I've got a DOHC ZC in my CRX. DC 4-2-1 Headers, no cat (bought it that way) and Greddy something exhaust. Here's the deal, I'm a really anti-loud person, but I want the added power (3-5hp) of the header and "performance" muffler. What would be more effective in quieting down the motor and not sacrificing alot of power: 1) Install a catalytic converter; or 2) Put a more stock muffler on and leave the test pipe w/no cat. I know the cat increases back pressure which in turn raises compression a little, thought maybe just putting a stock muffler on would accomplish the same thing... or will it kill me? I dunno, that's why I'm posting... so there you have it... thanks.

-Cody

 

Put the cat back on. It is probably hurting your low end torque badly without it and it quiets it down a great amount and keeps the air clean too. :thumbup:

Backpressure is a myth. It is flow velocity that you have to worry about. And it doesn't increase compression at all. Since it sounds like you have a stock engine, keep the exhaust on there, put a cat back on, and keep the header. If it isn't quiet enough, put a quieter exhaust on.

If you are so anti-noise, it is worth the 3-5 hp you gain from bolt ons to keep them?

 

Yea, I only tell everyone the motor is stock, and I'm not really that anti-noise, just anti enough to want to be able to hear myself talk in my own car. Thanks for the help though, I appreciate it.

-Cody

 

If u have a problem with sound, then definatelty get a cat... Some exhausts also have a resonator on the mid pipe that also helps reduce noise, alot of cat back exhausts exclude it for performance reasons... But u can alwasy get a stock mid pipe with a resonator on it...

I like mine kinda quiet when crusing around, and when I get on it I want it to growl... It used too, but I recently accuired a hole in my resonator and it sounds horrible... I need to fix that... But I dont want mine loud for the simple fact around here cops are bad about noise...

 

Replace the test pipe with a good resonator. That'll take it down a notch.

 

So, no cat and a resonator? Theres something behind where the cat is where the exhaust pipe gets bigger for about 18" then goes back to normal 2 1/2" on there... is that a resonator? Sorry for my ignorance, and thanks for the help.

-Cody

 

Yes, that is the resonator/B-pipe.

 

Ah, right on. Cat it is then. Thanks again for sharing all of the knowledge.

-Cody

 

No problem. Let us know how it goes.