Track Day Tyre Pressures

[hanhams81]

Hi Folks,
Now the track day season approaches a novice seeks advice about appropriate tyre pressures. My initial part day experience last year was conducted at standard road use recommendation for my 993 C2. At one point the rears did feel a tad jelly like but after a cool down normality returned. The condition did not return. My next venture on track will be a full day PCGB event. The 993 wears Continental tyres which have given good road service to date. So regulars, what pressures do you recommend?
Hanhams81

 

[oliverjamesthomas]

Go for 32 front and 34 rear, cold. Go out for a session and when you come back in, check them again and reduce them to the cold pressure you started with.

You just need to remember to allow a couple of laps for the tyres to come back to temperature when you next go out and also to put some air in before you leave the circuit.

Regards

 

[kennyboy]

Do you know if I could do the same in the tt Oliver?

 

[oliverjamesthomas]

Hi Kenny

Hope everythings good with you. I can't comment on exact pressures for the TT, because my only experience is with 17" rims and the pressures for 17's and 18's are worlds apart. In principle though, if you go out on normal cold settings and start to drop them back when the tyres are hot, you should overcome any handling or tyre life issues.

All the best

Oliver

 

[kennyboy]

Hi Oliver, I'm good thanks.

Of course, I forgot you were on 17's. Thanks for the advice - I already run lower than Porsche's recommended pressures so I'll drop to my current setup...

Cheers

 

[Sundeep]

also depends on the tyres but can only comment on 17"

I ran 36-37.5" HOT front and rear, seems to work but in that range is subject to the factor of the weather conditions and tyre make

I know a few folk who have suggest 32-34 which can work on low speed/tight circuits but I never liked those settings and were awful at higher speeds

all part of the experimental process !

 

[Sundeep]

ORIGINAL: hanhams81

Hi Folks,
Now the track day season approaches a novice seeks advice about appropriate tyre pressures. My initial part day experience last year was conducted at standard road use recommendation for my 993 C2. At one point the rears did feel a tad jelly like but after a cool down normality returned. The condition did not return. My next venture on track will be a full day PCGB event. The 993 wears Continental tyres which have given good road service to date. So regulars, what pressures do you recommend?
Hanhams81

it is most likely the tyres were running too hot, which is a common problem if you start on the recommended cold temp, as OJT has said you actually need to start at a much lower cold temp or just keep taking out the excess air pressure as the day progresses (dont forget to put it back at the end of the day)

IMHO you need to experiement with as range of HOT running pressures in the range from 34 to 38 and see what you car suits best, assuming it is running on 17's

 

[pse_SC]

Sundeep, does your yellow sportscar handle "˜a tad jelly like' with those really low front pressures?[]

 

[oliverjamesthomas]

Now now, you've to remember that Sundeep likes to be out in front on a trackday - the fact he's bulldozing the circuit is a mere detail! [][]

 

[Sundeep]

that's the GT3's best side !

of course it's ideal for taking short cuts on track days as well, all those special Manthey upgrades [:-]

 

[RichardLW]

I found that 34F/38R hot on 18" wheels was about ideal for my driving style - a somewhat chuck it into the corner and see what happens approach which needs improving. Any higher than this and the rear grip disappeared very quickly - on P-Zero Rossos - and any lower induced an unpleasant wobbly sensation suggesting that the tyres were distorting too much. This was at Brands on a scorching hot day BTW and the amount of air I had to put back was amazing. After letting the car stand for an hour, still in the heat mind, I put 12lb into the back and about 10lb into the front.

 

[sailor]

Second that. I start at 28/32 cold on 18" rossos and usually get a 6psi rise all round on the average warm summer day.I learnt the hard way. On my first trackday I had the tyres at the book 36/44 cold and didn't touch them. Talk about skating rink !

JohnC
993turbo

 

[hanhams81]

Thanks folks. Very useful info. Being the novice I am I failed to mention my wheels are bog standard 17's, but you guessed that anyway.
By way of a prize I would like to award an A+ for relevance to pse_SC.

 

[hanhams81]

Thanks one and all. Subsequent to the advice I asked Continental Tyres for any advice they may care to offer. Their reply threw up an interesting point about mixing N rated tyres on our cars.



"Before I progress, I need to make you aware that there is a Porsche
directive regarding the use of tyres on their cars. These have both
warranty and insurance implications. As per Porsche's guidelines; the N
designation tyres have to match all four tyres on the vehicle. They can be
either 1, 2 or 3 but they do need to match.
As these may be your track wheels and not road wheels, it may not have any
bearing. I just wanted to inform you to err on the side of caution."

With regards to track use, it is largely dependant on the surface. I
personally drop ~ 2psi on the rear in order to obtain more grip. This
proves useful on most surfaces, especially tarmac. With the likes of
airfields such as Elvington and Bruntingthorpe, the sufaces tend to vary
within the track and can use quite a course cement. Running lower pressures
on these sorts of tracks will cause the tyre to deteriorate quicker then
expected under normal inflation.

Naturally, the balance of your car is unbeknown to me but as a general
rule, slightly lower pressures can yield positive results. Dropping any
further may result in inner liner wear over prolonged periods.
If it is possible (frequency of trackdays permitting), run some personal
tests using a set pressure for the day, then remove the tyre to check for
inner liner chafing. This will give you an indication as to how far you can
go without causing any internal damage, whilst retaining the best balance
for the car.

Hope this helps


Regards

Craig Sterry
Product Support Engineer

Continental Tyres Ltd
Technical Service Department
Haynes Way
Swift Valley Industrial Estate
Rugby
Warwickshire
CV21 1GZ

Tel: 01788 552937
Fax: 01788 552947
Mobile: 07702 537279




esting point I was unaware off. I copy for interest.

 

[LeoSayer]

I normally take the car out for a short session then come in and measure the pressure then. I found that I get the best handling if the hot pressure is around the standard cold pressure level.

 

[Yoda]

Thanks gents. Will be nice to get back on track in a 911 and will take it easy. Car is on road tyres (for the moment).

Regards

Feroz