Brendon, try getting a straight pipe through first before you buy anything . Do it like wat pixels says. And see how you go.
<y Nismo muffy have a resonator and its abit loud at times when low rpm but hey a lot of people whom heard the sound before that it sounded like a porsche.
try a straight pipe through go to a junk yard and get a piece a scrap 3" and weld it on and see how you go first.