I didn’t really think there would be so many parts to this, but it’s getting close. After running the engine for a bit I took it to a tuner to get it mapped properly. Luckily I found Preparazioni Soretti, which had worked with the SR20, the Apexi PowerFC and D-Jetro version before, despite being a Subaru specialist.
There were a couple of things he wanted to sort out before mapping the car; these were mainly vacuum and oil lines. With the new tubular manifold, it gets very close to the intake tube and vacuum lines so he recommended moving the rubber joint on the intake pipe and the vacuum line away. The intercooler piping was cut and welded to the turbo outlet and an additional joint added (in blue). Then the vacuum line on the turbo inlet was completely moved away and under the tube, meaning it clears the manifolds completely.
The final result from the mapping session was 343hp (at the crank) and 428 Nm at 1.3bar. I quite happy with the result considering that the pressure isn’t too high and it will be a big difference to my previous setup.