How much boost?

[sleepydsm]

I FINALLY got my car working perfect, and I tuned for 21psi on 92 oct. It doesn't knock at all, and I've got plenty of injector left.

Mods:
20g
ported 2g mani
hks external wg
fmic
3"turbo back
2.5"tubular o2
660cc
255hp
afpr
afc
maft
3"gm maf
greddy type rs
copper sprayed mitsu metal MLS HG
arp headstuds
rebuilt motor
rebuilt head

If I remember correctly, I read something about the 1G ECUs having too much timing that it can be dangerous with "high boost"

I am curious as to what PSI I could run on a) 92 pump b)100 oct c)110+

Kath is by my house, and there is a few smaller gas stations with 100 oct near by.