john blutarski
Member
- :
- 2004 Subaru WRX STI
You will hear the compressor wheel stall out from pressurized air going back against it.. its kind of a pff, pff, pff quick short frequency sound. This is different from wastegate flutter which is when the wastegate door is fluttering open and closed trying to maintain a certain boost level. Flutter usually occurs at low boost on/off throttle situation. Surge is most noticable when building boost from a high load at lower RPM in a high gear like 6th for example. You shouldn't do this anyway but if you were to lay on it around 3k in 6th, build boost and then let off right away at say 4k, you should hear some surge depending on the valve/spring you are running.
