[Alpine TSi]

Since I got my AFC hooked up in my Galant I have been able to bring down the knock problem a decent amount. With this new found stability through the gears I have been playing with it on the freeway. I won't go into specifics as this is the open portion of the forum, but after a certain event a few nights ago, everytime I get into boost I get this sound from under the hood that goes up with RPM and boost, it almost sounds as if the turbine wheel is hitting the compressor housing or something of that nature. I only hear the sound under boost, not any other time. It does still seem to build boost like normal, but with that damn sound the entire time. I have somethings to do to it later tonight and will check for shaft play and other damage, but for now I am just getting some preliminary thoughts.

Any suggestions?