3 or 2 1/2 inch?

[BlitzPuppet]

I'm trying to decide on either getting a Flowmaster American Thunder catback 2 1/2 inch, or 3 inch. Which will I see more gains? I plan on putting a cut out right before the muffler whenever I get the exhaust, so which would I get the best gains with (BTW I am getting cold air by the end of the week, it's being shipped)

[Dominic]

On a 3.4L the 3" would be on the big side but probably wont be bad. I don't think you would see a 1 horsepower difference between the two. 2.50" should be sufficient for n/a uses [img]smile.gif[/img]

[BlitzPuppet]

yeah just to tell you, I'm not gonna do nos. My bird has an old heart. Would there be any sound difference between the two? I want my exhaust to be really loud and throaty, that's why I'm putting a cut-out on it, whenever I feel the need to make it loud, take the cap off, and cap it up before I get home so my parents don't know I have one ;)

[whiteshark]

the 3in would be a deeper tone but would decrese your backpressure so you might loose a bit of low end torque. but it would definitly sound better

[nino]

i just got 2 3/4" i pipe and kept my dynomax muffler. it sounds really nice. i dont know which would give you more hp though. have you seen the flowmaster hp/pipe diameter chart? it says 3 in catbacks are supposed to be used for cars with 300 hp+ and 2 1/2" catbacks are for cars pushing 250 hp+ and i think it said 2 1/4 for 200 hp +. but i wasnt interested in 2 1/4 so i am not sure.

i am real happy with my setup. i got an i pipe from a 93 Z28 for 16 bucks and kept my old dynomax muffler. ended up making a dynonino catback that sounds pretty darn nice. (granted i have headers y pipe, 3 in cat cat, p&p heads, airlid, cai)