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track pressures all depend on driver, tire size, tire compound, alignment, ambient temp, track temp, track surface grade, relative humidity & about thirty other factors......
if you are using air (vs. nitrogen), your back tires will tend to increase about 6-10psi and your front tires will increase a little less; maybe 4-8 psi. at jaykay's cold pressures, he was likely well into the 40's hot. this will cause treadwear & temperature issues.
jaykay posted two pics; the first one shows some mild overheating toward the center of the tread. if he would have driven extended sessions, i think he would have started to see a bit of chunking here. the little blobs are just pickup from the track & are no big deal. the second picture looks fine to me.
tires are a funny thing. they will respond in a specific manner to a POINT. then, they will respond in the OPPOSITE manner. tires have a sweet spot for temp & pressure. within this sweet spot, adding pressure will increase the efficiency of the tire, resulting in MORE grip. a common misconception is that less air = more grip. this is only true when you are outside this sweet spot.
tires have two primary modes through which they develop grip. the first is friction; when you rub a material across another material, friction tries to prevent motion. the other is called mechanical keying. the tire actually deforms to the shape of the road surface. when it does this, the surface deformation acts almost like gears in a transmission. the tire and road are 'keyed' together. combined, friction & mechanical keying are referred to as 'stiction' in motorsports circles.
at any rate, pressures & temperatures effect the amount of keying vs. friction that will contribute to total stiction. when there is too much pressure in a tire, there is too much mechanical keying & the tire begins to pull apart (much like stripping gears in a transmission from too much torque). this will cause heat buildup, which will increase pressure & chunking. this cycle will continue until the tire fails. reducing the pressure reduces the keying & allows the tire to slide over the surface rather than chunk apart.
too little pressure = too little keying. the pressure is not adequate to deform the rubber to the road (lack of grip efficiency). in this case, the tire will slide over the road TOO easily; the tire will feel sloppy and the car will float a bit.
here's what happens when you run hard w/ too much pressure:
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