lets see here, shad from accuracy tuned a stock ls motor to 17 psi putting down 290 and the car ran 11.40's, its not a street driven car , its a race car so you know it gets the shit beat out of it and its perfectly fine.......i also have a ls turbo, i run 10 psi everyday and have for the last year, ive had my boost to 13 psi on race gas before and its been a year this week that ive had the turbo kit on,but i adjusted fuel of course through the AFC on 13psi just to be safe i added fuel through the rpm and drove home that night ......if my fuel pump wasnt messed up id run 12psi everyday cause my injectors are 310's instead of the stock 240's, go ahead, boost the shit out of it.......tell your buddy to turn it up, cause if its the guy im thinking of(that bought joshs car), then he better be ready when HEAT and i race cause hes getting an invite.........