Determining exhaust inlet/outlet size

[Marc93lx]

When I install my header I figured I might as well upgrade the whole exhaust system at the same time. So my question is, when ordering catalytic converters, resonators, and such how do you determine what size inlet/outlet you need? Say Im running 2 1/4" piping, do I get 2 1/4" inlet/outlet, or should I go a size bigger: 2 1/2", or a size smaller: 2"?

[ne3ek]

well you're talking a whole 1/2" difference dude. I beleive they sell small sections of pipe that are slightly larger so that you can connect the two pipes and clamp them. Or you get them welded. I haven't hit the exhaust of my car, but that was my understanding. I'm sure you get the cat/res the same diameter as your pipping however.

[Semtex]

are you going to do it yourself? alot of work if you dont have the right tools,gaskets or welder, besides if you take it to a shop they will take care of all that


as for sizing your looking for 2 1/8th i beleive is the next size up, if your really stumped goto your local parts/exhast shop grab a 2 1/2" pipe and see what goes over it and can slide into it snugly

best of luck

[Protoss]

well it depends on what you want to gain. i would _suggest_ that you not go smaller of any component than your piping diameter. Also, think if you got a 2 1/4" piping outer diameter, your in inner diameter is on average 2 1/8.

if you are going foir a 2 1/4 piping i would match your compnents with it. it maintaines flow velocity, and pulse. also if you want, lose the resinator if you dont mind a louder exaust. it will yield a slightly better flow.

[Marc93lx]

are you going to do it yourself? alot of work if you dont have the right tools,gaskets or welder, besides if you take it to a shop they will take care of all that
best of luck

No, Im going to have a shop do it. But I plan to buy everything except for the pipe elsewhere. (high flow cat, maybe a resonator)

also if you want, lose the resinator if you dont mind a louder exaust. it will yield a slightly better flow.

Actually, I already had the resonator removed and Im contemplating replacing it.

[limpgtx]

Why dont you get the pacesetter exhaust, it's a good price for a mandrel bent system. I would suggest getting your own muffler and putting a coat of spray paint over the piping. Or you could go under your car and look at all the bends and order some mandrel bent from www.jcwhitney.com and an exhaust shop can use that for the bends. You might wanna get some more air flowing in the engine before going 2 1/4 though. I'm not talking your basic intake and rx-7 air flow meter, more on the line of cams and ported intake mani. Just depends how far you wanna go with the car, and on the lines of looks or actual performance.

[Marc93lx]

Why dont you get the pacesetter exhaust, it's a good price for a mandrel bent system. I would suggest getting your own muffler and putting a coat of spray paint over the piping. Or you could go under your car and look at all the bends and order some mandrel bent from www.jcwhitney.com and an exhaust shop can use that for the bends. You might wanna get some more air flowing in the engine before going 2 1/4 though. I'm not talking your basic intake and rx-7 air flow meter, more on the line of cams and ported intake mani. Just depends how far you wanna go with the car, and on the lines of looks or actual performance.

I had thought about just getting the pacesetter system, but I don't know. Im still contemplating between 2" and 2 1/4" piping. I think the general consensus is that 2" is the best for the BP, so that may be what I will go for. New cams and porting are in my future plans, but not in my current budget.

[Protoss]

do you live near any snow. if so the pacesetter will corrode on you. if you are replacing your resenator, keep withthe pipe diameter. remember some thing measure inner piping diameter, some meause outter diameter. it might only be a 1/8" difference, make sure you see the part befoer you buy or at least ask a lot of questions.

better looking like a dumbass than being screwed and buying something twice.

[Marc93lx]

do you live near any snow. if so the pacesetter will corrode on you. if you are replacing your resenator, keep withthe pipe diameter. remember some thing measure inner piping diameter, some meause outter diameter. it might only be a 1/8" difference, make sure you see the part befoer you buy or at least ask a lot of questions.

better looking like a dumbass than being screwed and buying something twice.

We don't get much snow here (oklahoma), and when we do its usually gone in a day or two so thats not a big problem.
I will look around and see what I can find. Thanks.