Ok, the title pretty much says it all, i have a full exhaust, manual boost controller, fmic, FMU, APEXI SAFC, no a/c or power steering. Im running 10 psi but it drops to 7 and sometimes six when reaching between 5 and 6k...

 

STock turbo? That's how it happens. Exhaust and intake will help you spool faster and make more boost in the midrange. At the top end though, the exhaust housing just isn't big enough. I think with a newer turbo, you may be able to stretch it out to 6k or so.

 

stock turbo lameness

you need at least a hybrid, or man up and do a full upgrade

 

yep, mine does the same thing, on stock turbo with intake/3" exhaust/fmic w/2.5" piping