This is my reasoning as to why you need to run an external restrictor:
I don't feel comfortable with the built in restrictor on the turbo. Just becuase it's there, doesn't mean it's worth a damn.
I'm sourcing the parts for you know on ATP.
The first post I did, I wasn't thinking and showed you the restrictor for the BB T28, and you have a journal bearing (duh!)
More to follow.