exhaust

[matt_brown]

i have a 2 1/2 cat back straight threw muffler no back box its good nice crackle to it but if i change the pipe from my cat back to the manifold to a larger pipe without getting extractors will this increase the noise and crackle because more gases are getting out or will i lose power?

i think stock would be lucky to be 2 inch it seems small. ive only got the standard cat in there wouldnt this have to be changed if i went to bigger pipe??

cheers for the advice..

 

[sircruisealotVS]

i imagine your refering to the y-piece?...if you did put a larger y-piece in, it probably would change the exhaust note slightly...take away some bottom-end, and add a very small amount of top-end power.
without extractors i dont think it would be all that worth while, are we talkin about a v6 or v8 here?

 

[1991_Vn2nV]

The standard GM cats are 2.5inch in diamater, so provided you stick to that size you wont need to change the cat. And you would not want any bigger.

 

[matt_brown]

it is a v6. comes out one either side then has a support bar joining the two then enters the cat only one cat i thought later model commodore had duel cats but mine doesnt maybe utes didnt cause my mates ute is the same.

 

[sircruisealotVS]

yeah, thats called a y-piece...being a v6 there really wont be all that much difference if you got something bigger there....plus, im not 100% sure about a vy, but i know on the vs and vt with the ecotec engine you cant get "off the shelf" y-pieces because no one makes them, you have to get one custom made.
i wouldnt worry about not having duel cats, one is all you need for a single pipe exhaust system anyway.

 

[matt_brown]

yeh i dont know. my mate has a vu ute and i have vy same set up 2 and half and he has huge amounts af crackle even at low revs i need mine up to 4000+ revs and the let it idel down for it to crackle and even then its not as much as his. i took the box out and replaced it with a hot dog sounded like a tractor so that was a waste of money and time. just after another cheapish solution without going extractors because they are quite high in price.
both mine and my mates ute are stock his being manual mine auto and mine being newer model. mine beats his with ease i just want that extra crackle he has..
my box is a megaflow straight threw his is unknown brand?
is there any other solutions for noise? the louder the better