i know you need to replace the whole system to get any increase in performance all i was saying is that lots of jap cars look and sound great with the big bore pipes on, and please don't try and put me down without knowing anything about me i made a harmless comment and you're making me out as some dumb ass. when i put a big bore exhaust on my car i replaced the whole system manifold back so i may not know as much as you as you are some big tuning guru but i know a little bit, i also know about how much car company's spend on development as i am an apprentice at ford so part of my training is learning about that. i love jap cars always have, always will would love to have a honda civic vti or a crx at some point