Tire Temperature
Rennlist Member
Joined: Mar 2006
Posts: 1,388
Likes: 5
From: Damascus, MD
That used to be a good way to measure the resulting effects of tire pressures. And while it can still be useful today, modern low profile tires don't seem to roll over as much/easily as taller tires of days gone by. You can still use chalk to validate, but it seems to require a much larger change in pressure nowadays to cause a significant change in the chalk line. IMHO, better to find your optimum range, and then use a guage to periodically check the pressures (most tires nowadays seem to operate somewhere between 32 & 36 cold; 34 & 40 hot).
Three Wheelin'
Joined: Feb 2008
Posts: 1,848
Likes: 5
From: T.C. Michigan
I had made a comment on another thread you had started about purchasing tires at the track about recording data.
Knowing tire pressures and adjusting and comparing must be done in relation to ambiant air temperature. While I agree that it's not important to record tire temperature, you cannot ignore air temperature.
Simple Kestral brand guages (miniature weather station) will provide you a with air temp, relative humidity, wind speed etc.
Your concern should be starting tire pressure and immediate off track pressure. Initial pressure settings will change dependant on air temperature and type of tire. Pressures coming off the track (hot) should be the optimum max pressure for that tire. As the tire heats the pressure increases.
Knowing tire pressures and adjusting and comparing must be done in relation to ambiant air temperature. While I agree that it's not important to record tire temperature, you cannot ignore air temperature.
Simple Kestral brand guages (miniature weather station) will provide you a with air temp, relative humidity, wind speed etc.
Your concern should be starting tire pressure and immediate off track pressure. Initial pressure settings will change dependant on air temperature and type of tire. Pressures coming off the track (hot) should be the optimum max pressure for that tire. As the tire heats the pressure increases.
Rennlist Member
Joined: Mar 2006
Posts: 1,388
Likes: 5
From: Damascus, MD
But, bottom line.....have fun!
Race Car
Joined: Dec 2004
Posts: 3,991
Likes: 48
From: GOD's waiting room. <br> SoFla
also keep in mind parking the car in the sun.
easily 2 lbs different on the tires in the sun vs the shaded sides.
IMO, its the hot temps you really want to look at. and work back for the next session.
also the differential front to back. If I want loose (autox) I make that more than 4# different.
but I'm not sure how much any of this really impacts a street tire. they just seem to work in a much wider range.
