Why do so many suggest arriving at track with tires overinflated?
11-05-2010, 05:17 PM
#48
Bob - this is news to me. I run stock porsche recommended pressures on my 993 4S with street tires at the track and after a long session my tires are almost always coming back way over 40psi. I have not seen any evidence that my car is an "evil handling machine" - but I will certainly lower my starting pressures if indeed there is proof that my tires have somehow become evil over 40psi.
Is there any data from tire manufacturers that backs up your information? I'm not doubting you. This is just information I wasn't aware of.
Is there any data from tire manufacturers that backs up your information? I'm not doubting you. This is just information I wasn't aware of.
11-05-2010, 05:30 PM
#49
Rennlist Member
and thats the REAL way to do it, unless you really know the "cold " pressures, as "cold " is relative and changes. 
11-05-2010, 05:35 PM
#50
Rennlist Member
No one here has even close to my cheap budget for racing, yet I have a simple solution, EVEN thought I drive to the track and carry everything with me. I learned it from the NOS days when that was legal in NASA. the 10lb NOS tank, that I still have, I use for air in the tires and any emergency air tool activity. (breaking something lose, etc with a rattle gun) the air is dry and because its NOS, the liquify point is fairly low at room temp so you can fit 10lbs of liquid air (NOS) in a pretty small bottle. it lasts all season long. I also use it at home for air for the kids bikes and air filled *****. $50 for a fill, and its always ready to go! bought a regulator on ebay for $5 bucks and its worked perfect for 10 years!
M
M
11-06-2010, 06:02 PM
#51
Nordschleife Master
The advice is still very much valid if you are tracking on street tires which are normally inflated to a comfortable street PSI setting.
I tracked my g/f's mercedes in the summer and the fuel door said:
Cold PSI: 32 psi
Speeds over 180kph +4psi
"warm tires" +4psi
(I can't remember the exact numbers, but you get the idea)
I tracked my g/f's mercedes in the summer and the fuel door said:
Cold PSI: 32 psi
Speeds over 180kph +4psi
"warm tires" +4psi
(I can't remember the exact numbers, but you get the idea)
11-07-2010, 05:55 PM
#53
Rennlist
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Larry Herman
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Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
11-07-2010, 08:44 PM
#54
Addict
Rennlist Member
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Trailer: LoadStar K550's (max psi is 50)
Car: 35 is my cold psi setting for R6's.
Truck: Girly? Perhaps. All I know is that when it got rear-ended at a dead stop by a Toyota 4Runner doing 35 - 40, it sustained minor damage while the 4Runner was totaled (the engine and hood were a twisted mess and one of the passenger doors were jammed shut). I didn't think it was too girly on that day.
Car: 35 is my cold psi setting for R6's.
Truck: Girly? Perhaps. All I know is that when it got rear-ended at a dead stop by a Toyota 4Runner doing 35 - 40, it sustained minor damage while the 4Runner was totaled (the engine and hood were a twisted mess and one of the passenger doors were jammed shut). I didn't think it was too girly on that day.
11-07-2010, 09:11 PM
#56
Rennlist Member
Too funny...
I can't believe this post has generated so many responses. The reason this "advice" is given is so that you don't have to add air when you get to the track. It has little to do with how much air pressure is recommended to actually run with on the track. You should always set pressures to whatever is appropriate for the track, regardless of what tire pressure you arrive with.
I have to believe this advice started with the autocross crowd and somehow bled over to to the big track crowd as well. It makes some sense there but not as much as it does with autocrossing. There is a much better chance of an air compressor being available at a big track than an autocross.
Scott
I can't believe this post has generated so many responses. The reason this "advice" is given is so that you don't have to add air when you get to the track. It has little to do with how much air pressure is recommended to actually run with on the track. You should always set pressures to whatever is appropriate for the track, regardless of what tire pressure you arrive with.
I have to believe this advice started with the autocross crowd and somehow bled over to to the big track crowd as well. It makes some sense there but not as much as it does with autocrossing. There is a much better chance of an air compressor being available at a big track than an autocross.
Scott
Actually, this came up a few weeks ago...
https://rennlist.com/forums/racing-a...resting+goings
It didn't get much interest here on the DE forum at the time (because it was so nonsensical), but clearly there is a lack of understanding on the subject on the part of some.
No horse in this race, just think there IS value in explaining the rudimentary basics of track tire pressures as done in many of the previous posts.
Best,
Matt
11-08-2010, 05:50 PM
#57
Rennlist Member