Air pressure suggestions for track?

[griffined]

I just checked the Kuhmo Ecsta Supra 712 tires I have on my R. The sidewall says max inflation is 44 PSI. Cold pressure in them at the moment is 36 PSI.

Any suggestions on what I might want to run inthem on the track during my High Performance Driving thing this weekend?

I've not really pushed the car's handling on the street yet, so I don't know what to do other than just look for signs of under or oversteer, and make a small adjustment at the track during the day.

Thanks,

Ed

 

[Andy M]

Originally posted by griffined
I just checked the Kuhmo Ecsta Supra 712 tires I have on my R. The sidewall says max inflation is 44 PSI. Cold pressure in them at the moment is 36 PSI.

Any suggestions on what I might want to run inthem on the track during my High Performance Driving thing this weekend?

I've not really pushed the car's handling on the street yet, so I don't know what to do other than just look for signs of under or oversteer, and make a small adjustment at the track during the day.

Thanks,

Ed

Ed,

First thing... buy a tire pyrometer. These are wonderful tools for helping you to determine the sweet spot for air pressures.

Second, the correct air pressure will be determined mostly by the manufacturer. For instance, the Hoosiers a bunch of us run at the track need about 30-32 pounds in front (COLD) and about 28-30 pounds in the rear (again COLD). After a few laps, you can gain as much as 8-10 pounds of pressure.

The pyrometer reading (taken immediately after a session on the track) will tell you if you have too much pressure or too little pressure. For instance, if you measure the inside, middle and outside of the front tires while they are still very hot, and the middle temp is more than about 20-30 degrees hotter than the edges?? - you need to lower the pressure a few pounds. Otherwise, if the inside temp is much lower than the outside and inside, conversely, you would ADD pressure. You get the picture.

Let me/us know if you need more information on this? The first thing I would do is find out what the recommended cold temps are for these tires, then lower by a few pounds, try a few laps on the track, check temps, and adjust as needed.

 

[kevin]

and i would suggest a pyrometer that you actually have to put the point on the tire. generally they are more accurate than the infared ones.

 

[griffined]

Thanks, I've already got an infared one I used on my RC car's heatsinks I can take on Sunday.

Ed

 

[2F2F]

> ...i would suggest a pyrometer that you actually have to put the point on the tire.

Which brands, models would you recommend?

 

[kevin]

Originally posted by ox03
> ...i would suggest a pyrometer that you actually have to put the point on the tire.

Which brands, models would you recommend?

i use a tif model 7000. i've had if for 4-5 years now. therefore, i haven't investigated what is out there now.

 

[2F2F]

I will contact TIF Instruments. Thank you.

 

[griffined]

It's the next day, and I'm still smiling thinking about my track outing. Sears Point was awesome, and the instructors that worked with me were way cool.

 

[NJ2000R]

ruh roh, another one bitten by the track bug! :thumbsup: