Sanz

Yes, the cat back will really affect the sound. a 2.5" exhaust will have a much deeper tone, and will be louder than the stock exhaust.

I reccomend if you do that, that you get a high flow cat of the same diameter as the new exhaust you are buying. If you go with a 2.25" exhaust, go with a 2.25" cat.

Gleek Tibby
One word of warning. Do a search here on Pacesetter. The pacesetter cat backs have a three bolt flange. Most tibbys have a 2 bolt flange, so the pacesetter unit does not work on most tibbies. If you don't know which you have, crawl under your car and peek. Right after the last cat/resonator, see if you have a 2 bolt connector or a three bolt. If you have the 2 bolt flange, the pacesetter unit will not work on your car.

 

Random,

Thanks for the advice! Ok, I believe I did it right then. I got a 2.5" CC and the 4-2 SR-heder, which I believe is 2.5".

Just one more question, where can I get catbacks that are 2.5" in dia.? or do most manufacturers sell them in diff. sizes? rolleyes.gif

Ooopss...I meant 4-1 headers.

[EDIT: to place second post in first]

[ February 04, 2002: Message edited by: Random ]

 

Please don't double post, just edit your first post by clicking on the icon.

Yes, cat come in many different diameters. Stick with the same diameter cat as your exhaust. If you go 2.25" get a 2.25" cat. If you go 2.5", get a 2.5" cat.

Do NOT go larger though. A larger cat will allow the exhaust gas to slow down too much, and that will create MORE backpressure than a cat of the proper size.

 

random, if you have a header(2.5") and a 2.25" exhaust, shouldn't you do a 2.5" cat or should you do a 2.25" cat?

 

I would go with a 2.25" cat. The cat "opens up" inside, so having a 2.5" inlet and a 2.25" outlet would put the bottle neck inside the cat. I would put it just before the cat. Going from 2.5" to 2.25" will speed the exhaust gas up (same volume moving through a smaller pipe will speed up to maintain flow) as it passes into the cat.