Has anyone done this yet? If so, how much louder is it, how easy was it, and does it mess anything up?

I did it, you can hear the turbo spool up and the stock blow off valve. The hardest thing is probably pulling out the intake silencer, its like pulling out a baby. Performance wise, i thing it picks up better in the low end but that could be a mental thing:rolleyes:

Hey dude this has been major, major topics of discussion here. Almost to a great pain and anyone on this board in the last few days to the last few months can see this exact same post. Please, I beg you to try the excellent search engine.

Here is a bone or two:

http://www.scoobymods.com/mods/wrx/silencer.php (this tells you how to do it)

http://www.i-club.com/forums/showthread.php?s=&threadid=81094&highlight=intake

Please do a search, there is so much here. So much I have yet to post a question here since I got my WRX in March. I am big time into searching.

Enjoy.