Hey everyone, after searching and reading for a while I've got a couple questions and ideas to throw out, and I wanted some opinions. I'm looking at getting my wife some kind of exhaust for her '02 Sunfire for Christmas (yes, I can get away with that, she'll love it...ahh women who love cars ). I know there's several bolt-on exhausts already made, but I'm also wondering about buying muffler(s) and a resonator and going custom. Here's the systems I'm considering:

1) RKSport single or dual
2) Custom single with a resonator - 2.5" piping
3) Custom dual with a resonator - 2.5" piping to Y, then 1.75" piping after it

I understand that generally a dual exhaust doesn't serve a real purpose on a 4 cylinder, but with the bumper of an '02 Sunfire it'd look great. Plus, by reducing the size of the piping after the Y, there shouldn't be any real loss of power, right? I was planning that the resonator be put as close as possible to the cat, and then have the Y put right after it. If need be then the two pipes could run in parallel until they reached the axle and then each would go to its own muffler.

Cost is a bit of an issue - I can't afford to go over the price of the dual RKSport (it's a little bit more than I'd like to spend as it is). Currently the only other mod the car has (besides 17" wheels) is an ebay warm air intake. She loves the sound it gives the engine, so we still want to hear that (and we don't want it to get too loud anyways, if possible). Eventually the car will get at least headers...maybe turbo down the road. I know generally (at least on an Eclipse V6, which is what I drive) people go to a 3" exhaust with turbo. Would a 2.5" exhaust (single or dual) be big enough for a turbo on a 4 cylinder?

i would say that 2.5" would be perfect. but in any case i would install a resonator. just to throw it out there, maybe check out a camaro style exhaust, single inlet muffler and dual outlet, and with the cutouts of the sunfire bumper i think it would be hot! for an example look here near the bottom of the thread. Clicky


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rhodaz24 wrote:i would say that 2.5" would be perfect. but in any case i would install a resonator. just to throw it out there, maybe check out a camaro style exhaust, single inlet muffler and dual outlet, and with the cutouts of the sunfire bumper i think it would be hot! for an example look here near the bottom of the thread. Clicky

Yeah I'd seen the camaro style one in another thread...it looks good on a cavalier, I'm not sure what I'd think of it on a sunfire though. But the thing I'd read about those single inlet/dual outlet exhausts was that it would typically just suck air in through the passenger's side tip, rather than sending exhaust out. I figured with the split further up and two mufflers, the actual exhaust stream would be divided between the two...I dunno. If it weren't for the passenger's side cutout in the bumper, I would have never suggested the dual to her and I don't think either of us would have really thought about it. I never considered it on my Eclipse because not only does it not make a difference performance-wise, the cutout isn't there either. Why did GM put the cutout on the Sunfire if they weren't gonna have a dual exhaust anyways?

Your exhaust can only flow as much gas as the smallest diameter pipe you have. So if you go turbo, the 1.75" pipe after the Y is a bad idea. 2.5" should be just fine as rhodaz24 said. But 2.5" on a non-boosted engine isn't necessary and might be a bad idea (simply due to the fact that you need some back pressure or you'll lose some low-end power). I always say that an exhaust system decision should be done after deciding on a boost project because you never know what kind of system you'll want/need and you wouldn't want to wind up paying for new piping to upgrade from, say, 1.75".

If you want to hear the engine, I would definitely suggest a resonator. The larger the resonator, the quieter and smoother the exhaust note will turn out. In my opinion I'd look for something at least 25"-28" long. As for the header, we only have one so its not headers. Keep in mind that an aftermarket header is pointless if you decide to go turbo. You'll need a custom exhaust manifold made and a header will not be necessary.

I hope this helps, bro, and good luck with your project/gift!



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personally i think the duals would look way better on a sunfire than a cavalier....seeing that the fires have the dual cutouts already from the factory. for the camaro style setup, u will not see the muffler, only the tips, and i think that would look really clean on a fire.


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Filip (The Polish Kid) wrote:If you want to hear the engine, I would definitely suggest a resonator. The larger the resonator, the quieter and smoother the exhaust note will turn out. In my opinion I'd look for something at least 25"-28" long. As for the header, we only have one so its not headers. Keep in mind that an aftermarket header is pointless if you decide to go turbo. You'll need a custom exhaust manifold made and a header will not be necessary.

I hope this helps, bro, and good luck with your project/gift!

D'oh - yeah, I'm used to thinking V6 terms. Header it is.

And yes, I'm/we are aware of the turbo manifold situation. The point about the split to 1.75" piping being the most restrictive part of the exhaust is well taken - I was thinking by splitting it and keeping the overall cross-sectional area the same (the area of a circle with diameter 2.5" is about the same as the area of two circles with diameters 1.75" combined). But regardless, it's not gonna be a perfect split and yeah, that would be the most restrictive point in the exhaust. 2.5" single catback is sounding like the way to go - to avoid having to put a new exhaust on if turbo becomes a possibility. Aren't a decent amount of people using a 2.5" exhaust on J-bodies? Here again, my experience comes from a different car, but people with 4 cylinder Eclipses quite often use a 2.5" catback with no ill affects.

rhodaz24 wrote:personally i think the duals would look way better on a sunfire than a cavalier....seeing that the fires have the dual cutouts already from the factory. for the camaro style setup, u will not see the muffler, only the tips, and i think that would look really clean on a fire.

true, but the camaro style ones are rectangular, and the cutouts are round...I dunno, two round/oval tips would probably look the best IMO

Single cat-back would be fine, there is no real performance gain with duals on our cars. I bought a dual cat-back for my 03 Cavi because I thought it flowed well with the rear end of the car.

2.5" is about the standard that I've seen around here so you should be fine. And if you're getting a header and cat-back..just get a high-flow cat, too ( ).



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Ok, so 2.5" should be no real problem then. High flow cat is planned down the line - at this point just going with the catback section. Any specific mufflers that anyone would suggest? I'd prefer a name brand one (Magnaflow, Borla, Flowmaster, etc.), doesn't have to be the most expensive one out there. Ideally I would think a 2.5" inlet would be best - however Magnaflow makes most of theirs either 2.25" or 3" from what I've seen. I'm figuring the best idea would be to go with a 3" inlet and have the exhaust place flare the end of the axle section out to 3".

Anyone have any opinions on these?
Flowmaster 60 series

You can't go wrong with either Magnaflow or Borla. You can pick up a universal stainless-steel muffler from Magnaflow with 2.5" openings and buy some tips to weld on. I know a few people who have done this and are quite pleased. You can definitely avoid flaring the pipes by picking up the universal muffler that I just mentioned.

As for Flowmaster, I've never had much experience with that company but I hear mixed reviews. Do some searches in the performance forum and see what you can find.



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