New understeer problem

[Topless]

A little background first:

98 Box 2.5L, 75k miles, tires PS2's 225/45/17Front, 255/40/17 rear, performance alignment Camber -.7 deg. Front, - 1.4 deg. rear, zero toe front and rear. Two years Auto-X / track experience.

Last year in Oct. my rear tires were down to the wear bars, lap times were suffering a bit and I had a few spins on corner exit with snap oversteer on rough surfaces. The tires were actually 4 years old and I figured the rears were toast. Front tires were only 1/2 gone and still felt ok. I put new PS2 rubber on the rear and added a lower stress bar to reduce chassis flex. Now the rear of the car is completely predictable. I feel I can put the rear exactly where I want it with my right foot and no surprises. I am carrying higher speeds and some high 2nd gear turns are now moderate 3rd gear. So far so good.

The problem:

Now on downhill off camber turn in's and carousel turns she plows like nobody's business. I feel like I am crawling through these sections. Even if I really pitch the rear out the front just howls through. I am turning faster times. It just looks and feels really stupid when it plows.

Possible solutions:

A. Learn how to drive. :lol:

B. Lose those front tires cuz they're 4 yr old hockey pucks.

C. Add a front strut tower brace to balance front/rear chassis stiffness and precision.

D. Fine tune the alignment.

Anything I am missing here?? Your input is appreciated. The more track and Auto-X experience the better.

Edited May 17, 2008 by Topless

[kabel]

I'm no expert, but a guess, your skill level and confidence has increased and now you may simply be carrying too much speed into those turns. Plus those front tires could be heat cycled to death, but if you keep 'pushing" through those corners you'll need a new set in no time! :lol:

kabel - who wishes he had your problem, he only autocrosses :P

[boxs2000]

I'm no expert, but a guess, your skill level and confidence has increased and now you may simply be carrying too much speed into those turns. Plus those front tires could be heat cycled to death, but if you keep 'pushing" through those corners you'll need a new set in no time! :lol:

kabel - who wishes he had your problem, he only autocrosses :P

[/quote

I too have felt the huge difference of the rear lower stress bar and I agree with you about the front plowing more. What I'm going to do is either go with a slightly wider front tire or a 5-7mm spacer.

[Topless]

Thanks for the response guys. Definitely more confident now. My brother and I do a little tag team on the track. Some areas I am faster, some he is faster. In the downhill off camber he just had a lot more grip and pulled away. He is on fresh RA-1 tires though. Now to get balanced again.

[Topless]

Ok, it seems the consensus is to put fresh tires on the front to match the grip in the rear. The old PS2's are just fine on public roads but protest too much when driven hard around the track.

So now the $$ question: Do I put a new set of PS2's the same size 225/45/17, upsize to a PS2 245/40/17 or go with a little stickier tire like the Advan Neova in 225/45/17? Any thoughts? Front wheels are 17x8 so both sizes would fit.

[kabel]

well my limited experience (i.e. no track - only autox) the plus size up front helped reduce some of the understeer. Plus it seems difficult at times to find the 225 in the PS2. I have also heard really great things about the Advans, but if you go that way I would think you should buy them all around and not mix.

[topmech0]

well my limited experience (i.e. no track - only autox) the plus size up front helped reduce some of the understeer. Plus it seems difficult at times to find the 225 in the PS2. I have also heard really great things about the Advans, but if you go that way I would think you should buy them all around and not mix.

i know this probably goes against the grain but by stiffening the rear even more should help the understeer but definately tyres first!!

[Topless]

Kabel,

I think you are right. Sticking with PS2's all around will give the most consistent balance and handling. That is more important to me than ultimate grip right now. Changing to a stiffer rear sway would probably also help but it would cost too many points in my class. Trying to stay in street stock for the season.