Grover Edmonds

I have a 91 CRX with a golden eagle 85 mm sleeved block eagle rods super tech pistons 11.1 C/R, b16 hand ported head super tech Springs and retainers, Crower 2 turbo cams, corsa adjustable timing gears Set at +1 exhaust -3 intake, bosh 660 injectors, stock intake And fule rail,walbrow fuel pump,inline pro cast SS t3/t4 exhaust Tial 38 mm w/g, turbonetics 57 trim with a.63 hot side ,3" mandrel bent SS exhaaust,no cat to a magna flow muffler. tuned on Hondata S300 V2, 93 octain shell gas, [Here is my problem.I am getting lots of back pressure, 20 psi at 9 psi of boost .I cant run any timing because it starts to knock i cant increase boost either I have checked cam timing and tried several settings. I should be at 400+ hp but I am at 270hp .Dose any one have a idea why I have this back pressure problem that is causing detontion.

F22Master

Where and how is this back pressure being measured? In the exhaust?

Grover Edmonds

With a back pressure guage attached to the exhaust manifold. you drill and tap a 1/8 ntp in the exhaust near the turbo flange and install a steel line to a guage measurging psi