Sam's right. While many racers say one is striving to obtain even temperatures across the tire, Caroll Smith says baloney. His view (which is the only correct one, just ask him !) is that on bias tires you should expect to have about 10-15 degrees difference between the inner portion and the outer portion of the tread surface, with the inner portion being the hotter of the two - - with radials, relatively the same or more. I forget his reasoning, but I think it was that on most tracks you are gonna spend more time on the straights than the turns so the inner portion is gonna get hottter.
Watch for chunking or very heavy beading/blobbing in one zone of your tire. You are over working that portion. If it's in the middle, then your tires are over-inflated. If it is at both edges, then they are under inflated. If it occurs on only the inside or the ourside, it's an alignment issue - - could be camber or toe (maybe caster, though I'm not sure about that). If one portion is not beading at all, then it is not working for you and you have an alignment/inflation issue causing it. You are looking for even, fairly fine mini-rippling/beading across the contact surface of the tire. If that's what you've got, then you're good to go !
As far as the pyrometer, what kind do you have ? The laser type are OK, but do not truly give you the temps down into the rubber - - which is really what you care about. The pyrometers with the little pin-like insertion device are preferred and they should be inserted at an angle, not straight in, to allegedly give you an average of the temperature down through the rubber. To get true readings, pull int the hot pits, have a friend rush around as fast as reasonably possible and take the temps, then keep note of inner, center and outer temps (and the track temp and tire type if possible). Then save the data for future set-up, inflation and track condition reference.
You now have all this arm-chair racer knows on the subject !
