too many variables to even guess what he's using
or why ?
need a bit more info goals, style & size of tires, class
street driven or strictly drag car etc.
opinions will vary
ask 20 people you'll get 15+ (or 20) differing answers
& 1/2 will be wrong, for your specific combo,
the day or track conditions
anywhere from 6-psi to as much as 9-psi with a bias slick
to 20psi with a Drag Radial
(hell I ran a lil' as 4 psi on Bias/33x15 in my altered, with liners & slicks screwed to the rims)
or anywhere in between,
I've been 6.69 @217 on 6 psi/bias 33x15 beadlocks on 2650# (35x17 latter on 2800#)
tube chassis car Top Sportsman/Outlaw P/S car,
no issues, handled fine left straight & level, hooked hard
stopped fine, especially with chute/s
I've been 9.77 @ 135 NA street/strip car, I drove to the track
or 8.58 @ 156 both on 315/60 Drag radials with just a rollbar,
dbl adj. Lambs, tubular UCA/LCA & a built/stroked 383/489cid on 300 shot N2O
on Calvert/CalTracs in a 3250# RR, 3500# w/driver on DRs @ 14-21 psi,
depending on conditions, RAD, gears & shocks or track prep even
There's not just 1 specific psi (settings) that works, for any tire or all cars