Tire pressure at the track: what do you run?

[Lunares]

What kind of tire pressures do people use while running autocross or track?

I'm planning on around 35 PSI for my RE71Rs

 

[coleAK]

Great choice for track tires. Start by using load tables, here are some. Toyo put it out but they are not Toyo specific.
https://www.toyotires.com/media/2125/application_of_load_inflation_tables_20170203.pdf

Personally I would start at what ever the load tables recommend. And go down by 2 psi increments cold pressure if needed based on feel and wear. Also probably want to keep it within ~10% of what the load tables tell you.

 

[kbecks13]

What kind of tire pressures do people use while running autocross or track?

I'm planning on around 35 PSI for my RE71Rs

This is always a big question that comes up at Tesla track events since the car is fairly heavy, so it's tough to use other cars as a baseline.

FWIW - Randy Pobst requested 28 PSI cold and i thought he was insane, but it turns out that's actually not too crazy. I try to stay around 36-38 hot, so try starting around 30 PSI cold and keep an eye on it as you run and they warm up. I've done about 5 track days in the Model 3 with RE71s and found good results the lower i went in pressure, so i think its fairly safe to say you absolutely don't want to be over 40 hot.

I still think starting at 28 would be a bit low, but i started at ~32 and had to let a decent bit of air out throughout the day to stay in the 30's when hot.

Keep in mind the more aggressive your car is set up in terms of camber will mean you can go lower with tire pressures though (my car is lowered and has more aggressive camber than stock).

 

[beastmode13]

This is always a big question that comes up at Tesla track events since the car is fairly heavy, so it's tough to use other cars as a baseline.

FWIW - Randy Pobst requested 28 PSI cold and i thought he was insane, but it turns out that's actually not too crazy. I try to stay around 36-38 hot, so try starting around 30 PSI cold and keep an eye on it as you run and they warm up. I've done about 5 track days in the Model 3 with RE71s and found good results the lower i went in pressure, so i think its fairly safe to say you absolutely don't want to be over 40 hot.

I still think starting at 28 would be a bit low, but i started at ~32 and had to let a decent bit of air out throughout the day to stay in the 30's when hot.

Keep in mind the more aggressive your car is set up in terms of camber will mean you can go lower with tire pressures though (my car is lowered and has more aggressive camber than stock).

Your entire post, this is what I read "Randy Pobst requested 28 PSI cold"..noise...

 

[SammichLover]

Where did Randy's tires settle at when at full operating temp? And yours for that matter. Especially with Autocross you have opportunity to maintain the PSI at a target as the tires warm up. So I tend to start at my target temp and bleed out as I warm them up. On a road track it is a bit different, still I tend to think about it in target temps and have been coming in 1/2 way through the first session to check PSI, while doing a quick check of lug nut torque to make sure I didn't screw something up.

P.S. This also means that I have to do a serious refill of two of the tires between track days. If rotate front to back for each use, as needed to keep wear even, then you can't just start cold what you left the tires at because the fronts tend to get heated up more than the rears. That means you bleed out more air from the front wheels as maintain the PSI, and at the end of the day will have a lower mass of air in the front wheels than the back even if you have the PSI square.

 

[Lunares]

Where did Randy's tires settle at when at full operating temp? And yours for that matter. Especially with Autocross you have opportunity to maintain the PSI at a target as the tires warm up. So I tend to start at my target temp and bleed out as I warm them up. On a road track it is a bit different, still I tend to think about it in target temps and have been coming in 1/2 way through the first session to check PSI, while doing a quick check of lug nut torque to make sure I didn't screw something up.

P.S. This also means that I have to do a serious refill of two of the tires between track days. If rotate front to back for each use, as needed to keep wear even, then you can't just start cold what you left the tires at because the fronts tend to get heated up more than the rears. That means you bleed out more air from the front wheels as maintain the PSI, and at the end of the day will have a lower mass of air in the front wheels than the back even if you have the PSI square.

What do you use to measure / bleed?

 

[beastmode13]

What do you use to measure / bleed?

I have a 12 year old version of this, still works like a champ. Having a bleeder button helps tremendously in bleeding it accurately.

https://www.amazon.com/Longacre-504...ocphy=9031921&hvtargid=pla-492552520469&psc=1

 

[SammichLover]

I have a 12 year old version of this, still works like a champ. Having a bleeder button helps tremendously in bleeding it accurately.

https://www.amazon.com/Longacre-504...ocphy=9031921&hvtargid=pla-492552520469&psc=1

I have exactly that model. The bleeder button makes it so easy. I didn't bother with the oil-filled version. They supposedly last longer (are NOT more accurate) by shielding the instrumentation from foreign objects. However that strikes me as paying double price for just another thing to to go wrong and leak in my car .

The swiveling nipple at the tire end makes it easy to get it on for a good seal and the hose allows you to reach in and around to wherever your valve stem is while still easily reading the gauge in the light of day.

There's an equivalent from another company, the name escapes me now, that I've see others use that has a large blue housing on the gauge with a much larger numbers on the scale. I used one once, also seems top notch, also. This black marks on white background scale though seems to work very well, I can read it accurately even without my Grandpa Glasses (I use +1.75 reading glasses).

 

[beastmode13]

One more cool thing about the Longacre gauges. The white face is coated with luminous material that glows in the dark after some sunlight charging.