mts

I got the S2000 on the track for the first time Saturday. It's a track I've run on several times before with different cars, but the first time with the S2000.

The car is pretty much stock with a hardtop and Avon Tech RA's (225's on the front and 275's on the rear). The car performed beautifully and was a lot of fun.

There were only a couple issues I need to work out. First, the car really seemed to have a big gap in gearing between 3rd & 4th gears. 1-3 didn't seem to have that gap, but it was really tough to keep the car anywhere close to it's powerband in 4th. It may have just been the speeds I was running on that particular track. I'll have to do a search on this.

Second, the car really wanted to come around on me if I got the throttle down too quick in the corners or if I hit even the slightest bump on an off-camber corner. I let a professional driver take it out (never driven an S2000 before) and he spun it on the second lap in an off camber corner. I also had a design engineer from Koni driver and he too talked about how spooky the rear was under certain circumstances. I just got an alignment done so I'll have to do some reasearch on this one as well.

Overall it was a blast. I can't wait to get it out again.

rlaifatt

Sounds like an alignment issue as 225 front/275 rear should understeer excessively, not oversteer. Toe should be zero front and 1/4" (as low as 1/8") total toe-in in rear; rear camber -2* or more.

mts

I just checked my alignment specs and it sounds like my rear toe may have been a descent size problem. My specs:

Front toe - 1/64 in
Front camber - 1.25
Caster - 6.0
Rear toe - 1/16 in
Rear camber - 1.75

She sees more street time than track time so I was not going for a full track set-up, but it sounds like the rear toe was an issue.

TubeDriver

Add more neg camber at the rear. It won't kill your tires if you run -2.25 to -2.5 in back with a bit of toe in.


AP2 is pretty stable compared to AP1 and with your 225/275 stagger you should NOT have any oversteer problems. What kind of tires pressures were you running?

mts

[QUOTE=TubeDriver,Aug 8 2006, 05:19 PM]
AP2 is pretty stable compared to AP1 and with your 225/275 stagger you should NOT have any oversteer problems.

TubeDriver

front and rear? Try staggering your pressures with about 5 lbs more in the fronts.

I have not used the Avons but maybe see if low/mid 30s rear and high 30s front works better.

alvanderp

I presume you are saying it has 1/16th of an inch of toe-in in the rear? Hard to tell from your quote.

I run 1/8" toe-out in the front and 1/16" toe in in the rear at -1.9 deg camber all around on my car, and I was just at the track this weekend and it was quite benign on 245/275 V710's. Granted I also have the Comptech front bar. But with less front tire your results should be similar. I would check the tire pressures for sure - I was running 35f/34r psi hot on the V710's and it felt perfect.

RSXLNT

More pressure in the fronts reduces oversteer? In my old FWD car, we used to reduce pressure in the back to induce more oversteer - which would be the same thing. I'm sure you're right, I just don't understand. Thanks in advance for any 411.

TubeDriver

I think you should reduce your pressures a bit. The rears can have very low pressures without rollover on the tires I use (Hoosier A6, RA-1, and Victoracers) but the fronts do need a bit more in order to keep the sidewall from rolling. You want the lowest pressure possible in the rear (without rollover) probably around ~low/mid 30s HOT and more pressure in front ~high 30s.

Increasing front pressures will often reduce grip and help balance out the oversteer you describe.