Originally Posted by
Karlos G
Good read chip, is what you say about chatter (surge) being harmful to the GT (BB) range of turbo's accurate, I hadnt realised this?
Yes, their shafts are thin so they suffer from movement if they are chattering too much.
I believe it was Martin hadland on here for example that had some problems with his original GT35R engine and ended up needing a larger or twin dumpvalves in the end to cure it (think it was him anyway)
Its only when running big boost though, chatter away all day at half a bar and you're unlikely to have a problem.