Greg Lab

I am planning to run my GT3 in an autocross in a couple weeks. I have read the the material on the forum about tips for AX, and that is all good, but was wondering if you guys had any specific tips for the GT3. Tire pressure suggestions seem to be about 32/36 hot (for a 997)... What do you think for a GT3? I guess I will run around in 2nd gear as it is all 40-60 mph...

I want to explore the limits of the car in a safe place. I can tell already, it is much more edgy than my turbo with all the chassis handling features. I used to race SCCA FM's, and the car seems more like that (with much more power) than it does a typical HP street car. I mean, like the FM, weight transfer must be critical. Feels like it could spin pretty easily if incorrectly driven. I mean I enjoy it, it feels light and crisp, but I can tell it will bite you too... Anyway, just want to learn the car a little more in a safe place.

CosmosMpower

If you raced FM you're probably fairly experienced at autocross. I only ran my GT3 a few times (used to run a SS Elise a lot) but the setup should be a bit looser for autocross than track, really use the slow in fast out method and abuse the low speed acceleration of the 911 coming out of tight corners. I ran my PASM on sport mode for autocross, in street mode it was too sloppy and slow to transition in slaloms. On the big track I use the PASM in street mode to keep the rear more tame on high speed corners. Depending on the course setup in your region I'd guess you could easily run the entire course in 2nd.

robbieracer

I started doing AX this year and have done 6 (4 with a 996 and the last 2 with GT3). There is another guy with a 997.2 GT3 and he keeps his rears at 35 hot (don't recall front psi). Sept. I started at 29/33 cold on a hot 95 degree day and lowered my rears a hair after lunch. Last month was 75 and cloudy, I started at 30/33 cold and didn't let any air out, car felt great. I was 5th overall but the fastest with non R tires; I'm running MPSC2. I never checked my temps/psi, but looked at side wall rollover and it was perfect. I have the DSC w/392 front springs running at full stiff/sport mode. Sway bars are middle front/rear. Car worked great! Previous month I was on stock front springs w/DSC and front end rolled over too much, felt too soft for me. Was used to Ohlins R&T on my 996. As mentioned above, it's best to go slow in fast out. I tend to go in a little hot and get out of shape, my later runs are fastest once I get a feel for the car.

cgfen

if you are doing AX with San Diego region, PM me, I'll hook you up with a good instructor.

Greg Lab

No I am in Houston, doing it with Lone Star Region PCA at the HPD test track, looks pretty cool, more of a track, so fewer cones.
Nice video, good catch at the end! Good photo and information too, thanks. I am looking forward to it now, psyches me up!

Do you late apex the turns for fast out? Maybe there is not enough room... Or do you treat them more like sweeper? I was thinking of showing up with 1/4 tank of fuel. Do you guys launch the car at the start? Maybe 3000 rpm?

Drew_K

I should be at that event, likely instructing. I'll be in a white 997.1 GT3. Look for me and I'll be happy to help as much as I can, and you can catch a ride with me as well.

For tire pressures, I run 36 all the way around. I like to add a little up front for additional grip and to help roll over. The GT3's have huge rear grip, so I've found it's really more about managing the front. And you do want to apex slightly later than other cars, but it's a subtle difference. The biggest things will be positioning the car correctly and staying close to the cones.

That site, HPA, has very grippy concrete, which is fun, but there are a few areas where you have to respect the course. An instructor at the last BMW Club event there drove a student's car off track and damaged it. Talk to me or another instructor at the event and they can give you the low down.

Greg Lab

Great, thank you Drew. I will seek you out Sat morning. Check your PM please...

e3113v

Please correct me if I am wrong but I thought Michelin MPSC2 tires were R comp?

robbieracer

MPSC2 have a 180 tread wear rating, so I consider them soft street tires. The other guys are running Hoosier A8 with a tread wear of 40, so when I say R rating, I'm referring to the super soft sticker tires that you wouldn't want to drive on the street. I'm not sure what the true definition of a R tire is.

Greg Lab

How many miles do you typically get out of MPSC2 on the street? I have a turbo and it eats P zeros for lunch, maybe only get a few thousand miles on street. But then after racing, I will never complain about my tire bill on street...