budlightjunkie

whats up guys, just threw on a greddy turbo kit on my eg9, fired up today, still on that greddy manage too, i have injectors 450s, but before i tuned on chrome,just wanted to see how she did, runs fine but dosnt make full boost till 5k, all stock setup, except the inner cooler kit is percision, not to big just rite, but i did leave it open down pipe could that be the problem ,need some back pressure? no check engine lights, need help, thanks for looking