Boost,

I've kinda followed along with your development of the Turbo Buick and appreciate all the information that you have shared. Since you have pretty much zeroed in that the throttle closing is a form of protection which is most likely due to the predicted torque value ..... about the only thing I can offer up is what some of the old hacks used to have to do.

For the old LT1's (opti spark, not DI engines), we didn't have any COS's or any 2 bar, 3 bar stuff to play with. One of the work-arounds was to 1/2 all the tables so that you could use a 2 bar MAP (there is more to it, but that's the jist of it). One of the other things that you had to do was divide the displacement of the engine by 2. My guess is that if you went through all of this (there are quite a few tables that you would have to play), the "predicted engine output" should also go down. With the ECM's (ECM and TCM) seeing the lower predicted torque .... that hopefully should limit the amount of throttle closing you are getting.