was about to say about the chatter / compressor surge thing. chatters when you lift off throttle and the butterfly closes and the remaining air cant get through the B.O.V quick enough so goes back through the turbo blades. It doesnt turn it backwards or anything, your just hearing the air being chopped up so to speak lol compressor surge is different and does damage. it happens when your on full throttle so the blades are spinning thousands of rpm and because of reasons i cant really remember from when i read this the air isnt able to go into the cyclinders so goes back through the turbo while its at full pelt. excuse the noobish tech talk lol it may be like people have said that your dv is set to stiff. Russell