If you pull the wastegate hose off entirely, your boost should go to maximum that it can do.

If you can't get good boost in this position, then:
1. your wastegate valve is boogered (that's a technical term for cracked/open)
2. your turbo isn't compressing
3. you have a serious leak in the intake manifold so nothing is holding pressure

__________________
Cheers!
Scott McPhee

1987 300D