Trackday Tyre Pressures

[Guest Phil_neast]

Hi, my first trackday is on the horizon and I want to make sure I set the car up to get the best out of it.

 

So my questions are;

 

Stiffness of the coil overs?

Tyre pressures? I'm running R888's

 

Thanks

Phil

 

[Guest chris brown]

Start with 18 front 20 rear and adjust throughout the day to find what suits you remember no 2 cars are the same and the same with driver. It never made much difference for me the car always out performed the driver.

[Guest Ian & Carole]

One other point to bear in mind is the hotter the tyres get the higher the pressure gets, so you might find you are changing them more than once if you are on it.

[Guest zoomzoom]

Hi I've just done a track day with my zero and found starting at 16psi cold all round worked best.

Toyo R1-R on a cool track the tyre temps went up and so did the pressure to around 19 - 20 psi after a run

[brumster]

As said above, each tyre manufacturer specifies a specific temperature at which that rubber compound works best. This is your target and all you can really do is aim to get your pressures correct so that, once at operational levels, the temperature is in the ballpark. Without a temperature probe for your tyre it'll all be guesswork anyway. I can tell you what works for me on an 860Kg 205 on Dunlop cut slicks, but it won't mean one iota for your car - different weights, different tyre sizes, different rubber compound.

 

As Chris says, work it to what YOU prefer. Measure pressures as soon as you can coming off the track, and relate that to how it 'felt'. Adjust the hot pressures in small increments, go back out, see how it feels. If you find they start off good but go off towards the end, chances are they are getting too hot, which means you're generally asking too much of the tread (ie. your pressures are too high)... bear in mind the minute you stop working them they'll cool down so by the time you get a pressure gauge on them they could have dropped a couple of PSI (depending greatly on the ambient temperature and track temperature of course - rain water cools them bloody quick!)

[Guest alfaGTA]

I personally found 888's operated best at higher pressure so started cold at 22psi for track work, found lower pressure the car was too soft.

 

Back down to 18 for road.

 

Damper settings on track; HARD

[brumster]

Be aware that, I suspect, there are a lot of people using low tyre pressures as a kludge for overly-stiff spring rates in order to improve their ride comfort. Which is fine to a point, I guess, provided you don't expect the sidewalls to do much if you really lean on them (and uniform tyre wear isn't a concern).

[Snapperpaul]

Interesting points on tyre pressure and grip

The oval racers I share a barn with start with different pressures on all corners which equalise to a higher pressure during the race

To find out if your tyre pressures are right also requires taking temperatures across the surface, side to side, you can tell if pressures are high or low and I suppose clues about geometry but my brain hides at this level

[Guest Phil_neast]

Thanks guys all interesting stuff, I'll let you know how I get on as a newbie trackday virgin..

[Guest chris brown]

If you're a newbie my advice would be to just stick 18psi in them and forget them for a while. Just learn the circuit and lines and braking points. There's enough to think about there without having to think "do I need another 2 psi in the off side front tyre"

now that is good advice

[Guest zoomzoom]

If you're a newbie my advice would be to just stick 18psi in them and forget them for a while. Just learn the circuit and lines and braking points. There's enough to think about there without having to think "do I need another 2 psi in the off side front tyre"

 

That's good advice from Captain Slow :rofl:

[Guest mirach1]

the tyre pressures will increase as you get more heat in them, as previously mentioned 18 psi is a good starting point, also if this is your first trackday don't over-stiffen the dampers, leave them as you have set them for road use,do a few laps to get a feel for the car, if the back is light, ie sliding about either soften the rear slightly or stiffen the front, same applies if front pushing on, soften the front or stiffen the rear,

if the car feels like it is rolling too much in the corners turn a couple of clicks to stiffen all round.

this is only my suggestion but i reckon it will be a good starting point, go and have fun without spending too much time in the paddock changing things.

one more thing, only change one thing at a time between track time, one thing may improve it and another make it worse ,you need to know which is which