He has a 1.6..... Don't go above 2" on the piping.nss200sx said:get the N1 style muffler...wit 2 1/4 in piping run from the catback...and remove the resignator....it gave my car a nice deep but aggresive sound....i havent had n e complaints yet bout it sounding shitty at all...sounds great
Read the tech section on Sentra.net and the back issues of NPM
http://www.sentra.net
http://www,nissanperformancemag.com