Tire Hints

by Jerry Sutton
At the '95 Parade, I caught up with Dave Saunders of Michelin/BF Goodrich. It was easy...he was on crutches. Lee Wilkins some time ago reported learning via the Internet that brand spanking new COMP T/A R1 tires needed to be heated up exactly one time, then allowed to rest for at least 24 hours. But no one had said how hot to get them. Dave says they need to reach a temperature in the range of 160 F to 200 F. He felt that it would take 4 laps on the MineralRing to get such a temperature. During the tire panel session, all the technical representatives on the panel agreed wholeheartedly that you must use a pyrometer to guide tire pressure adjustment. They use cold tire pressures as a starting point, then depend upon the pyrometer. One soul said he did not own a pyrometer and asked what hot pressures he should use. The panelists replied they can't judge anything by pressures, GO BUY A PYROMETER.

So what can a pyrometer tell you?

Go drive and get the tires hot, then:

  • Check the temperatures across the width of each tire...it they are not uniform, your suspension geometry and/or tire pressures are wrong. If the tires are hotter in the center, let air out. If the tires are hotter at the edges (especially the outer edge), add air.
  • Check the temperatures of each tire...if they are not uniform (side-to-side), your alignment is wrong (specifically, the weight at each tire is different). Note that this must be checked after an equal number and type of right and left turns...a symetyrical figure-8 is perfect.]