Are very personal setting is tyre pressure ;)

The lowerer the tyre pressure the better the grip to a degree ;) but the wear rate inreases significantly :( Dropping tyre pressure by 10 psi might add 0.5secs to you lap times ;) but the tyres may only last 3 laps :rolleyes: OK if trying for Pole position :D and no real gains if you buy the tyres IMHO IIRC etc

Normally I add 10 psi to give a more direct turn in and more importantly to minumise the tyre wall wear :D then recheck pressures after 4 laps or so when tyres are hot ;)

Tony

Edited for Spoolink mistack

[Edited by T5NYW - 9/2/2003 11:57:24 PM]

I was told it best to rub chalk on the outer edged and side walls of you tyres, then do a fast lap and see if it's rubbed off, if the majority has rubbed off then you know you need to add a little more air in..

Next track day i do, i will have a nice amount of spares like brake pads and tyres (will probable buy to wheels/tyres for track use, as they wear soo fast) :)

[Edited by Monkeh - 9/5/2003 1:49:22 PM]

Does anyone recommend/know the optimum tyre pressure for an STi8. I am at Trax this weekend and not sure whether to change or not?

I would have thought 36+ psi

I used to put my alfa's 16" tyres to 40 when on the track

Thanks for the advice

42,40 F/R usually for me and check after 3-4 laps, left front will be higher due to scrub (particularly at Silverstone)adjust it so that the fronts are equal again.

Having said that AFAIK Trax is a fairly pants trackday arrangement anyway ( but havwe never been to it),with lots of cars on track and 15mins or something? So maybe just whack them up a bit and forget about it.
Don't whatever you do reduce pressures :rolleyes: Fine in a 4x4 off road, daft on track in a scooby.

At a recent airfield day, i was running 37-38 front, 34-35 on rears, and this was probably not enough as I got severe tyre wear on the front right tyre (anticlockwise circuit).

http://homepage.ntlworld.com/matthew...hotos/tyre.jpg

http://homepage.ntlworld.com/matthew...eZoom.jpeg.jpg

Would suggest that you start at something between 38 and 40 to begin with, checking temps and wear at the end of your short circuit sessions and adjust to find a balance.

I thought that putting that amount of air in the tyres was too much, but with hindsight I probably didn't put enough in for the tyre wear I got (I know for next time!)

SB,

I run 34 all round on my STi 7 on the road!!! I would go to at least 40 on the track (cold). Also, it's worth noting, with that much tread on your tyres, they are likely to overheat on the track quite quickly......

Matt :)

Must look better in the pics than in reality...only a few mils above the rubber wear indicators.

One more track day at the most I think b4 looking at a set of road legal slicks...(plus the airfield took a fair few 'chunks' out here and there as well)

The advice to increase pressures is strange to me - on bike days I always drop the pressures a few psi for grip...

On a bike you don't have the problem of tyre deformation as bikes are pretty much as suited to the track as the road. On a road car, the road tyres are not suited to the track and so need to be inflated more to harden them up, at the expense of grip, of course :(

Matt :)

Any one ideas about pressures for sprinting. The circuits in Scotland are kart tracks with tight corners and the understeer is a problem. I've run at 40f, 38 r to save on wear but would like to decrease understeer if poss. Would lowering the front pressure do anything helpful.

John