Of course its the dB killer

The boost was dropping off at high RPM. I asked around and it appeared that this was probably due to pressure from the gases acting on the newly ported wastegate.

So, I put in a stiffer spring, and messed with the boost solenoid control. Both of these things helped, but it seemed difficult to stop it dropping off. Really I want 8psi from 6kRPM to the red-line, maybe dropping slightly at peak RPM to avoid running the injectors at 100% duty cycle. At the moment I get 8psi at 7kRPM, but it trails off linearly with RPM ending around 5psi.

Anyway, I will remove the baffle (dB killer) tonight and see if that does the job. I am pretty confident that things will spin up even bit quicker and that the boost drop will go away as that was the characteristic before I put the baffle in.

Once it is all stable I might see if the engine (clutch really) can handle an atmosphere of boost, which is my personal target.