Actually trying to get the boost down to 15 psi. AF/r on this pass was between 9.5 and 12.7 (12.7 at peak torque), with some slight audible ping. Not good!
I'm running a 500 cfm 2bbl Holley with a boost referenced power valve and 76 jets. I'm going to talk to my carb guy to see if we can open up the flow on the power valve and run a smaller jet. This might help tighten up the disparity in the AF/r across rpms. If I can get that high end AF/r down below 12 I think 16-18 psi would be great.
The reason the boost keeps creeping is because the turbos small internal waste gate, the gt32 was probably meant for a high pressure diesel setup - it's a twin scroll but only one side of the housing sees the waste gate, we might need to open that up as well. I'm going to machine out the exhaust housing and put in a bigger waste gate for starters.
It's going to be a street cruiser for most it's life so I want to strike a good balance. If we can keep the boost at 15 psi we should be to get a safe 400+ lbft and ~325-350+ Hp playing with timing (MSD 6530 w/ MAP sensor).