So many variables... and the final PSI can change with different vehicles, tires/wheels (different tires of same size can run different psi), daytime temperatures, weather conditions ... the main decision is per event... street, highway, pylon autocross, hi-speed lapping (HSAX/HPDE). For performance driving (AX.HSAX, etc)... always increase a little vs daily driving. Where the heavier weight is (front engine)... run 2-4-6 psi higher than rear. Example street/hwy... front 34, rear 32..... AX/HSAX front 40, rear 36.. (some cars/tires etc... f 45, r 40, etc). You can also dial in understeer/oversteer/nuetrality.. experience and multiple events will tell you that.l

Look at TIRE RACK web site as they offer some recommendations.

For competition events, the chalk or shoe polish is a good practice, as well as temp measurements.

NOTE: www.mcscc.org MIDWESTERN COUNCIL OF SPORTS CAR CLUBS will have 5 season HSAX events this year 2019... Blackhawk Farms Raceway (HSAX School April April 27, HSAX race #1 May 27, HSAX race #2 July 5, HSAX race #3 July 6 (that's my club's race weekend!.. www.nsscc.org hope to see you there!). Joliet Autobahn HSAX race #4 July 20. BHF HSAX race #5 August 24. All these events are on www.motorsportreg.com for pre-registration (cost savings to pre-reg!). Also, all these events are HPDE (lapping sessions) morning and competition HSAX afternoon.