yeah i have a type r motor with exhaust piping i think is 2.25 all the way to the muffler then the tailpipe is 1.75 am i losing power here or what? i am in the process of buy a magnaflow hi fl cat and magnaflow catback system. the new exhaust piping is all 2.25. will this gain me some more power to my type r?

 

the extra size in piping will help the breathing of your engine. Engine is like an air pump more air in more air out = more power. It shouldnt be a huge gain but with more bolt ons and mods it will pay off. you could say that this is a potential horse power gain, in the long run you have the right idea thou with the b18c5 getting it to breat