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Discussion Starter · #1 ·
All I recently had to replace a tire due to an impact break(tires had 13k miles). I bought an OEM SP9000 from Tire rack. A local shop mounted the new tire and pulled my spare out. Those two tires are on the rear. I moved the rear tires forward. I put the other tire as a spare. I had the car aligned at the same time to as close to the following specs as possible:

Front
Camber: -1.1 degr both L&R
Caster: 6.2 degr
Toe: 0.0 degrees

Rear
Camber: -1.1 degr L, -1.2 R
Toe: 0.09 degr

I have a 2002 five speed and now the car feels very unstable the higher the speed I go. Car seems to respond well but feels like it is bouncing on air on the left rear which is where the new tire is.

I have checked the direction of all tires.
I have checked the air pressure.

What else should I check? My car was very stable before and now it feels like a minivan.

Thanks Josh
 

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Is your car stock height? If it is, you have too much negative camber. You probably got uneven tire wear which would cause your problems. For future reference, do not rotate your tires, just replace the tires that are worn. Moving the unevenly worn tires from from front to back or back to front will cause the problems you have.
 

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the rear camber is within specs (-1.4 to 0.4) but the front is slightly off (-1.0 to 0). doesn't seem too drastic to give you any severe handling problems though. After I got my alignment done the car did feel a little wierd for a day or two but I soon got used to the "feel" and now it doesn't bother me anymore. May be you just need time to get adjusted to how it drives. I don't know if this is true but I've heard that auto manufactures have tires made specifically for them for the vehicle, so what you can buy at retail might not be what came with the car even if it is the same model of tire. If that's the case, mabe the stock tire was designed for a slightly softer ride.
 

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Discussion Starter · #5 ·
Thanks all,

I have had a couple of days to get used to it. The handling is much more precise than before which makes it seem jittery due to imperfections in the road which are causing some tracking issues. I also think the tires just needed a few hundred miles to get worn in.

The only thing still hard to get used to is now it seems to lean harder on the rear which makes me think I am going into oversteer, but I am not.

Thanks for all the posts. It freaked me out the first couple of times I drove it after the alignment. Guess maybe I overreacted.
 

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Josh,

The reason your car feels so darty and unstable is because of the toe setting. Most autocrossers set toe to 0.0 to 0.125 total toe out. This gives the car a great turn and very responsive low speed feel. It does make the car a bit scary at higher speeds though. The balanced negative camber shouldn't affect the car too much. Typically less negative camber in the rear will make a car prone to oversteer, not more.

John
 
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