tyre pressure for track day?

[Stevil]

rpm boy I check tyre temps with a pyrometer as soon as I pull up along with tyre pressure. This gives a good idea as to what part of the tyre is working hardest. Overinflation of a tyre will show the centre of the tyre hotter than the outside. Too big a difference beteen the outside and inside tyre temps is a good indicator that you could run more camber.

As long as traffics not too heavy Racechrono on ya mobile gives good feed back to whats working and whats not.

[rpm boy]

yeah i usually just check the tyre with a infrared temp meter (pyrometer) but was wondering of there was a "scale" type device that you could roll onto after a race and measure load/heat pattern of the tyre to determine the tyre contact.......its way overboard of what i really need but just a curiosity thing really

[munkaii]

I think some racing teams, rather than using a scale will use infrared heat sensors mounted near the wheel well to observe temperature changes on the go. I'm not sure about temperature loss on cooldown, but a tyre generally loses about 1 psi on the cool down lap.

The tyre temperature at the surface is also used to estimate the approximate internal tyre temperature and with a bit of applied mathematics is not a bad approximation for tyre pressure.

[rpm boy]

might be looking into a kit that determines tyre pressure whilst driving, i assume it would work like the new cars use run flat tyre indicators and determining rotational speed depending of circumference of the wheel, not sure how accurate this will be but always good guestimation as you loose a couple degrees when comming back to pit so would give you a little extra info if correct.still would be awesome to have a machine like footlocker to show pressure and heat zones

[lil_foy]

Just adding my 2c from experience, I ran 30F 32R cold on my 205 50 15 rsr and they usually got to around 36~38 hot. I found this to be a good pressure for them, wear was nice and even.

[gbpracing]

yeah i usually just check the tyre with a infrared temp meter (pyrometer) but was wondering of there was a "scale" type device that you could roll onto after a race and measure load/heat pattern of the tire to determine the tire contact.......its way overboard of what i really need but just a curiosity thing really

One thing I look at and its quite valid is how the tire is wearing across the contact patch, this info can tell you if you have poor geometry settings which can cause over heating and wear on the inside or outside edge of the tire. Over inflation will be felt rather quickly on the race track, as the feeling will be like your on ice. I once had my tires filled with nitrogen thinking I could then inflate to the optimum pressure of 38 psi and thinking it wont increase but big mistake, their was still enough moisture in the tire to cause a positive pressure increase. After 2 laps my car started to slide all over the place, I though I had a flat at first so I came in and found my pressure went from 38 to 45psi. (Bridgestone Potenza RE55)