My car is only used for Autocross. Can anyone suggest alignment /ride height settings. I compete in SCCA ASP class and as such cannot chip the car. Will higher octane help out with a stock motor? Details:

H&R coilovers (on the way)
B&M shift kit
Hoosier 245 A3S03 Front
Hoosier 305 A3S03 Rear
Lowest part of the car is the after market trailer tie downs
I trailer the car to events so.... the chin spoiler on driveways is not an issue

Thanks guys!

 

Watch for the rear tires rubbing on the inside wheel well at the
lower back. Allignment is a tradeoff between being able to brake
heavily (wants the wheels vertical on the straight versus being
able to corner hard (which wants the wheels tilted in on the
straight). I would recommend anything in the range of 1.5 to 2.5
degrees negative camber all around, depending on which way
you want to go in that compromise. I recommend tire pressures
of ~44 psi in front, and ~46psi in the rear for the AS03s.
Lastly, pay Tirerack the $10 to heat-cycle the tires for you.
Joe

 

Thanks Joe,
I use Tire Rack and the heat cycling. Will I need campber plates to get to those numbers?

 

Yes, I think so, and as I think about it, those tires are bigger
than the ones I was thinking of, so you might drop 2-4 psi
from the figures I quoted.
Are you really running P245/40ZR-18s in *AS03*?
As far as I know, they only come in RS03, which would
be bad, because your first run would always be wasted
in terminal plough until the front tire warmed up.
Joe

 

I'm running 245 35 ZR 18's up front. This is my second set and all grins so far.
I built "tire ovens" for my car as tire warmers are not allowed in SCCA.
Lowes carries a product called Reflectix which is two thin pieces of Aluminum foil sandwiching bubble wrap. I made tire covers (like on the back of an RV) with cutouts where the tire meets the road. In the front I cut out a flap which lines up with the radiator outlets and I open the flap and it attaches to the outside of the front fenders via covered magnets.
Prior to gridding my car, I go for a short drive and make several hard stops (warming up the rotors). I also attempt to get into the boost as much as possible (warming up the turbos). Upon returning to the grid I put on my tire ovens and bake the tires for Approx. 15 minutes with the motor running and the A/C on (blows air through the radiators).
Using this technique, I can usually achieve 25 - 30 degrees above ambient Temp. This along with the "A" compound allows me to not waste my first run. I was taught this by a local veteran autocrosser and had the idea reinforced when I attended the CenDiv championships and met Danny Popp (current national champion and great guy). I just adapted the technique to take advantage of the Porsche radiator vents and turbo locations

 

Interesting! Yes, the *235s* com in AS03. Are you at all
concerned about the difference in diameters of the front and
rear? I guess if you're trailering the car, it doesn't get enough
road time with this setup to do too much heating of the
viscous clutch...
Joe

 

I raised this concern with my dealer (who is very aggressive in helping customers who actually use their cars ie: race). He has several customers running this setup without difficulties. I have a friend who runs a 993 TT with the same setup and no problems. It really improves/removes the middle of the corner low speed push I experienced with stock tires.

 

bbeasley-

Did you call Hoosier as well to get some feed back on tire pressures?


also,


Glad you found the forum. There is a ton of info to be soaked up.


I'm typing this at the offices of GIAC in SoCal. We have an Audi S4 shootout sponsored by European Car on Monday. If anyone is around, stop on by. Should be interesting...

Talk to you soon!

 

Good luck in the shootout Mike. Some of my S4 buddies user your stuff and say it kicks ****.

 

Hoosier gave me the same pressures with slightly more conservative camber settings. The regions I race in seem to favor sweeping turns and as such I think I can trade some braking bite for turn bite and go with the more aggressive camber settings.