i got my mufflers installed on saturday with custom piping. From the catback they did 2 1/2 piping and where it splits they ran 2 1/4. i saw that i lost some low end power but gained high. As for the sound, it sounds soooo good, a lot better then what i expected. The mufflers that i am using are the one that illegalakkord was selling. They were the apex'i n1 with a 4 inch tip i believe. The muffler itself is small and skinny, so it does look bad like the other n1's that are big canisters. i will try to post some pics and sound clips if i learn how to do it. hopefully i do so you guys can hear my exhaust and let me know that you guys think. i will probably go to the track next weekend to see if my mph got better and if my 1/4 mile time improves.