I used to run my stock turbo up to 12.5 all day every day. The profec e01 has been decommissioned for a couple of years and I just put it back in today.
Ran up to 13.5 on a dozen test runs in first and second, and a couple of runs up to 16.5 psi (by accident, the profec momentarily overboosts when the gain is set too high).
Btw just installed a NIStune and it seems pretty excellent so far.
& Not badly priced if you're talented with a soldering iron.
R34GTt Auto
900mm intercooler
3" full exhaust, Hiflow cat
Nistune, GReddy Profec E01
Dualcore Atom, Centrafuse Auto
E-Manage blue for sale with all the R34 modules, ready made wiring loom. Pm me.