Track day tire temps, Sport Cup 2s
07-18-2017, 12:02 AM
#1
Racer
Thread Starter
Track day tire temps, Sport Cup 2s
Hi All,
Track day this past weekend with NASA at UMC (Utah Motorsport Campus), HPDE1. Sport Cup 2s. "Raquel" has about 1600 miles on her now. Track surface by 1000 was 140F. Ambient at about 104 by 1500. FWIW, ran 4 20min sessions during the day, 1 1/2 -2 hours between, with water temps peaking around 260, running A8 sport mode, pushing my limits but trying to learn and not worry about a hero lap. This was my second day on a track with a car since 1972. On paper, none of the other cars out there should have been able to pass me. None did. One guy in a Spec Z was pretty equal in the corners but on the short straights.......Raquel took his lunch money
Decided to check tire temps with infrared gauge. Had GM rec alignment settings.
End of run temps were a little higher on the front right, lots of left hand turns on west track, and I feel a little more comfortable using the brakes than the throttle. Anyway, I am learning.
Tire temps were 160-170 inside, tapering a little, 10-15 degrees, to the outside all around, a little higher in front.
What should I expect? I would have thought the outer edge would be higher.
Do I need to drive faster, align with less negative camber, more or less pressure (34-35 hot was what I set).
Maybe I should just forget it and drive. I had a great time, and didn't have any car overheating messages/power reduction. I, on the other hand, was getting pretty hot
Track day this past weekend with NASA at UMC (Utah Motorsport Campus), HPDE1. Sport Cup 2s. "Raquel" has about 1600 miles on her now. Track surface by 1000 was 140F. Ambient at about 104 by 1500. FWIW, ran 4 20min sessions during the day, 1 1/2 -2 hours between, with water temps peaking around 260, running A8 sport mode, pushing my limits but trying to learn and not worry about a hero lap. This was my second day on a track with a car since 1972. On paper, none of the other cars out there should have been able to pass me. None did. One guy in a Spec Z was pretty equal in the corners but on the short straights.......Raquel took his lunch money
Decided to check tire temps with infrared gauge. Had GM rec alignment settings.
End of run temps were a little higher on the front right, lots of left hand turns on west track, and I feel a little more comfortable using the brakes than the throttle. Anyway, I am learning.
Tire temps were 160-170 inside, tapering a little, 10-15 degrees, to the outside all around, a little higher in front.
What should I expect? I would have thought the outer edge would be higher.
Do I need to drive faster, align with less negative camber, more or less pressure (34-35 hot was what I set).
Maybe I should just forget it and drive. I had a great time, and didn't have any car overheating messages/power reduction. I, on the other hand, was getting pretty hot
Last edited by desmophile; 07-18-2017 at 12:44 AM.
07-18-2017, 01:45 AM
#2
Hi All,
Track day this past weekend with NASA at UMC (Utah Motorsport Campus), HPDE1. Sport Cup 2s. "Raquel" has about 1600 miles on her now. Track surface by 1000 was 140F. Ambient at about 104 by 1500. FWIW, ran 4 20min sessions during the day, 1 1/2 -2 hours between, with water temps peaking around 260, running A8 sport mode, pushing my limits but trying to learn and not worry about a hero lap. This was my second day on a track with a car since 1972. On paper, none of the other cars out there should have been able to pass me. None did. One guy in a Spec Z was pretty equal in the corners but on the short straights.......Raquel took his lunch money
Decided to check tire temps with infrared gauge. Had GM rec alignment settings.
End of run temps were a little higher on the front right, lots of left hand turns on west track, and I feel a little more comfortable using the brakes than the throttle. Anyway, I am learning.
Tire temps were 160-170 inside, tapering a little, 10-15 degrees, to the outside all around, a little higher in front.
What should I expect? I would have thought the outer edge would be higher.
Do I need to drive faster, align with less negative camber, more or less pressure (34-35 hot was what I set).
Maybe I should just forget it and drive. I had a great time, and didn't have any car overheating messages/power reduction. I, on the other hand, was getting pretty hot
Track day this past weekend with NASA at UMC (Utah Motorsport Campus), HPDE1. Sport Cup 2s. "Raquel" has about 1600 miles on her now. Track surface by 1000 was 140F. Ambient at about 104 by 1500. FWIW, ran 4 20min sessions during the day, 1 1/2 -2 hours between, with water temps peaking around 260, running A8 sport mode, pushing my limits but trying to learn and not worry about a hero lap. This was my second day on a track with a car since 1972. On paper, none of the other cars out there should have been able to pass me. None did. One guy in a Spec Z was pretty equal in the corners but on the short straights.......Raquel took his lunch money
Decided to check tire temps with infrared gauge. Had GM rec alignment settings.
End of run temps were a little higher on the front right, lots of left hand turns on west track, and I feel a little more comfortable using the brakes than the throttle. Anyway, I am learning.
Tire temps were 160-170 inside, tapering a little, 10-15 degrees, to the outside all around, a little higher in front.
What should I expect? I would have thought the outer edge would be higher.
Do I need to drive faster, align with less negative camber, more or less pressure (34-35 hot was what I set).
Maybe I should just forget it and drive. I had a great time, and didn't have any car overheating messages/power reduction. I, on the other hand, was getting pretty hot
So, your car did not overheat at air temps of 105 and you have an A8?
07-18-2017, 07:51 AM
#3
Short answer: don't worry about it. Long answer is that reading tire temps with an infrared gauge isn't very effective. The IR gauge just reads the surface of the rubber which cools too fast for an accurate reading.
You need one of the probe types that can get the temp beneath the surface and even then you need to read immediately after coming in off a hot lap. Finally, I've heard both Mike Levitas (Porsche GT3 Cup champ and Rolex 24 winner) and Randy Pobst say that tire pressures aren't that great of a setup tool.
You need one of the probe types that can get the temp beneath the surface and even then you need to read immediately after coming in off a hot lap. Finally, I've heard both Mike Levitas (Porsche GT3 Cup champ and Rolex 24 winner) and Randy Pobst say that tire pressures aren't that great of a setup tool.
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thebishman (07-18-2017)
07-18-2017, 08:27 AM
#4
Racer
Thread Starter
Track day with Z06/A8
Air temp at the track when I left at a little after 5PM was 104. That was the hottest time of day. Running sport mode in auto half the last session and shifting with paddles at 5000 half the session, the car did not show me signals of power reduction. Water temp about 260. I was pleased I could drive that hard for 20 minutes without a problem. Others can certainly drive the card harder I am sure. Just my experience FWIW.
OK, I will stop worrying about tire temps and just enjoy the ride.
OK, I will stop worrying about tire temps and just enjoy the ride.
