Airfield day tyre pressures

[doddze]

I have an airfield training day coming up in the not so distance future and was wondering what people would suggest upping the tyre pressures to in order to protect the tyre walls. I am running 60 profile.

I was thinking of 34psi.......

[bugsy]

According to Steve Heath, 2 to 3 more PSI
than usual

[apguy]

Tyre pressure questions tend to provoke 3 answer, all with their relative merits:

Reduce by 2/3 psi
The rational being that increased tyre block movement caused by hard acceleration and cornering will heat the tyre up, causing the moisture in the tyre to expand and naturally RAISE the tyre pressure back to std pressure.

Increase by 2/3 psi
Therefore increasing rigidity of the sidewall and carcass, in order to prevent tyre movement and therfore reduce the amount of heat build up that affects the tyre pressure.

Standard Pressure
You drive the car everyday on these pressures, you know how it handles, its predictable. Why change to an unknown quantity and have to relearn the handling.

I race saloons (and have done for 7 years) with a Nat A race licence. For race purposes I actually lower the tyre pressure, to take into account heat build up. But I have also used Nitrogen instead of air in my tyres which has no moisture. Tyre pressure stability is greatly improved.
My view? Leave them as standard.

[doddze]

Interesting.......... the people running the event suggested an extra 10psi so the tyre walls wouldn't be damaged as they felt the S Series was prone to a bit of tyre wall "rolling" when cornering hard.....

[Roy C]

apguy said:

My view? Leave them as standard.

Agreed.

I used to add 2psi, but I've found it makes no difference for a track day.

[Roy C]

doddze said:

Interesting.......... the people running the event suggested an extra 10psi so the tyre walls wouldn't be damaged as they felt the S Series was prone to a bit of tyre wall "rolling" when cornering hard.....

10psi!!

Not safe.

Maybe they mean 10%?

>> Edited by Roy C on Thursday 13th January 11:09

[apguy]

10psi increase is bordering on the insane.

Tyrewall deflection is an inherent part of your vehicle suspension and can play an important part in your handling characteristics. I wouldn't go tinkering with settings outside the tyre/vehicle manufacturers specifications.

[doddze]

The y definately said 10 psi not 10 % ( they suggested a total of 41psi for Skyline!!!!

Think I will just top them off at about 25psi and be done with that!!

[GreenV8S]

Keep the pressures standard, and monitor the tyre temperatures (as well as all the other usual things - pad wear, oil level, water level, tyre pressure) between runs. Aim to keep the tyres below about 60 degrees. The tyres will naturally pick up an extra 3-4 psi as they heat up, and that's fine. You can let air out to bring them back down to your normal pressure if you're feeling keen, as long as you remember to pump them back again after the event. Personally I don't bother unless I'm after maximum grip, which at normal track days is not something I bother about.