simp2601

I have a 991.2 C2S which I am planning to take on track. I have been doing track days for years and raced in the past but am unable to find the Porsche recommended tyre pressures for track driving in the handbook. When I had a 981 Cayman S, the handbook advised that the same pressures should be used for the track as for normal driving on the road. Of course the tyres would get much hotter on the track and therefore be running at higher pressures anyway.

I would be most grateful, therefore, if those of you who have taken your 991.2 round a track could tell me what pressures they use. The road tyre pressures mentioned in the handbook are:-

Part Load - Front 31 psi Rear 37 psi

Full Load - Front 34 psi Rear 44 psi

I am inclined to assume that the Full Load pressures are the ones to use for track work but would welcome any thoughts that my fellow members might have on this subject.

Doug H

Pick up a pyrometer and check temps across tires after each run and adjust accordingly. Depends on ambient temperature, track temperature, skill level and etc.

991carreradriver

Doug H. is spot on with his recommendation.

In the meantime, if you are running P-Zero's at the full load recommended pressures it will melt your tire on the track (ask me how I know). The rears will exceed 50 PSI during hotter weather ( Mid 70's and above) at those recommended pressures.

I would start out at 30 front 33 rear and use your TPMS as you drive the first few laps. Those tires work pretty well hot at 36F 39R hot.

simp2601

Many thanks for the replies. I just wanted a starting point for pressures on track so I could take it from there. I know the P Zeros get hot as I had them on my 981 Cayman S and the tread would get sticky like a slick - but they still performed well and gave lots of grip. I know that some 991.2 owners in the US are using their cars on track and it would be helpful to know what their starting pressures are from cold. 991.2 cars are very rare in the UK at the moment, in fact I have yet to meet another 991.2 owner let alone one who tracks his car.

CarManDSL

I'm running Sport Cup 2's on 2012 991S with SPASM.

I start first laps cold at about 24psi F and 26 R. After 20 min session on a cooler day, say 70F, I'll end session at 31/34 ish. I'll adjust accordingly throughout the day and try to maintain a 31/34 hot.

Around town, cold is set at 29/32 in Comfort Mode.

simp2601

Thanks for that carManDSL. Every bit of knowledge on the tyre pressure front is helpful.

Jabs1542

Do you get TPMS alerts in the MFD? I seem to be fighting the TPMS every time I go to the track (yesterday as an example). Even in Comfort Mode my TPMS doesn't like pressures as low as 24, 29, or even 31 - sometimes I get yellow alerts at 33.

Once I complete a warmup lap the pressures go up and while the previous alert doesn't go away I don't get additional alerts. Anyone else have this problem? Anyway around it?

BradB

Mine does the same. A way which I help avoid it is I start off just above what I estimate will set off the TPMS then as the temps rise on the track I come in and let air out gradually. I may have to let air out several times, but it beats looking at that yellow warning all day long. And don't get the tires totally heated up and then let gobs of air out. This rapid change in pressure will also set off the TPMS. It's a pain, but I come in once or twice in the middle of my first session, usually. Or make your warm up session a short one. Then the rest of the day is fine.

Jabs1542

Thanks, reducing in increments works.

However, I've got a pretty good idea where I want the pressures when I first get to the track (at least a starting point) and figured out a cool trick.

When you get the yellow alert, then look at your TPMS screen in the MFD and everything looks correct, just go into settings and toggle Comfort Mode off and then back on - yellow alert clears itself and the nagging ends

BradB

Nice trick! I'm going to try that!