Custom exhaust piping with stock muffler?

[yomuppet]

I know a lot of people upgrade their stock piping (mine is 2.25") to 2.5" when they upgrade to an aftermarket catback exhaust, but my question, is if I got custom 2.5" exhaust piping but kept my stock muffler, would I see the same increase in flow? Thanks

 

[edhgreatone]

good question i want to know this too

 

[yomuppet]

Doh, and I was hoping I had an answer already, haha 8)

 

[ImportRacerFF]

your muffler was built to be exact with the current piping, increasing the flow to the muffler will cause a "backup" of exhuast. If you replace the piping get a muffler that is a more straight less restrictive design.

 

[child_racer]

you wont perform as well as if you had a free flowing muffler as importracerFF stated........ my friend ran his 95 VX hatch with a H22A swap with the custom piping and stock muffler and hit a 14.2 , the next week we bolted on a axle back to add to his 2.5" piping and he ran a 13.5 It made a huge difference with that motor.....im sure the differences in power would vary to each application but i just posted that as a true example

 

[ImportRacerFF]

lol .7 off an exhaust? (.25 more flow) that motor had to be really restricted and if that is so he should see bout the apex 3" downpipe and exhuast (jdm). second this is a stock civic, 2.25 is more then enough flow, all thats restricting the exhaust is the muffler, cat, exhaust manifold. Even b16's can run on 2.25 exhausts without much holdback. Only when you start adding in real modifications (i.e. more then an intake) do you need a more open exhaust system. 2.25 is actully a good size to begin with because it keeps the velocity up and if added a muffler with a outlet of 2.25 or greater it would help more then opening the piping while his stock muffler is an outlet of much smaller then 2.25.

 

[yomuppet]

lol .7 off an exhaust? (.25 more flow) that motor had to be really restricted and if that is so he should see bout the apex 3" downpipe and exhuast (jdm). second this is a stock civic, 2.25 is more then enough flow, all thats restricting the exhaust is the muffler, cat, exhaust manifold. Even b16's can run on 2.25 exhausts without much holdback. Only when you start adding in real modifications (i.e. more then an intake) do you need a more open exhaust system. 2.25 is actully a good size to begin with because it keeps the velocity up and if added a muffler with a outlet of 2.25 or greater it would help more then opening the piping while his stock muffler is an outlet of much smaller then 2.25.

Well I'm asking about an Si (b16a2), sorry, I should have specified.

 

[baby99si]

yea it will hold you back but its cool looking i think seeing a stock exhaust on a fast car,but if you plan on doing stuff to your car it will hold you back probably not very much though.

 

[Sound Streamin']

Your goign to have massive back pressure, and in the end it will be a waste. Replace the muffler with the piping. You'd be stupid not to.

 

[yomuppet]

Your goign to have massive back pressure, and in the end it will be a waste. Replace the muffler with the piping. You'd be stupid not to.

Ok... well that's what I'm asking to find out - if I want a muffler that looks/sounds as close to stock as possible (quiet/inconspicuous) what's a good one to look into? The Greddy EVO still has the huge can on the back, and the Mugen Twinloop has the can and is pretty expensive, so alternatives are appreciated. Thanks.

 

[baby99si]

magnaflow looks stock

 

[yomuppet]

magnaflow looks stock

How does it sound? How much does it cost?

 

[baby99si]

its quite to but i have no idea how much it cost.

 

[child_racer]

a good quiet exhaust with good flow would be the Apex'i world sport or the GReddy SpII. each one runs about 400-450 on average. it holds a pretty good "sleeper" look while still performing and would be great for a Si.

 

[yomuppet]

a good quiet exhaust with good flow would be the Apex'i world sport or the GReddy SpII. each one runs about 400-450 on average. it holds a pretty good "sleeper" look while still performing and would be great for a Si.

Thanks for the tips. Where's the cheapest place to get an exhaust from and installed? I'm sure shipping on those babies is a b***h