Tyre pressures

[GC9911]

Guys & Amanda,

I am going to Targa Tas in April driving with PCA on the closed road stages & Symonds Plains on the first day. my question is what tyre pressure do you recomend ? For the track & the road?

I have a 991 carrera S manual, tyres are Pirrelli P Zero 245/35 ZR 20 at the front, 295/30 ZR 20 at the rear. Track speed can be up around 200 plus, road speeds are usually under 190, road stages vary between roughly 6klms & 50 klms. The shorter stages are usually quite twisty & the longer stages are a mix of free flowing straights with some twistys in the middle.

All advice great fully received.

PS. I chewed up a set of Pirrelli P Zero tyres last time in a 2010 911 C4, they had 10,000klms on them & were ok when I set off & were "F word" after 4,000klms of Targa trip. Am I being unrealistic about tyre life?

[Harvs11]

I've been told to add 5 psi over recommended pressures in a road tyre for any spirited driving.

Maybe some R-specs might be better and save your road tyres.

[GC9911]

Thanks Harvs, I assume we are talking cold pressures as a base in all discussions? I thought about R specs but I'm a bit paranoid about driving Sydney - Melbourne - Sydney If we get wet weather.

[wasserkuhl]

Ambient temperature is also an important consideration as the tires heat up the pressure(s) will also rise.

 

I would strongly recommend getting a professional alignment and geometry set up done prior to doing this event.

 

The cost of this will be about 1/2 the cost of one new tire(probably less!) and will save the tires for you.

 

Its a new 991 however you will be surprised to learn how far out the alignments are on new cars, even very expensive cars ....

 

I would also strongly recommend R spec rubber. They aren't as bad as you may think in the wet..........you just need to adjust your driving style to accomodate them should you experience wet weather.

 

My Toyo R888's are very good in the wet, if they are up to temperature.

 

I'd only invest in R rubber if you are planning on doing more events and track days.

 

For your 991 I would suggest Michelin pilot sport cups as they are a more intermediate pattern and have good all weather performance.

 

They aint cheap though.

 

Neither are coffins

[sydr]

Ambient temperature is also an important consideration as the tires heat up the pressure(s) will also rise.

 

I would strongly recommend getting a professional alignment and geometry set up done prior to doing this event.

 

The cost of this will be about 1/2 the cost of one new tire(probably less!) and will save the tires for you.

 

Its a new 991 however you will be surprised to learn how far out the alignments are on new cars, even very expensive cars ....

 

I would also strongly recommend R spec rubber. They aren't as bad as you may think in the wet..........you just need to adjust your driving style to accomodate them should you experience wet weather.

 

My Toyo R888's are very good in the wet, if they are up to temperature.

 

I'd only invest in R rubber if you are planning on doing more events and track days.

 

For your 991 I would suggest Michelin pilot sport cups as they are a more intermediate pattern and have good all weather performance.

 

They aint cheap though.

 

Neither are coffins

 

I heartily endorse what W has suggested. 

 

R-spec's vary as to their rain weather capability, so ask around.  And then be mindful if it is wet, which is zackerly what you'd do on standard rubber anyway, even more so on some Targa stages that have slippery surfaces that don't see much sun.

 

I'm well satsified with Kumho's; they have surprised me at how good they are in the wet - but I'm careful to watch out for aquaplaning because they won't move as much water away from the contact point as more 'universal' tyres.

 

AutoHaus Hamilton (Just James on this forum) havs had very good results with the new A050 on the competition cars that they prepare but I've not driven on them and can't offer a personal opinion.

 

Alignments can make a massive difference, and they vary according to use.  A track set up will probably 'tramline' and won't be suggested by someone who does not know how to set your car up for spirited driving.  Tramlining aside, a track set up will be more predictable, will turn in better and hang on longer, so I'd suggest you find out who can do it for you.  It is no biggie to reverse it after the event if you prefer a more vanilla set up for every day use.

[GC9911]

Thanks for your informative replies, &yes I do rate Michelin pilot sports highly from past experience.

[Stardust]

Hi W,

 

Just reviving an old thread but what pressures (hot) do you have in your 888's for track days?

 

I'm currently at 30psi all round, but that damn PP board keeps talking circa 40psi!

 

Syd, I hear the A050s are very good, but they don't run them in my sizes until you go 17 inch rims.

 

My setup is:

 

225/45/R16 on 16x7 front

245/45/R16 on 16x8 rear

1144kg wet

[MaxzmusSC]

I've often run them around 30psi hot after a few warm up laps. This is assuming your on the GG Compound.

[Stardust]

Yep, GG compound.

[Cal]

I've raced on R888's for years. 30psi hot is the target. Over 33 and they start to melt and slide. Anyone suggesting 40 has no idea what they are talking about. 

[MaxzmusSC]

Agreed.

[Kelly]

For 888's 32F 35R was the sweet spot for my 996 on  race suspension running in UK summer conditions on smooth dry tracks & damping set accordingly.

 

As my avatar shows, at apex on a sharp bend  my suspension didn't exactly exhibit a significant amount of body roll.

[9fan]

GC,

Will be able to tell you in Dec when we finish our RTT to Tazzie.

Intend to run the 888s at Symmonds Plains and around the Apple Isle.

My 968CS is a bit different in weight and balance but I generally do road at 32psi and track at 32R/34F Hot.

run 245/40/18 and 295/30/18.

Cheers.