Flutter dump

[senna]

Holy shit, 3 pages on "flutter"
Only OzHonda.

If it's that much of a concern then:
http://i123.photobucket.com/albums/o...8/IMG_0053.jpg

http://carphotos.cardomain.com/ride_...0009_large.jpg

I assume that because you linked pics of turbos with surge slot covers you are mistaken by what we are talking about being compressor surge, the flutter sound being discussed could be described as one form of compressor surge.

Compressor surge is when the turbo is being pushed past its normal operating RPM and it starts to "chop" the intake air and not pump it efficiently. The slots in the compressor housing allow turbulence to be created before the compressor wheel which in turn slows the intake air speed and allows the turbo to run efficiently.

Compressor surge can also happen when the motor cannot accept or i guess you could say "ingest" the amount of air the turbo is sending it. This results in the charge air "backing up" in the hotside pipes back to the compressor wheel which can cause a noise that kind of sounds like a half open blow off valve...