The most common problem I know of is incorrect tire pressure. As you indicate you got new tires I would start there. I seem to recall running 32 front 34 rear for S02 many years ago. Under inflation of the rear will definitely exaggerate “step out” which is what it sounds like you are experiencing.

Utah

 

Reduce rear Toe

 

Thanks all. I took it for a drive earlier and "nervousness across midcorner bumps" sums it up. Going off throttle through a corner I can feel it, but I think it was that way before. Now bumps through a corner are what really get it.

I didn't notice this so much prior to the tires / alignment. The previous alignment spec was .50* total, which is around .21", close to where it's at now.

Could the change in tires be what I'm feeling? I had Hankook Ventus V12 evo2 tires before, but they were cracking.

Otherwise is it safe to say that this is normal handling for an AP1?

From what I've read increasing rear toe helps improve stability... and .24" is within factory spec. What will reducing it do?

 

The AP1 has a lot of positive toe as part of its spec.

Since your car is lowered, it may be a good idea to reduce the amount of static toe (straighten the tires out) a little.

I would opt to have maybe half the toe you have at most.

 

Definitely nature of the beast...butt clenching nature. What size tires are you on? I kinda miss it actually. 205s/225s will keep you on your toes. Be smooth, limit rear toe to 4mm total and don’t lift. A soft tire wall will exacerbate this issue from my experience.

 

Bushings should be inspected too. I will have MUGEN bushing sets coming next month. What is the mileage on the car?

 

Around 140K on it now

 

You should inspect all the engine/transmission/differential mounts/bushing at this high mileage. They probably have some cracking/breaks.

 

When I get a rear-end wiggle on throttle or engine braking, the first place I check is to make sure both rear tires are at the same PSI. The Torsen diff is sensitive to tire radius.

--Carlos V.

 

Ah, you describe how the stock ap1 feels.

bumpsteer kit removes that wobble completely.

otherwise, reduce the static toe.