DV Delete done today, hacksawed off one of the sockets from an old spider wrench and used that as the bung. Now got lots of Thhhrrrrwwwwwdddd rather than Pssssssssttt.
Has to be plasibo affect but felt slightly slower, and boost didn't seem to be pulling quite as much, But then it was a warm day, and first time in a long time I have given it a proper spanking for a fairly long period of time...... Its been Ring checked as best I can
Much better but now a different noise at similar levels at similar break points. Will run with it for the ring and see how it goes