A032R's

[I reply to every thread]

I know that ultimately it is a matter of personal choice but any recomendations as a starting point for tyre pressures for A032R's?

The garage had to be dissuaded from pumping them up to 29lbs! I'm on 18lbs at the mo.

 

Regular viewers will know that the car is a VX HPC (On 14" 6J wheels)

[julians]

I had aplay with pressures on mine last time I was at anglesey, I started at 28psi (what the tyre fitters had set them to) went down to 14psi. I decided that the best pressure was around 17-18psi (cold).

 

I guess it'll vary abit from driver to driver/car to car.

 

Mine is a zetec on 13 inch wheels BTW

 

Edited by - julians on 4 Apr 2002 16:05:48

[murph7355]

18's a good start point.

 

I settled on 16 (cold) in my car which evened wear out nicely.

 

I do have 13" wheels though (shouldn't make a massive difference I wouldn't have thought).

 

I once dropped right down to 10-12psi on some 21Rs. Very hot track days though and I was desperately trying to preserve the last bit of tread before the canvas (never thought to slow down mind).

[rgrigsby]

18 on 13" 185/60's is a good bet and I think works fairly well for 14" as well. Best thing would be to set them at 18 go for a fastish blat and then check the temperature across the tyres, ideally with a pyrometer but just by touch can give an idea.

 

Cheers

 

Rob G

www.SpeedySeven.com

[Johnty Lyons]

Irun mine 14*185 at 17psi or 15/16 on hot track days.

 

jj

[I reply to every thread]

Thanks Boys.

The sun is shining, schools out in 45 mins & I'm off to chuck handfuls of gravel at following vehicles (They're a bit stickier than I'm used to)

[dogvet]

I sought advice from 2 Superlight owners at Oulton last week @ a track day and they suggested 22 hot, more tends to rub the middle out. I followed their advice and even with a basic race 1.6k car it cut that mustard!

[ashaughnessy]

When recommending tyre pressures it's worthwhile saying explicitly whether you mean a hot or cold setting. The difference can be quite big.

I use about 24psi hot on the track.

[murph7355]

I personally always take the initial temperatures when cold. Different amounts of heat will go into (each of) the tyres when you're hairing round a circuit, and when you get into the pits they'll have cooled off a fair bit and in differing degrees.

 

I (perhaps wrongly) think that measuring cold is likely to give more predictable results.

 

16psi was where my tyres started to wear evenly. Which means you're getting max. contact patch on the road...

 

I noticed somewhere that you can now buy after market dashboard tyre pressure monitoring systems...must see if I can find pricing for them.

[ashaughnessy]

I was given a tip by a more experienced racer for setting tyre pressures for the track. Go out for a few laps to get the tyres fully up to temperature. Come back into the pits as fast as you can, scream to a stop and immediately pump all four tyres up to the desired hot pressure (or let air out to bring them down). You now have four tyres at the desired pressure for racing conditions.

 

When you've finished and the tyres are fully cold, check the pressures. These cold pressures can then be used next time at the same track as starting pressures and hopefully the tyres will then warm up to the correct hot pressures.

 

However, you'd need to do this for every track and different weather conditions affect it as well. So I tend to guess at the cold pressure then come in and set the pressures correctly once the tyres are hot.

 

On the road you don't get much (if any) variation in heat from tyre to tyre so setting all the cold pressures to the same value is a good idea. If you always check the pressures when fully cold then you can road test until you're happy with the settings then record the fully cold pressures and use them from then on.

 

You'll also find significant variations between different pressure gauges.

 

Absolute pressures are irrelevant except when you're following someone else's advice, in which case you need to know if they are talking hot or cold pressures.

Anthony