Originally Posted by TopgunZ

Boost is a measure of restriction in the manifold, where the source is taken. Actually, you dont "want" high boost numbers because that means your engine has more air in the manifold than you can get out the exhaust. Its essentially unused power. By opening up the exhaust you get to actually move that boost through the system, ultimately lowering your psi reading, but making more power. Thats a good thing.

Think of it this way. You take a large turbo and put it on a 6.2L V8. You are going to make 800whp at 10psi. Take that same turbo and put it on a 2.0L and you will make 400whp at 30psi. There is literally just less boost being consumed by the engine since it cant move enough air in and out fast enough, but the boost numbers are still much higher.