Street tire pressue for MT s/s

On my van at the strip I run 255/60-15's @ 16-17 psi, and after a few seconds (just till they smoke) in the burnout box they then always dead hook. On the street I'm still experimenting with the best psi. They are easy to light up at normal street pressures, will be trying the lower 20's and see how the do. I like 'em though.
A lot of rear wheel weight to help !!