91-Z28-L98

How important is it to have the size of a header's collector be larger than the size of the exhaust pipe it enters? I want to run 3" piping but the largest collector size I can find it 3". Thanks for the help.

klumb15

thats fine..you don't need anything bigger than 3".....what are doing, running duals? because dual 3" is gonna have tons of flow, chances are more than what you need...3" headers to 3" pipe is no problem, i know some people like to run reducers, but there really isn't a difference...i think its a more or less a big myth about NEEDING bigger collectors than exhaust...

91-Z28-L98

3" duals is my plan. I know it'll probably be more than I'll ever need, but I don't want to go smaller and then regret it later.

klumb15

how much HP are you running? because i'm at about 400 HP, and I'm gonna be running dual 2.5's dumped before the rear axle...but i'm running bullets, if i were running mufflers i would also run dual 3"....it all depends what you wanna do, i'm gonna stick with the 2.5's for added ground clearance just because i'm sittin 2" lower than stock...

91-Z28-L98

I'm sittng at stock right now. Everything is still in the planning phase. I will be running mufflers. I hope to reach 350-400 hp to the wheels also but in case I want more power I wanted to run 3" duals. If I only lowered the car 1", how much clearance issue will I have?

klumb15

it all depends on how much you tuck the exhaust up and what kind of mufflers you are gonna run...flows have a 5" case which is real bad for ground clearance...and it all depends on how good you tuck it up..

Drkhrse89

3" duals is overkill. I have a friend that is running 460 rwhp and is running a 4" mufflex and that is the perfect size according to calculations. The only person that I have seen needing 3" duals was a 4th gen running 700 rwhp.