I have a 1992 prelude and im putting a 6'' carbon fiber exhaust on and it has a 4'' inlet and 4'' outlet i need to know the size of pipe to run from the cat. conv. thanks

 

Not to be an *** or anything, this is just my opinion. Honestly I think that muffler is a little excessive. You should find one with an inlet closer to the diameter of the pipe you need to run for your horsepower level. Unless your running a turbo I wouldn't go any bigger than 2 1/2. I think the 3in tip of my EVO2 is a bit extreme. I just got it for the sound.

 

carbon fiber??? rice!

 

not to be an *** back but i wasnt really asking for an opinion. just a pipe size

 

Well I'd try to get whoever is doing the exhaust system to reduce the inlet down to 2 1/2 and run full 2 1/2. It should be more than enough.

 

could i just run 2 1/2 till the inlet expand the tip of pipe to 4 and run it like that?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 220Lude &raquo;</TD></TR><TR><TD CLASS="quote">I have a 1992 prelude and im putting a 6'' carbon fiber exhaust on and it has a 4'' inlet and 4'' outlet i need to know the size of pipe to run from the cat. conv. thanks</TD></TR></TABLE>

Do you have a turbo? If not, you're going to lose power by going with 4" piping.

 

The 4" inlet and outlet spec refers to the OD of the tubing. If you want to fabricate a 2.5" OD exhaust, you'll need to use a 2.5" to 4" transition like this one:
http://vertexnow.com/Verocious...ducer

Is the muffler supposed to be welded to the exhaust, or is it a slip fit? If it's a weld on, you might want to look at having a flange welded onto the muffler and exhaust so you can easily remove the muffler, if necessary.

Note that if this is a street car, you'll need some resonators in the system to help quiet the exhaust. A 4" inlet/outlet straight through muffler is not going to muffle much of the exhaust volume.

 

Not try'n to sound like an *** like other people here, but I was curious!; What was the purpose of 4" piping, or rather what application is your motor that would require 4"? What kind of manifold isn't going to bottleneck that 4" cat back? I would guess turbo a setup?

Like a few here have said, it does seem excessive for a typical or basic/stock motor.

Don't worry about the e-bashers here. 50% of people here will flame you, and the other 50% will honestly try to help you. But than 25% of that 50% might be miss informed or didn't take the time to Read and Type out their or your thoughts exactly.
(I'm in the latter 50% but sometimes I don't give sound advice as well which I'll work on)

*flame away ya filthy flamers* lol

 

All you have to do is get a converter pipe from 2 1/2 " to 4".....I brought my car to a local muffler shop and they made the conversion pipe for me. It's really not that hard. (He didn't ask you if it was needed or not on his car. Just if it was possible for him to do it and how. So don't give him your opinions, just give him what he wants. Don't flame the thread.)