It takes at least a month to 2 months to break in. Just wait, In a month you will not beleive how much louder it will be. It will sound INCREDIBLE. My AA exhaust was also very quiet at first but once it broke in.... I was like "DAMN". It takes time. And performance will increase as well. Just wait and you'll see. Thought i'd let you know what to expect. Congrats, hope you enjoy it.

I just received my AA Gen 3 DTM exaughst from AA on Friday. The installation was pretty easy. My friend and I did it in about an hour and a half. Taking the old exaughst was the most difficult problem.

Anyhow...the exaughst at first didn't sound really loud, nor did it have a low grumble. Probably because I needed to break it in. Well I did a little bit because I drove around in my car all night going out. Then the next mourning went to the SF Bay M3 meet. While driving up Mnt. Hamilton...I think this thing just broke itself in...LOL The exaughst note is exellent. Normal cruising speed it is a little bit louder than stock. Then if you put the pedal into the floor, omg it is loud and has a terrific note. I highly recommend this exaughst if anyone if trying to buy.