My car is totally stock with slightly modified UK alignment (-1.2 front camber and -2 rear camber) and race pads. I have been running with on stock AP1 wheels with street tires (205-245) for a while now and came across a cheap used set of wheel that I plan to use on the track. The rim size are 17x7.5 +45 front and 17x8 +45 rear.

My plan is to run 205/50/17 RA-1 front and 235/40/17 RA-1 rear. Anybody know how those combo with work? I know that Toyo has 235/45/17 RA-1 also but I don't know if it will be too tall for the rear wheels that I bought so I don't know if I should get the 235-45 or 235-40 for the rear.

 

I decided to go with 235/40/17 for the rear. Just ordered them today shaved to 4/32" so we'll see how the 205/50/17 front and 235/40/17 rear will do at the track.

My guess that this set up should be fairly neutral with a slightly oversteer. So if anyone has any comment and input on my alignment and tires and wheels set up let me know.

 

Sounds like trouble to me. I doubt you'll be able to get the car to be all that fast with that stagger. I suspect the rear contact patch will be too small considering it's smaller than stock. A rwd car that oversteers at the limit is a lot slower than a car with slight push at the limit. Slight push is what you want in steady state mid corner. It allows for getting on the gas sooner on exit.

 

Oh, regarding an alignment to help with this stagger, I'd run maybe 1/4" total toe-in in the rear and as much negative camber as possible. At the front, I'd try zero toe and about -1.4* camber.

Good luck

 

I should mention that several of us track junkies here in Cal are running equal tires front and rear with success (thanks to Maxrev for breaking the norm here and following the Japanese). The only thing in common with the cars is they all have a wing. Suspensions and spring stagger range from stock suspension to full race with more springs front to more springs rear. I'm beginning to think that the "oversteer if you don't have enough tire stagger" is a myth.

BTW, I believe those 235 40 17 are wider than stock, but an inch smaller in diameter. I got them delivered once by mistake, They are wider than the 235 45. The rake of your car will change because of the different diameters front to rear.

 

The only issue I would have with that is that it's just less rubber on the road, both front and rear, than I would consider ideal. I doubt that the stagger is a big deal (if anything, the stagger strikes me as favoring understeer over oversteer, with those tiny front tires and fairly significant rear tires), but I think that you're giving up a fair amount of traction with those sizes.

 

I understand that 205 front might be a little under size but with 205/235 combo it might not be too bad. Putting the wheel width aside (since my track wheels are different in size compare to the stock wheels), I ran 205/245 combo on the stock AP1 rims for a while and with the 205/245 Hankook RS2, it is about as wide as the 205/235 RA-1 (maybe the rear are slightly smaller than the RS2) and with the added grip of the RA-1, it might be okay as far as the traction is concern.

 

I think you'll be "ok" as far as the traction is concerned; I'm just saying that you're using less tire than is optimal, so that you will have less traction than if you had wider tires. That's not a deep statement, I know, but that's all I was saying. I use RA-1s also, on stock AP2 wheels, with 255/40-17 on the rear wheels, and 235/45-17 on the front. Heck, in autox, I use 245/45-17 Kumho V710s on the front, and 275/40-17 on the rear. I like traction.

 

[QUOTE=rlaifatt,May 4 2006, 07:30 AM] BTW, I believe those 235 40 17 are wider than stock, but an inch smaller in diameter.

 

Yes, rake is the slant of the car. With these your rear will be lower than before, and you speedometer will be off slightly too (reading higher). Probably not a significant effect overall, but let us know how they work out anyway.