Okay, i know this topic has been covered before, but i had no luck finding any info on it in the search function. I was thinking about building my own cat-back system and welding a highflow muffler to it. I have a '94 VTEC prelude and was thinking about running a 2.5 pipe all the way back. The only other mod i have is a CAI. My question is, (1) will it be as effective as something like a Greddy cat-back as far as effeciency and hp gains, and (2) is 2.5 a good size for a 4Gen prelude??

 

2.5" is a good size for n/a. dont go any larger than that though. if you get custom pipes, make sure the are TRUE mandrel bent and not mandrel bent where the segments are crimped on the inside of the pipes. you proabably would be better off just buying a brand new or used exhaust since there are several companies out there that make these systems.

 

I'd agree my mugen is 2.5" and the stock was 1.75". Any large than 2.5" is good for turbos. Hey I wonder how a custom build up exhaust works. I mean yeah you can certainly put piping from the cat to a muffler that's it but, I know many after markets systems have some sort of resonator between the cat and the muffler.

Anyone want to elaborate on that, Did you put any sort of resonator on between the cat and the muffler.

 

**** a resonator! thats what im doing