I have a 1999 WRX type RA the problem i am getting is a bit strange. In 5th gear when i put my foot down the turbo seems to spool up OK but as it continues it starts to make a "fluttering noise" its hard to explain really.In the lower gears it seems OK, still pulls no problem. I found a hole in the turbo inlet pipe and had this changed which i thought was the problem but unfortunately no change. Any ideas anyone?