tyre pressures at the track - what do you run?

[I-nearly-bought-a-batty]

Guys, how much pressure do you run on the track? - cold pressures please. From my experience, once the tyres heat up - they add about 5-6psi to the cold reading.

My tyres are 225/45/17 F and 245/49/17 rear. I usually run 35/36 on the road. I tried this on the track - no real probs but pressure got up to 42psi when resting . Tried 30 psi cold in order to get to around 35psi hot - not bad. Although I noticed the last time I was at the track, my tyres seemed to squeal more than previously noticed. Curious to see what you guys think...

 

[dcoghlan]

are you running normal street tires or semi slicks.

I have been through several different sets of semis and this is what I have used

Bridgestone RE55s - 26 cold
Dunlop D01J - 25 cold
Kuhmo Ecsta V700 - 26 cold

This was to bring my hot temps up to 31-32.

If you are driving on street tires, I am not sure what other people use as I have never been on the track with normal road tires.

 

[I-nearly-bought-a-batty]

yeah- I'm running regular street tyres - Goodyear Eagle F1's - GSD3's. They're not bad - quite sticky. Although I think I've found the limits of them on the track.

 

[Nicely]

35/36 on the road You must be bouncing all over the place...

Stock tyres are 32.

I run 235/40/18 front and 255/35/18 rear with 29/31 (warm). That's based on a formula someone on SXOC calculated. They are pretty much right. I'd run about 35 on track, depending on tyre size.

 

[I-nearly-bought-a-batty]

35/36 on the road You must be bouncing all over the place...

Stock tyres are 32.

I run 235/40/18 front and 255/35/18 rear with 29/31 (warm). That's based on a formula someone on SXOC calculated. They are pretty much right. I'd run about 35 on track, depending on tyre size.

yeah, they're quite firm

I thought the lower the profile, the more pressure required - ie big balloon tyres will run a lower pressure than rubber band tyres as there's more air volume to distribute the weight.

However, I note you run higher pressures on the track than on the road - that's the kind of info I need. Guys on the NZ Silvia site run rediculous pressures - like 40 at the rear etc!? That'll go up to 45 / 46 odd once warm whic is too much IMO. Most seem to run 34-36 which is close to my road pressure. I'm beginning to think more pressure meaning less side wall flex = more grip, less tyre distortion as opposed to lower pressure = more tyre conformation to the road = more grip.

 

[Nicely]

http://www.sxoc.com/vbb/showpost.php?p=2186226&postcount=7

 

[Endless]

Last time I went to track my pressure on street tires was 40/40 (outside temp. was around 25C), works ok for me, on street I use 33/33

 

[Yakozan]

I ran about 43psi on track with regular street tires.

normal use I run 36psi.

 

[I-nearly-bought-a-batty]

http://www.sxoc.com/vbb/showpost.php?p=2186226&postcount=7

ha - yeah I remember reading that months ago.

The main learning here is that people run higher pressures on the track than they do on the road.