Tyre Pressures for Track Day
Discussion
Yep. I have a Boxster S with 18" GT3 wheels that I track regularly.
Depends on the track and the day as to what is necessary. I set my tyres to Porsche recommended road pressures when cold the day before. If necessary and I am either getting excessive tyre wear on the shoulders of the tyre OR its getting skittish under hard braking I might consider letting some air out. I carry an electric pump for putting this back afterwards for the journey home.
Most days I don't need to let any air out. If its cold or rainy its unlikely you'll work up enough heat in the tyres to raise their pressure enough to be problematic. On a hot summer day in the dry on a track with fast corners...might well need to do something.
Depends on the track and the day as to what is necessary. I set my tyres to Porsche recommended road pressures when cold the day before. If necessary and I am either getting excessive tyre wear on the shoulders of the tyre OR its getting skittish under hard braking I might consider letting some air out. I carry an electric pump for putting this back afterwards for the journey home.
Most days I don't need to let any air out. If its cold or rainy its unlikely you'll work up enough heat in the tyres to raise their pressure enough to be problematic. On a hot summer day in the dry on a track with fast corners...might well need to do something.
I'm very surprised you don't need to reduce the pressures on track?
From cold to track pressures on almost all tyres and wheels I have used I tend to have to let between 8-15psi out as the tyres get hot?
A lot will depend on the tyres you are running on the track as the sidewalls will have an impact on the pressures you need.
What are you running?
From cold to track pressures on almost all tyres and wheels I have used I tend to have to let between 8-15psi out as the tyres get hot?
A lot will depend on the tyres you are running on the track as the sidewalls will have an impact on the pressures you need.
What are you running?
Don said:
Depends on the track and the day as to what is necessary. I set my tyres to Porsche recommended road pressures when cold the day before. If necessary and I am either getting excessive tyre wear on the shoulders of the tyre OR its getting skittish under hard braking I might consider letting some air out. I carry an electric pump for putting this back afterwards for the journey home.
Most days I don't need to let any air out. If its cold or rainy its unlikely you'll work up enough heat in the tyres to raise their pressure enough to be problematic. On a hot summer day in the dry on a track with fast corners...might well need to do something.
Most days I don't need to let any air out. If its cold or rainy its unlikely you'll work up enough heat in the tyres to raise their pressure enough to be problematic. On a hot summer day in the dry on a track with fast corners...might well need to do something.
You must be driving very sedately in the car (and I mean no insult), on a trackday you should find the tyres are increasing their pressures quite significantly. The trick is to measure them as soon as you come off the circuit ie. when the tyres are still hot. Ideally come straight off a flying lap into the pits mid session and adjust them, (you should really allow the brakes to cool down on a cool down lap at the end of the session so you will find the pressures drop a tad if you measure them after the cool down lap at the end of the session).
In terms of where to set them start off aiming for your normal pressures hot. If you`re running "track" tyres then 30psi or a couple of bar is usually a good starting point. If you really want to get technical then you need a tyre pyrometer (measures tyre temperture). Straight off the circuit measure the outside, middle and inside of the tyre. You are looking for as even a spread as possible. The geometry (mainly camber) will dictate the spread from inside to outside, the tyre pressure will control the middle temp (high temp too much pressure, low temp too litle). For occasional trackdays though just spend £40 on a decent pressure guage and keep checking them until they stabilise (obviously when you start a new session after a break the pressures will be low and you`ll have to work heat into the tyres over a couple of laps to get the pressure back.
Hope that helps
Henry
Edited by henry-f on Friday 8th December 01:29
henry-f said:
You must be driving very sedately in the car (and I mean no insult)
I am quite sure in comparison to your good self I am tootling around like my old granny!
It could well be I could benefit from letting out more air than I do both in tyre wear and grip. So far I have not really found the need to let much out - just if I have noticed some unexpected oversteer or instability under braking. Perhaps I should be worrying about this more. Or perhaps I am just Captain Slow!
Thanks for your excellent advice as always, Henry.Gassing Station | Porsche General | Top of Page | What's New | My Stuff