track day tyre pressures
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[FONT=Trebuchet MS"]No easy answer because so many factors need to be considered. Speak to a proper tyre specialist or even Michelin themselves (try Darren Spooner at Michelin Technical 0845 366 1535) to obtain a starting point though. Tyres have an optimum operating temperature for the tread to work efficiently. This is affected by the air temperature, track temp, abrasiveness of the track, dry/wet weather, your cars setup and your driving style.
Maybe start by using road settings but coming back into the pits after only three or four laps. Check the pressures and the tyres working the hardest will obviously be the hotest and as a result the tyre pressures will increase at different rates fpr all four tyres. If they are the same as when you started you are ready for Driving Miss Daisy Part 2.
Talk to people at the track day. It's an easy conversation starter and normally you will find everyone is very friendly and willing to help someone who has just started the learning curve.
One final tip. Don't try to break any records. Build up the speed gradually and enjoy the car. Impatience will end in gravel rash!![[FONT=verdana,geneva"]](/forum/styles/default/pcgb/space.gif ". [FONT=verdana,geneva\"]")
Maybe start by using road settings but coming back into the pits after only three or four laps. Check the pressures and the tyres working the hardest will obviously be the hotest and as a result the tyre pressures will increase at different rates fpr all four tyres. If they are the same as when you started you are ready for Driving Miss Daisy Part 2.
Talk to people at the track day. It's an easy conversation starter and normally you will find everyone is very friendly and willing to help someone who has just started the learning curve.
One final tip. Don't try to break any records. Build up the speed gradually and enjoy the car. Impatience will end in gravel rash!
By way of a starter , as Garry suggests experimentation is neccessary , track surface [weather and abrasiveness] affect the temp but u want to be at 30 hot all round ,probably means starting cold at 24 fronts and 23 rears by all means keep coming in and checking but more laps without stopping hotter they ll get and dont hang around when u ve pulled over get a reading as soon as u can safely...............'outside set ', lhs will need to be a half pound or a pound lower as they heat up that bit more ..............last tip its always easier to let it out than put air in!!
Normal road driving will increase ur temp therefore pressure 2/4 pounds so the above allows for gentle track day ,on a warm day rears especially can go up 8/9 ilbs
Normal road driving will increase ur temp therefore pressure 2/4 pounds so the above allows for gentle track day ,on a warm day rears especially can go up 8/9 ilbs
Guest
New member
I would echo Vic's comments but after a few years of track days in a 3.2 I can be a bit more specific. If you have R-compounds tryes on wide rims then aiming for 30psi hot is about right. Silverline advised me to aim for about 30-31 psi hot when I first started using R tyres. If however you are using road tyres on the narrow 6/7 inch std rims, I would probably aim for a slightly higher pressure like 34-35 psi hot. which means starting at about 27 psi rear and 29 psi front. Because the standard size tyres have a fairly tall sidewall and are not stretched on the rim, I think you will want a little extra pressure to stiffen things up - I concede that this may give you a touch less ultimate grip but I think the trade-off is about right for a std unmodified 3.2. You have to remember that Vic is probably more used to his 993RS and 993GT2 with big wide rims and much lower profile tyres.
One word of caution, if you start with cold pressures in the mid or low 20s, you will have *much* less grip on your out lap. You really need to put in a warm up lap to get the pressures up to their warm levels. If you ignore this, a big unexpected slide is usually the result. Ask me how I know...
Richard
One word of caution, if you start with cold pressures in the mid or low 20s, you will have *much* less grip on your out lap. You really need to put in a warm up lap to get the pressures up to their warm levels. If you ignore this, a big unexpected slide is usually the result. Ask me how I know...
Richard
"on the 3.0RS"
Wondered when u'd drop that in.... [
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S'funny how the tyre pressures seem similar on 911's across the board. Used to run my 964 C4(PO) at 34-36psi hot on track days. The Cup Car I ran P0C's at 32hot, the P0 slicks I now run seem happy at about 30psi hot, after starting at 23-25psi cold........although a mere 2psi increase during a session can make the rear a bit loose, take that as you wish!!
Mel
Wondered when u'd drop that in.... [
]S'funny how the tyre pressures seem similar on 911's across the board. Used to run my 964 C4(PO) at 34-36psi hot on track days. The Cup Car I ran P0C's at 32hot, the P0 slicks I now run seem happy at about 30psi hot, after starting at 23-25psi cold........although a mere 2psi increase during a session can make the rear a bit loose, take that as you wish!!
Mel
Guest
New member
Mark,
Don't get too worried about it. It sounds like you are fairly new to this, so start with pressures a little lower than you normally use and keep an eye on them after each session. You will almost certainly be letting air out after each of the first 3 or so sessions. As you learn and progress you will get faster and you will generate more heat and need to bleed out more air. So long as your hot pressures are fairly even and in the 30-36psi range nothing untoward will happen (as a result of pressures at least). If you find you have hot pressures in the 40s then you are way too hot and need to let air out. Otherwise, take it easy, relax as much as possible and have a good time. Its a track day, not racing and the last split seconds do not count.
Given that you have a lot of rear tyre (compared with the fronts) you may even decide to play with the pressures to alter the handling balance in the second half of the day. If you take a couple of pounds out of the fronts you will increase front grip a little and vice versa for the rears. For this type of reason, there is no right answer for tyre pressures. Experiment, have fun and soon you will be giving advice like the rest of the battle scarred veterans round here.
Richard
Don't get too worried about it. It sounds like you are fairly new to this, so start with pressures a little lower than you normally use and keep an eye on them after each session. You will almost certainly be letting air out after each of the first 3 or so sessions. As you learn and progress you will get faster and you will generate more heat and need to bleed out more air. So long as your hot pressures are fairly even and in the 30-36psi range nothing untoward will happen (as a result of pressures at least). If you find you have hot pressures in the 40s then you are way too hot and need to let air out. Otherwise, take it easy, relax as much as possible and have a good time. Its a track day, not racing and the last split seconds do not count.
Given that you have a lot of rear tyre (compared with the fronts) you may even decide to play with the pressures to alter the handling balance in the second half of the day. If you take a couple of pounds out of the fronts you will increase front grip a little and vice versa for the rears. For this type of reason, there is no right answer for tyre pressures. Experiment, have fun and soon you will be giving advice like the rest of the battle scarred veterans round here.
Richard
Just old Richard ,try to cover the scars ! Mark if in a couple of weeks, as u put it, thats a PCGB day?,maybe even Silverstone i wud be only too pleased to help if u feel u need it ,even at my age i can let air out of tyres and Richard is right just enjoy it and basically suck it and see
Have fun
Have fun
[FONT=Trebuchet MS"]Although MICHELIN say 36 psi all round we run the GT3 shod with Pilot Sport Cup tyres on track between 28 and 30psi HOT. This equates to around 2 bar. The Cup Cars run these pressures. However if you are driving Miss Daisy (or is that Mr. Cohen) it is probably prudent to start at 36 psi hot and see how it goes.
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