels better than most other pressure sets that i have tried.
i forgot. that is when the tires are still cold.
Old 05-22-2006 | 05:05 PM
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Originally Posted by mp5
I thought you wanted the tires to roll, otherwise how will the car move?

Are we talking autox or track driving? Those pressures are a bit low for autox. Generally, if you're getting rollover you would want to increase pressure and/or add negative camber. What does your alignment look like?
It's Track.

Alignment is stock.

No problem in front. I have under steer with RB sway bar.
Old 05-22-2006 | 07:10 PM
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Originally Posted by Razz1
It's Track.

Alignment is stock.

No problem in front. I have under steer with RB sway bar.
A track alignment and rear tire pressure change would fix a lot of your issues.
Old 05-22-2006 | 08:19 PM
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How about bad springs?

I just found out my springs dropped an inch lower than specifications.

But wouldn't this condition cause more weight in the back end to make it more stable?
Old 05-22-2006 | 09:50 PM
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yeah, at the track I run 40lbs cold on the fronts, 38lbs for the rears cold
Old 05-23-2006 | 02:25 AM
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I'm running 245's at about the same pressures w/o the roll you are experencing. Try raising the pressures 5 psi and mark the tire to see how far they are rolling over, then adjust from there. I would think increasing the width of the tire and staying on 8" rims would make this tire roll easier. Like others have said, a alignment with more negative camber would help.
Old 05-23-2006 | 07:06 AM
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Originally Posted by Razz1
How about bad springs?

I just found out my springs dropped an inch lower than specifications.

But wouldn't this condition cause more weight in the back end to make it more stable?

Yes, you need new springs, and I will have to have those nasty short stock springs for inspection ASAP Seriously, if your stock springs are that low, I will buy them from you and you can take the money and put it towards some aftermarket coilovers, or whatever.

You have a terrible push/understeer condition probably made worse by your RB swaybar if you have none (i.e., no RB swaybar) in the back, the understeer prone stock alignment, and the underinflated tires.
Old 05-23-2006 | 04:04 PM
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The real culprit seems to be the left rear spring. Ride height is 1/2 inch lower on that side.

Not only that, when I put 25lbs in the trunk on that side it even drops further!

Anyone have KW coil overs?

I here some Mazda, Ford and BMW race teams use that setup.
Old 05-23-2006 | 07:06 PM
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I doubt your springs are bad, no way you have enough miles on your car to get spring sag. More like a bad shock. The stock shocks are high pressure and if one was bad you could get that sag.
Old 05-23-2006 | 09:00 PM
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yeah, I would check your stock setup before dropping any money on coilovers
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