I replaced the stock midpipe for a free flowing 2.5" stainless Thermal turbo midpipe. This greatly reduced the already minimal turbo lag. I now get full boost(8.5psi) by 2800rpm.I also replaced the NA Enthuza muffler with a straight 2.5" pipe. Saves about 20 lbs. and it actually sounds good! The turbo itself really muffles the exhaust sound so it not really that loud. I just saw no point in paying $400 for a good quality turbo muffler just to add extra weight to the car and have an exhaust sound that I didn't like.