[L78toLT1]

Hey guys. I'm heading to Talladega Gran Prix this weekend for a 1/2 day track session. What cold tire pressure do y'all recommend that i start with, and what pressure should i dial in once the tires warm up? I've been targeting 32 psi warm. Which seems to work well with the Goodyear Supercar3's.

[kropscamaro16]

28-30 to start

[Badmojo]

Originally Posted by L78toLT1

Hey guys. I'm heading to Talladega Gran Prix this weekend for a 1/2 day track session. What cold tire pressure do y'all recommend that i start with, and what pressure should i dial in once the tires warm up? I've been targeting 32 psi warm. Which seems to work well with the Goodyear Supercar3's.

34-35 Hot should be the target. I'm not sure if that is 32 warm.


27-28 psi cold should be about right.

[Stephen12ZL1]

ditto...27-28 psi cold is a good start. Keep the pressure monitor on the info screen during your runs!

[Harpinc]

What kind of times do you guys run at TGP?

[TRZ06]

I'm sure you track guys have things dialed in, but at least for me for canyon carving and street driving, I find 33 PSI cold to be about perfect, anything less than that and you lose a little crispness in turn-in and the car just feels a little sloppy at times. With those pressures when I am running it hard up a canyon, I get to 37-38 PSI HOT and the car feels solid.

I would expect though that track driving would heat the tires even more, so I guess that is the reason for the lower starting pressures. Mine had been in that range before (from being lazy and not adding air over time), but when I do and go back up to 33 PSI cold, it feels like a different car in responsiveness and a general feeling of being lighter on its feet with less tire roll over when cornering.

One thing I was just thinking about too, is even with starting with less tire pressure, you will never gain that crispness back, even as the temps. rise from heat. Heat will increase the pressure in the tires, but not because of air volume, rather by air expanding. So a tire cold at 33PSI, will still feel more crisp than a tire that starts at 28 PSI and is at 33PSI hot.

[Og Neon]

Originally Posted by TRZ06

I'm sure you track guys have things dialed in, but at least for me for canyon carving and street driving, I find 33 PSI cold to be about perfect, anything less than that and you lose a little crispness in turn-in and the car just feels a little sloppy at times. With those pressures when I am running it hard up a canyon, I get to 37-38 PSI HOT and the car feels solid.

I would expect though that track driving would heat the tires even more, so I guess that is the reason for the lower starting pressures. Mine had been in that range before (from being lazy and not adding air over time), but when I do and go back up to 33 PSI cold, it feels like a different car in responsiveness and a general feeling of being lighter on its feet with less tire roll over when cornering.

One thing I was just thinking about too, is even with starting with less tire pressure, you will never gain that crispness back, even as the temps. rise from heat. Heat will increase the pressure in the tires, but not because of air volume, rather by air expanding. So a tire cold at 33PSI, will still feel more crisp than a tire that starts at 28 PSI and is at 33PSI hot.

I don't think I agree with what you have posted here. Understand some of it is personal feel, but 37-38 is too high for track work. The car may feel more crisp, but you will have less grip and actually gets sloppy. When my tires get to that pressure all my times go down and I can tell it is past the optimal point. Some DE sessions with certain tires I will let them run that hot because I am instructing or focusing on something other then max performance. But when I go into a time attack or autocross or where I want max everything, I have found 34 hot to be the sweetest spot.

As for you comment about pressure and PSI...I am not a super smart science guy but that is wrong data. Volume is a factor of temp. So whether you are at 33psi because of heat or 33psi because of more volume, the pressure is the same. So a tire inflated to a hot 33 or cold 33 will still be under the same pressure which will give the same performance.

But like i said, I am not a physics or thermodynamics expert but went to school with several of them, so I may be wrong, but willing to be educated.

[Tim M]

Every tire is likely different, but I just use Chevy's track supplement for my OEM GY 1LE tires...28 cold to target 37 / 39 hot pressures (front/rear) for the track.

It will be near impossible to get that high on the street, so it makes sense to start with a higher pressure. Excess tire wear if you drive on low pressure tires too on the street.

[Badmojo]

TRZ06,


The difference is at the track you are constantly at the grip threshold of the tires. What feels good on the street isn't applicable to the track running ten/tenths of the limit.



It may "feel" better, because the additional tire pressure is stiffening the dampening that the tire does. You get a stiffer ride, but you are also getting a smaller contact patch. This may be an acceptable compromise if you are NOT at the max traction threshold of the tires.


I stand by my recommendation of 27-28 psi cold and 34-35 hot at the track. This is similar to the GM High Performance Supplement for Road Course cold starting pressures (ZL1 1LE 26 psi, ZL1 28 psi.)

Originally Posted by TRZ06

I'm sure you track guys have things dialed in, but at least for me for canyon carving and street driving, I find 33 PSI cold to be about perfect, anything less than that and you lose a little crispness in turn-in and the car just feels a little sloppy at times. With those pressures when I am running it hard up a canyon, I get to 37-38 PSI HOT and the car feels solid.

I would expect though that track driving would heat the tires even more, so I guess that is the reason for the lower starting pressures. Mine had been in that range before (from being lazy and not adding air over time), but when I do and go back up to 33 PSI cold, it feels like a different car in responsiveness and a general feeling of being lighter on its feet with less tire roll over when cornering.

One thing I was just thinking about too, is even with starting with less tire pressure, you will never gain that crispness back, even as the temps. rise from heat. Heat will increase the pressure in the tires, but not because of air volume, rather by air expanding. So a tire cold at 33PSI, will still feel more crisp than a tire that starts at 28 PSI and is at 33PSI hot.

[TRZ06]

Originally Posted by Badmojo

TRZ06,


The difference is at the track you are constantly at the grip threshold of the tires. What feels good on the street isn't applicable to the track running ten/tenths of the limit.



It may "feel" better, because the additional tire pressure is stiffening the dampening that the tire does. You get a stiffer ride, but you are also getting a smaller contact patch. This may be an acceptable compromise if you are NOT at the max traction threshold of the tires.


I stand by my recommendation of 27-28 psi cold and 34-35 hot at the track. This is similar to the GM High Performance Supplement for Road Course cold starting pressures (ZL1 1LE 26 psi, ZL1 28 psi.)

Makes sense. Like I said, my experience is with street driving and canyon carving only.

[davidwarren]

I found 34-35 hot to be the ideal pressure. Over 36 and I’ve found them to get greasy. Where to start cold has a lot of variables, but 28 should get you in the ballpark and adjust after a session.

[LESS1]

Originally Posted by Tim M

Every tire is likely different, but I just use Chevy's track supplement for my OEM GY 1LE tires...28 cold to target 37 / 39 hot pressures (front/rear) for the track.

It will be near impossible to get that high on the street, so it makes sense to start with a higher pressure. Excess tire wear if you drive on low pressure tires too on the street.

^This is what I have found to hold true on GYSC3 on track. And is based on close to 1000 laps over the past year at various tracks and ambient temperatures.

[BlueinTN]

Originally Posted by davidwarren

I found 34-35 hot to be the ideal pressure. Over 36 and I’ve found them to get greasy. Where to start cold has a lot of variables, but 28 should get you in the ballpark and adjust after a session.

Same for street spirited driving. Most sensitive tire air pressure wise I ever owned and I been buying 200 TW tires since the mid 90's.



36 over your out of the ball park.

[TRZ06]

My tire pressure readouts in the display are always 1lb lower than what I set them at using my accurate dial gauge.