Originally Posted by Blknight.aus
Im not buying the waste gate, once your off the noise and the boost pressure begins to drop it should ease close with the loss of pressure. not shut agressively enough to make any noise...
I would buy the fuel pump relay.... or something along those lines, as you come off the loud pedal the fuel demand drops but the pump still needs to raise the pressure in the line so that if you jump on it hard again (think upshifts or double declutch downs) maximum fuel is available.
Its just a guess tho