car wont boost over 9 psi

[TurboStreetCar]

well i might be having a similar problem. when under boost the turbo makes a loud whistling sound it has never done that before. its boosting around 8psi. could it be a boost leak or a malfunctioning turbo?

It could be, do a check for leaks it couldnt hurt. Though nature of turbos is a whistling noise.

I believe capping off the 3000 pipe where it enters the tb helps too, keeps the air from escaping into the manifold, cylinders and exhaust... otherwise its hard to build up any pressure and there will be a lot of irrelevant hissing, Right? am i missing something here?

Either way will work well enough, your method could help find very small leaks because it might be a little quieter.