overboost
Sounds like boost creep to me. Very harmful if your fuel system can't support the extra boost. It doesn't sound like compressor surge. That's when the BOV can't bleed off the boost pressure between shifts and the pressure pushes against the blades on the turbo causing the fluttering sound like when you blow into a fan.
Well I still have a problem, the car isnt really boostin till about 4.5k, laggy.. All i did was install that HKS wastegate and adjusted the boost like 15 times. Never could get any low end, just top end. It does pull like a **** to redline, but i like to have some midrange too, any ideas?


