Tire Pressure at the track - what's right?
04-16-2009, 08:18 AM
#1
Instructor
Thread Starter
Tire Pressure at the track - what's right?
I run my AT C5 at the local road course. I just put on a set of stock size Kuhmo MX's. What's the best pressure (cold) to run with at the track? I have heard 34-35 lbs. to prevent edge roll over versus the standard 30 lbs. cold for usual street use.
What do you all suggest?
What do you all suggest?
04-16-2009, 08:22 AM
#2
Safety Car
Member Since: Nov 2000
Location: Shenandoah Valley Virginia
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A good rule of thumb is to start at + 3 or 4 lbs and adjust from there. Adjust either up or down to keep the car handling neutral. With stock suspension and alignment you will tend to eat the outer ribs of the tires due to large cornering forces. Raising the pressures will help.
04-16-2009, 08:24 AM
#3
Le Mans Master
Thats a good place to start. Get some chalk and draw some lines on the sidewall.
After a session feel your tires and look at the chalk.
If the chalk has worn away down the sidewall add a couple pounds of air.
If they aren't too warm they are OK.
Thats what I do with my street tires.
After a session feel your tires and look at the chalk.
If the chalk has worn away down the sidewall add a couple pounds of air.
If they aren't too warm they are OK.
Thats what I do with my street tires.
04-17-2009, 02:53 PM
#4
Tech Contributor
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I would recommend running 33 front cold and 30 rear cold. Then adjust from there. With non runflats I have dropped as low as 28 front and 26 rear cold pressures.
When making your adjustments always make them in relationship to your cold temps. IE: If the original front cold pressure was 33 and the hot pressure is 40 and you want to reduce understeer you might make small reductions of a pound or two. Dropping the hot pressure from 40 to 38 is the same as dropping the cold pressure from 33 to 31 so the next time you are on cold tires you can determine the best pressure to start with.
Bill
When making your adjustments always make them in relationship to your cold temps. IE: If the original front cold pressure was 33 and the hot pressure is 40 and you want to reduce understeer you might make small reductions of a pound or two. Dropping the hot pressure from 40 to 38 is the same as dropping the cold pressure from 33 to 31 so the next time you are on cold tires you can determine the best pressure to start with.
Bill
