I loose power frome 4500 to 5500 rpms couldn't work it out on the dyno. I'm runing stock turbo and injectors (91 13b turbo) A auromotive fuel pump and fuel regulator at 48 psi. don't know what to do please help. thanks

 

what kind of ecu are you using? if it's stock what 's you afr like? that should tell you what's going on too lean or rich. also what boost level are you running with 48 psi of fuel? i think there is a rule for every pound of boost the psi raises 1 psi above setting at idle, not too sure but check afr though.