Exhaust questions.

[stingyboy]

okay, let me first admit to being an exhaust newbie. i know sh!t about our exhaust system and exhaust in general in all honesty.

can anyone with knowledge and a minute break it down for me?

from the engine to the muffler tip. what is stock and what is ideal?

headers, then what? down pipe? mid-pipe? then cat? then more piping then the muffler?

what parts does a cat-back replace?

as you can see, i'm an idiot who has never done ANY exhaust mods on a car. i did crawl under our cars and noticed lots of tiny piping...which can't be good. i've read that 2.5" is a good size for civics.

so basically, what should go, and what should i replace it with?

[02SilverSiHB]

Originally posted by stingyboy
okay, let me first admit to being an exhaust newbie. i know sh!t about our exhaust system and exhaust in general in all honesty.

can anyone with knowledge and a minute break it down for me?

from the engine to the muffler tip. what is stock and what is ideal?

headers, then what? down pipe? mid-pipe? then cat? then more piping then the muffler?

what parts does a cat-back replace?

as you can see, i'm an idiot who has never done ANY exhaust mods on a car. i did crawl under our cars and noticed lots of tiny piping...which can't be good. i've read that 2.5" is a good size for civics.

so basically, what should go, and what should i replace it with?

I'm kinda confused as to what you want to know. As for 2.5" I feel that is too big for any civic unless you go Forced induction, such as turbo or supercharger. I was under the car and saw that the down pipe from the header is welded to the cat, but the downpipe seem to be very big in diameter. It was bigger than any other piping under there. After the cat, the exhaust system to the muffler is bolted on, so no worries about the welding. The cat-back replaces the piping fromt the catalytic converter back to the muffler.
To get the best exhaust flow, whether it be natural aspiration (all motor) or forced induction, you should get a cai, header, maybe a down pipe with a bigger cat (even though I feel it would be a waste money for the downpipe with the cat, as I feel the piping is pretty big, but the only way to prove that is to take it apart and look for my self), then the cat-back exhaust. Then there is even more expensive and better ways to finish that off, such as port and polish your heads, intake manifold and a bored out throttle body. But these last three things are very rare for someone to do, as they can be expensive. Did I answer all your questions?

[JSIR]

the downpipe from the exhaust manifold does look very large, but it is split into two pipes internally - e pattern pipe is what they call it, but it probably still flows fine. I would definitely avoid 2.5 inch piping, I've gone with 2.25" and have lost a bit of bottom end and part throttle response , it isn't too bad but I would not like anything bigger personally. Between the catalytic converter and the rear muffler there is a resonator used to quiet down the noise further, looks like a second muffler. I think the stock header is a bit restrictive from what I can tell, probably more than the exhaust, but like mentioned above a good CAI and header will help with an exhaust. The stock midpipe is about 1.66 inches in diameter, and necks down as small as 1.5 inches in some areas, pretty tiny.