i can post view of other people too but the truth is i have experience in this field. bigger is not always better and back pressure is wanted in an exhaust system with out it youll have a bunch of unburnt gasses escaping causing a loss in power. what happens when you dont ignite all the gasses in the cylinder? you dont get the power the motor could have from the increased pressure on the down stroke from the larger combustion. for this application being an ls 2.5" piping is big especially since he wont be reving past k maybe 8k at very most with a mild build with cams. i read your post and in reality it says exactly what i said although they say back pressure isnt wanted that you have to find a happy medium or no back pressure but high velocity. with stock motors you do want to retain some of the back pressure. read my article as well


http://www.nsxprime.com/FAQ/Miscella...austtheory.htm