Using chalk to determine tire pressure Options

[ChrisReale]

On some tires, there is a triangle on the side wall by the tread that you can use to determine how much roll the tire is experiencing. How do you use chalk to mark the triangle to determine roll? I am curious also about Victoracer tire pressures. I started out at 30psi, but determined the car handles better at 26 or 27 psi. This seems a little low to me. Any comments?

[Don Wohlfarth]

Using the triangle on the sidewall of the tire you adjust pressure so there is a scuff mark to the edge of the tire from the track surface. You want to adjust pressure until you barely touch the tip of the triangle. This method works well until you start running +2 or +3 tires sizes over the oem size tire. Lighter cars don't have enough weight to keep a flat foot print with oversized tires.
Using tire temps you measure inside, center, outside. Temps should be higher on the inside, to the outside. In a perfect world the temps would be even across the tire but that seldom happens. About the best you can hope for is about 15 degrees from inside to outside with inside being the highest. Temps are usually in the 160-200 range. I run Michelin Pilot Sport Cups 225-245 X 16 on my 1900# 914 and don't see much above 170-175 even on hot days.