Horrible handling

SPOHN

Went to the track yesterday and only ran one session due to other minor issues. But even if that wasn't the cause the handling would of made me stop.

Normally I run -2.5 camber -.02 toe on front and -1.8 camber 0 toe. Well I was telling my alignment guy about the mild bump steer our cars have and he felt running some toe in would help this cause and give more rear traction. First let me say the guy knows his stuff in this area. Wouldn't trust no one else so let's not go there. So he added .08 toe in which at the time I really didn't want that much but let it ride. Well come yesterday on the track it was the most horriable rear handling car I ever felt. I did not feel like going over 40mph around turns for it was that bad. The front was planted but felt as the rear was on ice the hole time. Very loose. The rear was steering the car bad IMO. Nothing else was changed on the car besides the traction arms but I dont see where's that's a issue. Maybe I should take the sways off full stiff in the rear. But there's no doubt I'm going back to the alignment shop and get this undone ASAP.

I talk to my guy today and he doesn't feel that should of been the case at all. He feels there should of been more traction added. So any input guys? I know our cars are far different from other. I don't want no slander on my guy. I trust him. It was definitely a trail and error. I also have always run a true type coilovers no issues. I now have SPL traction arms going on the week to help with bump steer by eliminating the crappy rubber bushings.

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VoBoy

Probably takes some time to get use to... Toe-in in the rear is generally the standard for RWD and helps with high speed stability. Heck toe-in in the back comes stock.

SPOHN

This is not a getting used to situation. I know how my car was handling and I know how one should handle and this was nasty. It was pushing in the rear while the front was behaving perfect.

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cdoxp800

Chris you think it could have anything to do with the crash at Road Atlanta? I know you took allot of damage to the read of the car.
I don't feel .08 of toe is going to cause that issue, but you never know. Just set it back to zero an give it another try buddy.

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SPOHN

The frame machine came back dead on so there was no pulls made to the sub frame/ unibody area. The alignment was hardly off. I haven't been on the tack in close to four months. I am running on new tires with about 800 miles on them. Maybe it's me. My nerves were shot trying to get back into the feel of it all. But even then I didn't feel right.

I talk to my buddy Mike and he feels also the toe maybe the issue along with the sway being to stiff. The turn in felt great but the exit of all turns felt slick. Maybe the tires need more time. Just trying to get different views here.

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M.Bonanni

I highly doubt the toe-in was the issue unless he accidentally went toe-out. You say you did or did not change the traction arms prior to the event? If you did, that's likely the issue as they can affect bump steer. Where exactly was it loose? Entry? Mid-corner? Braking? Exit? All of the above? If you answered all of the above its most likely a toe situation unless there is something mechanically wrong/broken that you didn't notice.

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SPOHN

Most felt mid corner and exit. Maybe the tires need more time on them? The spring percent got missed up pretty bad but it seems correct. The thrust angle is good also. I'll have someone else drive it to see its it's in my head. I changed the the camber arms and toe arms before last alignment. This week I'm installing new traction arms. All through SPL. Maybe it's me. The tires are hardly broke in. The hole course was a off camber track. Never done that much. So I'll keep a open mind. Maybe my accident has me mind boggled.

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threeseventy

Way too much toe in up front. Not enough in the rear. .010 toe out in front, (.020 total) .025 in on the rear. (.050) Camber seems about right for the front, consider less in the rear, these things go negative camber very fast in back once the compression starts, I actually dial some camber out so when I'm fully compressed they're around 3 degrees neg. and wear patterns are near perfect.

Oh, and definitely soften up the rear camber.

Now- how was the Fuel Starve fix?

M.Bonanni

You just changed rear tires? Street tires or race tires? Same brand/model/compound as the front? That could be the case. Was it only when turning a certain direction? When the rear broke loose was it snap oversteer or gradual/controllable? Was the turn-in good because the rear rotated easily or because the front was sharp? How was it under braking?

If it was indeed driver error it was likely a case of going too slow in and getting on the gas too early/hard. Without messing with the traction arms/toe curve I am going to say it's likely not due to the small toe-in.

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SPOHN

Same tires front and back. AD08's. It was gradual and controllable. The turn is was what seem sharp and rear rotated easly. I was running a 265 up front went to a 275. Braking was more than fine. Maybe it's such a dramatic change on all levels that made it feel wild. I was definitely slow in a trying to push it out hard. I guess my nervous are a wreak from my incident. I've been beating myself up for months about it so........

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M.Bonanni

I am going to go ahead and guess that its a combo of getting on the the gas too hard/early and rear sway was too stiff for the new setup. Toe issues usually end in a more snap-oversteer or unpredictable feeling. I don't think it was the tires. The AD08s are actually best on their first heat cycle. Race slicks when cold/brand new can be a handful but usually not true for street tires.

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SPOHN

Sways are on full stiff now. I'll back them down check my alignment again in case and grows some balls. Lol. Thanks for the advice Mike.

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SPOHN

I also assume that going with the SPL arms and how they do away with the stock rubber bushings and going with solid mounts had to create more stiffness and teamed up with all my other suspension parts I already have on top of all the weight I've removed back there has pushed it all passed it limits.

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takjak2

Let's just be clear that toe IN tends to make the rear more stable. Toe OUT allows the wheel's slip angle to describe a turn and increases turn in grip (weight transfer will scrub some of this out). See DG's "autocross to win" link Jordo recently posted.

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SPOHN

I think there might be something else to consider at play also. Didn't think about it till later. I don't really wan't to go all into it. But may have something to do with fluid getting on my tires. More details tomorrow.

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