is there a significant difference in power between a 2.5" and a 3" catback? I found a borla pretty cheap, but they only make a 2.5" system. does anyone on here have it? how does it compare to apr and 42dd's 3" system?

 

.5 of an inch difference...just kidding
really no difference in power, in my opinion, no hard facts but I really do not think that will make a big diff, maybe all the brainiacs on this forum could shed some facts..
check avenue autosport for the 42 DD Dp, Good Price

 

not on stock turbo levels. Wont see much of a difference until you start breaking 300whp