1NSIGHT

iTrader: (3)

I just got a manual boost controller (Grimmspeed) Its not controlling boost at all. I have been trying to turn the boost off just to see and nothing is happening. The engine has a street port and 3in exhaust; the turbo is spiting a lil bit of oil nothing serious no smoke, hits 9psi at 2900rpm. The wastegate moves and is not seized.

SpikeDerailed

iTrader: (7)

is your wastegate ported at all? whats the lowest boost the car will hit without the controller? A mbc will only be able to raise your boost pressure, not lower it. My car without a boost controller hits 11psi with a full 3" exhaust and unported wastegate.

1NSIGHT

iTrader: (3)

My wastegate is not ported. My engine is new and I just finished breaking it in. Turbo spools whenever i get on throttle. The boost cut(Haltech) is set at 9psi right now Im going to turn it up to 12psi and see what happens.

C. Ludwig

iTrader: (27)

On a ported engine, with free flowing exhaust, it's going to be hard to not have a stock turbo make 12+ psi. Boost is dictated by the pressure differential between the inlet and outlet of the turbine. You've provided more flow potential to the inlet by porting the engine and lowered pressure on the outlet side with the 3" exhaust. You will most likely need to port the wastegate at a minimum.

In my experience with these types of setups, you'll see an initial spike to around 12-14 psi when boost first hits and then it will steadily drop off as rpms rise. By 7-8000, you'll be down to about 10 psi, as the little compressor isn't able to maintain enough flow to hold any more boost.

hoosier7

To add to the above, a boost controller will never allow less boost than what the wastegate is set at.