Mine is extremely loud and I love it. When I leave work, my friends say they can here my turbo spooling and blowing off after I leave the lot, and am fairly far away. But, I really enjoy hearing the turbo on this car, and for the simple fact that a FACTORY Turbo, is producing 15-17 lbs of boost is just crazy as well! Be sure to reset your ECM as well.
Disconnect your Negative Battery terminal for at least 15 mins, then what I do is start the car, let it idle for 5 minutes, than I took it for a drive around town, then out on the highway for a few minutes. Just to run it through City/Highway shifts and revs. This will set the cars new Air/Fuel Ratio for the increase of air the K&N Typhoon will produce. I noticed much better bottom end in the 1.4L and better response shifting from 2nd to 3rd with the Manual Transmission. I wasn't getting near as much Turbo Lag between 2-3rd gear.