I installed a gruppe-s up pipe and the helix downpipe. The turbo makes a fluttering sound as it boosts. Is this common with this particular downpipe or is there a possible loose connection? I'm not loosing boost the car is not driving eratic or anything. It acts fine, just sounds funny. Any input appreciated.

 

I just installed a Turboxs downpipe and it does the same thing.

 

Monty, please listen to myself and scbywgn. It IS normal, and yes it is the wastegate. On the old I-Club tere was a thread that went on forever because a couple of people didn't listen to what a couple of people were saying, and it became very long and dumb. Of course that's the beauty of the internet right? Enjoy your new sounding Scooby, it's the way that it should have sounded to begin with.