tire pressure
You set your tire pressure before the burnout because you don't have time after. it should not change between rounds unless you have a leak......or has been in direct sunlight for a while.
You may have to drop half a pound because of the sun.
Unless you do a big smoky half track burn out, i don't thing it would change much.
Burn out the same way each time and set your air pressure before . Then your air pressure experiments will be much more accurate.