Put the restrictor in today, it has reduced boost to 1.2bar now but still over boosting, I put it in the very bottom pipe, one that leads to my induction kit?
I think the hole in the restrictor is bigger than 1mm, so while I am at work tonight I will make one with a 1mm hole in it and try that.
If I can't stop it over boosting what would be my best thing to do next? maybe that little gizmo you have in your STi?