If I blip the throttle quickly and rev to 2000 RPM, when the engine revs down, I can here a slight "chirp" noise emitting from the muffler. I assume this is due to the turbo's turbine spinning? Is this normal?
Wow this has to be like the 5th time I have answered this. I have never said it before but please learn to use the search button, it will help you a lot. There is tons of info on this fourm and the search is the only way to get to 99% of it.
Anyways, the stock exhaust makes a chirp noise, its completely normal, nothing to worry about. When you upgrade your exhuast it will turn into a soft poping noise, which is very cool and sounds really nice. I don't know why the stock one makes chirps, guess its all in the design of the axel back.
heh - I just swapped my stock exhaust back in and noticed the chirp as well. I never noticed it before. I searched and found this thread (Among others). Glad it was here because I thought I fcuked something up when I removed all my stage4 stuff.