Thanks for the replies.
So I have backed off the nuts on the actuator arm and this has helped a little bit but still getting the same noise at around 4000rpm. Today I will undo the nuts and do them finger tight and see if that helps.
Any other ideas would be greatly appreciated. The turbo is a pumaspeed x37 hybrid 20% bigger than standard. I was told the map wouldn't be a problem, it would just not run at its full potential. It wasn't an issue with the standard actuator boost just seemed to level off after 4000rpm