devenh

I am at a PCA track event at Thunderhill and out of curiosity I asked the track marshal if Cayennes were allowed on course. Never having seen one on course, I was surprised that the answer was 'Yes.' This was the same answer I got when I asked if I could take my Cayenne out during the last session on Sunday (typically pretty sparsely attended).

I don't intend to go out and hammer the car, but I would like to get my tire pressures in the right ball park. Since I won't be able to fine tune the pressures over multiple sessions, I'm really interested in cold pressures to start with. In any event, please be sure to specify whether the pressures you are recommending are cold or hot.

Car details: '14 Turbo S, 21" wheels, 295/35R21 P Zero tires, factory pressures are 39 front, 46 rear.

extanker

imho....stay at factory or 2 lbs over [so you do not roll off the rim] and always cold .

bweSteve

IMHO 2 lbs over will not do it.

I've been autocrossing my '12 CTT, same 295/35R21 for a couple years now,... and I start out cold at 46 on all 4, then after 2nd run it has ramped up to 49 & I back it down to 48 for the rest of the runs.

I guess it could be different for a full course DE,... but autoX is pretty tough on tires with all the constant turning. Anything less & I can feel the roll, and see a lot of scrub reaching onto the sidewalls.

The first few times I started autocrossing (couple yrs ago), I tried a couple pounds lower on the fronts (verses rears), since that's what Porsche recommends for normal driving,... but I didn't like the push I felt from the front end, so I started running the same on all 4.

I also have PDCC & PTV.

Have fun!
=Steve

Spyerx

I need to take my diesel out one of these days. Lol

I rated the car on the zone 8 car class list and it's rated about the same as my stock 89 carrera.

devenh

So I did 5 laps on Thunderhill (3 mile cyclone). I set the cold pressures to 46 lbs all around. After a couple of laps, TPMS showed 52 lbs, which is in line with the the cold to hot pressure increase I see on a sports car. Although I was not pushing the car, I thought 52 lbs might be a little too much and returned to the pits. My guess is that 42 lbs cold would have been a better starting point. My best lap time was 2:31.

Not surprising, you're very cognizant of the vehicle's weight and height (I was in the low height setting, sport everything) on the track. It's acceleration does bring on a smile.

If you ever have an opportunity, I would highly recommend taking a Cayenne on the track just to see what she'll do.

bweSteve

wow, a 6lb increase. no doubt a big difference in speeds on a track, verses the cones of autoX (of which I usually only see a 3-4 lb increase).

Thanks for posting your results. I'd love to bring it out at Summit Point WV close to me,... but I fear I would tax my brakes too much. If I had PCCB I would be out there!!