ltcjmramos

Hi

Anyone out there running a 997GTS in autocross? I'm looking to pick it up again after many years away. Don't know how serious I'll get about it, but want to prep as best I can. For now, I'll remain stock (street tires/wheels, alignment).

I autocrossed 1st and 3d gen RX-7s with NCSCC and SCCA here in No CA from '86 to '92 before moving to the track with the 3d gen in '92. I ran track with that car until '99.

I then took an hiatus until '05 when I did DEs with PCA-GGR and other organizations with my 993TT and 996GT3 for a couple of years. Due to a motorcycle accident in '07 I did no driving for a couple of years rehabbing from surgeries. Since recovery, haven't done anything other than canyon-carving. I'd like to get back into autox. I now drive a '12 GTS.

Advice/comments?

Thanks

kpl

You don't need to do any prep to your car Joe. Just bring a tire gauge and pump in case you want to change pressures. You should have come out Sunday for GGR's event at Alameda. GGLC (Lotus) is running their last event for the year on Sat at Marina, but I think it is waitlisted. GGR's last event is Nov 18.

ltcjmramos

I'm signing up for the Nov 18 event.

I don't have my usual equipment any longer, e.g., air tank. What I'm looking for right now is what air pressure folks have found good for the 997GTS (and/or 997C2S).

kpl

I just have a small air pump to plug into the cig power. I'd start with the same pressures you run on the street. You'll likely end up bleeding air off as you get faster to try to get heat in them.

Anker

Chalk the wheels. The optimal tire pressure varies from tire to tire, so there's no magical number. Right now my Sumitomo XTR III rears need to be brought down to approximately 32 PSI for good performance. The rear tire pressures in the manual are designed to cause understeer and will also give you too little grip with the tires I have run with.

Let me know if you don't know how to chalk the wheels and read what they tell you.

An even better method is to measure the temperature of the tire immediately after a run. It should be as close to even across the tire as possible for optimal performance. Too hot in the middle is too high pressure, too high at the edges is too little pressure.

sjfehr

What kind of tires are you running, Joe? Sidewall stiffness matters. I've found Porsche's specced cold pressures for my 987.2S are pretty close once the tires warm up and gain a few psi, but they roll over if I don't put air in first. And this is with RE-71R which are really stiff. Better to err on the side of caution and put in a little extra; easier to bleed out than put more in, and less risk of sidewall damage.

ltcjmramos

Bridgestone Potenza S-04.

I know it's a bit of trial and error, day to day, run to run, but looking for a starting point.