Could a small adapter be screwed in to the map sensor port that would sort of block boost kinda like a boost elbow, and then the map sensor could use an adapter to fit into the boost blocking adapter in the original map sensor position. The ECM wouldn't see much boost and would be adding fuel even though it would actually have quite a bit of boost and this would be more power or will this not work, or has somebody already tried this.

 

I see it has already been done by using a pressure regulator, there is no defueling because the ECM doesn't see over 20 psi

 

Don't forget the ecm needs to see boost to add more fuel with the air. It just can't see more than 20 psi.