Tyre Pressure on Track

R60BBA · Post by **R60BBA** » Tue Mar 20, 2018 10:10 pm

What tyre pressure is best for track use?

I drive a Z4C with 225/40/18 on the fronts and 255/35/18 on the rears.

Tyres are Michelin Pilot Sport 4.

For street driving I run 33psi on the fronts and 36psi on the rears.

The car is booked in for its first track evening at Snetterton on 26 April and so I welcome your views.

jpvd · Post by **jpvd** » Wed Mar 21, 2018 10:54 am

i'm doing a track day at cadwell this friday...(can't wait!!)...

I was told to deflate the tyres by around 3psi....then after a run check them and deflate a little more if the pressure it too high....

others may advise differently though!?

Scooba_Steve · Post by **Scooba_Steve** » Wed Mar 21, 2018 12:07 pm

I run 33F and 35R on Goodyear Eagle F1 on the road and this gives me even wear. On track I use +3 psi once they warm up. I've not tested temps or adjusted much after that but it's a good starting point.

ph001 · Post by **ph001** » Wed Mar 21, 2018 12:32 pm

I would typically reduce the pressures from the recommended road pressures by 3-5psi and trim them down again to the desired pressure after a session when they're hot.

What you will almost inevitably find is that you get a big imbalance between left and right side (unless the track has balanced G loading between left and right corners) so it is important to measure them after a few hot laps and equalise all the pressures left to right.

R60BBA · Post by **R60BBA** » Wed Mar 21, 2018 1:13 pm

Scooba_Steve wrote: ↑Wed Mar 21, 2018 12:07 pm I run 33F and 35R on Goodyear Eagle F1 on the road and this gives me even wear. On track I use +3 psi once they warm up. I've not tested temps or adjusted much after that but it's a good starting point.

Just to clarify.

Do you increase your tyre pressures by 3psi before you jump on track? Or are you saying that your tyres naturally go up on track by 3psi due to heat etc?

I was always of the opinion that for track driving one should lower the pressure of their normal pressure by a few psi?

R60BBA · Post by **R60BBA** » Wed Mar 21, 2018 1:17 pm

ph001 wrote: ↑Wed Mar 21, 2018 12:32 pm I would typically reduce the pressures from the recommended road pressures by 3-5psi and trim them down again to the desired pressure after a session when they're hot.

What you will almost inevitably find is that you get a big imbalance between left and right side (unless the track has balanced G loading between left and right corners) so it is important to measure them after a few hot laps and equalise all the pressures left to right.

Thanks. I’m a bit of a track novice despite driving the Nordschleife in 2015.

How many laps would it take at Snetterton for the tyres to warm up? The 300 Circuit is 3 miles I believe.

hopz121 · Post by **hopz121** » Wed Mar 21, 2018 1:17 pm

I would aim around 28-32 PSI hot and see how you go, its all down to personal preference really and tyres fitted.

Drop your pressures on arrival by 5 Psi ish and keep an eye on them, try to maintain the same temp throughout the day

Yorkie Z · Post by **Yorkie Z** » Wed Mar 21, 2018 2:21 pm

hopz121 wrote: ↑Wed Mar 21, 2018 1:17 pm I would aim around 28-32 PSI hot and see how you go, its all down to personal preference really and tyres fitted.

Drop your pressures on arrival by 5 Psi ish and keep an eye on them, try to maintain the same temp throughout the day

Exactly this

Scooba_Steve · Post by **Scooba_Steve** » Wed Mar 21, 2018 2:43 pm

The pressures will go up as the tyres heat up, as you're working them harder than normal you'll want to let the pressures rise a little over normal hence my aim of +3 psi once they have warmed. You can lower before you go on or let them warm and check. As my first few sessions are shorter i tend to let them warm and just let out on coming back in. Also good advice about keeping them even.

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