Feasibility study: Quiet 3" Exhaust
Thread Starter
Ek Forever y0!
Joined: May 2005
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From: Beating people with a stick, GA
Okay, so for months now I've been scratching my head about this.
Doing an h2b swap in February hopefully, and my current plan for exhaust is as follows:
1) Logic Motorsports header
2) High Flow Cat (Size for inlet/outlet?)
3) 3" piping, either a kit or have my shop just bend one.
4) 70mm or 80mm Apexi WSII Universal muffler (70mm is ~2.75" and the 80mm is 3.14", I'm guessing the 80mm is better.)
Some sort of resonator
My goal here is to get a relatively quiet 3" exhaust, the Apexi universal is a straight-through design from what I understand. Just trying to gauge opinion on the potential for this to work.
I'm not expecting it to be remotely near stock, but as long as it's quieter under normal driving I'll be a happy camper. At the moment the only resonator I've seen any feedback on is a 14"x3" Vibrant Quiet resonator.
So far it looks like the exhaust (header back) is going to be a very expensive part of my build.
Thanks!
Doing an h2b swap in February hopefully, and my current plan for exhaust is as follows:
1) Logic Motorsports header
2) High Flow Cat (Size for inlet/outlet?)
3) 3" piping, either a kit or have my shop just bend one.
4) 70mm or 80mm Apexi WSII Universal muffler (70mm is ~2.75" and the 80mm is 3.14", I'm guessing the 80mm is better.)
Some sort of resonator
My goal here is to get a relatively quiet 3" exhaust, the Apexi universal is a straight-through design from what I understand. Just trying to gauge opinion on the potential for this to work.
I'm not expecting it to be remotely near stock, but as long as it's quieter under normal driving I'll be a happy camper. At the moment the only resonator I've seen any feedback on is a 14"x3" Vibrant Quiet resonator.
So far it looks like the exhaust (header back) is going to be a very expensive part of my build.
Thanks!
I have a full 3 inch mandrel bent exhaust on my all motor civic. I have a small tube tri-y, 3 inch piping, and just a 3"x16" long magnaflow straight through muffler out the back. It is actually pretty quiet! I can drive on the interstate at 4000 rpms and easily talk on my phone to someone without having any trouble hearing them. They can't even hear the car in the background when talking to me... I will try and find a video, but not sure if i have one.
You can make it fairly quiet but it won't be cheap. I'll be using about $250 in just resonators in the B pipe. The best muffler is a turbo but we don't use those words round these parts lol.
Im doing something similar for my H2B hatch
SSR Header
3" alu exhaust piping with a 3" vibrant alu resonator and a 3" vibrant alu race muffler
ill report back
SSR Header
3" alu exhaust piping with a 3" vibrant alu resonator and a 3" vibrant alu race muffler
ill report back
i have a bisi header and thermal exhaust...its not the loudness that bothers me..it has an annoying buzz ....im thinking of changing the muffler on mines..
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I have a full 3 inch mandrel bent exhaust on my all motor civic. I have a small tube tri-y, 3 inch piping, and just a 3"x16" long magnaflow straight through muffler out the back. It is actually pretty quiet! I can drive on the interstate at 4000 rpms and easily talk on my phone to someone without having any trouble hearing them. They can't even hear the car in the background when talking to me... I will try and find a video, but not sure if i have one.
My next plan is to add another 12" Vibrant resonator and switch to an oval muffler out the back, but this should serve as a warning that people aren't joking when they tell you a 3" exhaust is NOT quiet.
if you want the quietest exhaust. climb under the car with a measuring tape. find out what the biggest oval straight trough muffler is you can cram in there and make it work.
for quiet mufflers BIGGER is BETTER!!!
oh, and a turndown at the tip (diesel style) helps also
Thread Starter
Ek Forever y0!
Joined: May 2005
Posts: 16,712
Likes: 9
From: Beating people with a stick, GA
I assume you mean a turbocharger, not the turbo WSII muffler?
I've been told pretty mixed opinions on the feasibility of keeping a 3" exhaust quiet.
I'm mainly going to be using the car as a daily driver and for 6-10 autocross events per year. So if keeping it 2.5" keeps it that much quieter I'll just go with that. I know the h22 would stand to gain a lot of power with a 3" exhaust, but I'm pretty sure I'll be commuting to Atlanta this summer and fall before I can save up enough money to buy a TSX/TL for a commuter. (I don't finance anything)
I was at first thinking that the 2.5" might be a fine compromise as it might help keep the power at the low/mid range but I've seen plenty of dynos now that show h22s gaining HP and TQ at all points on the powerband with a 3" exhaust, so I figure even for autocross the 3" is superior for power in the low/mid range that is often associated with autocross driving.
I've been told pretty mixed opinions on the feasibility of keeping a 3" exhaust quiet.
I'm mainly going to be using the car as a daily driver and for 6-10 autocross events per year. So if keeping it 2.5" keeps it that much quieter I'll just go with that. I know the h22 would stand to gain a lot of power with a 3" exhaust, but I'm pretty sure I'll be commuting to Atlanta this summer and fall before I can save up enough money to buy a TSX/TL for a commuter. (I don't finance anything)
I was at first thinking that the 2.5" might be a fine compromise as it might help keep the power at the low/mid range but I've seen plenty of dynos now that show h22s gaining HP and TQ at all points on the powerband with a 3" exhaust, so I figure even for autocross the 3" is superior for power in the low/mid range that is often associated with autocross driving.
You can make the 3in quiet. You will need a resonator in the tunnel and the biggest muffler you can get in the back. I am getting this:
http://www.magnaflow.com/02product/s...e=main&id=9367
Skip the straight through and get something with the biggest volume you can find. Big mufflers allow room for the exhaust gases to expand and slow down. That is what you need to get the exhaust quiet. Use the resonators to tune out the drone. You may need one of these to get the drone down:
http://www.magnaflow.com/02product/s...e=main&id=9387
You may not have room in the tunnel for this.
http://www.magnaflow.com/02product/s...e=main&id=9367
Skip the straight through and get something with the biggest volume you can find. Big mufflers allow room for the exhaust gases to expand and slow down. That is what you need to get the exhaust quiet. Use the resonators to tune out the drone. You may need one of these to get the drone down:
http://www.magnaflow.com/02product/s...e=main&id=9387
You may not have room in the tunnel for this.
22" long muffler at the rear of a honda?? Just not a lot of room to work with back there. Tunnel resonators in a civic or integra shouldn't be more than 5" in OD or you will be ripping them off. 6" OD can fit in an accord or prelude.
Thread Starter
Ek Forever y0!
Joined: May 2005
Posts: 16,712
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From: Beating people with a stick, GA
So it looks like with a Catalytic converter and a long resonator I should be pretty reasonable.
For $300 I hope the Apexi universal is worth it. A vibrant is only $100, pretty tempting.
Edit: Found these: http://www.magnaflow.com/02product/s...e=main&id=9515
http://www.magnaflow.com/02product/s...e=main&id=9401
Here's a good price on the Vibrant Ultra Quiet resonator. http://www.aptuned.com/VIB-1142
For $300 I hope the Apexi universal is worth it. A vibrant is only $100, pretty tempting.
Edit: Found these: http://www.magnaflow.com/02product/s...e=main&id=9515
http://www.magnaflow.com/02product/s...e=main&id=9401
Here's a good price on the Vibrant Ultra Quiet resonator. http://www.aptuned.com/VIB-1142
I assume you mean a turbocharger, not the turbo WSII muffler?
I've been told pretty mixed opinions on the feasibility of keeping a 3" exhaust quiet.
I'm mainly going to be using the car as a daily driver and for 6-10 autocross events per year. So if keeping it 2.5" keeps it that much quieter I'll just go with that. I know the h22 would stand to gain a lot of power with a 3" exhaust, but I'm pretty sure I'll be commuting to Atlanta this summer and fall before I can save up enough money to buy a TSX/TL for a commuter. (I don't finance anything)
I was at first thinking that the 2.5" might be a fine compromise as it might help keep the power at the low/mid range but I've seen plenty of dynos now that show h22s gaining HP and TQ at all points on the powerband with a 3" exhaust, so I figure even for autocross the 3" is superior for power in the low/mid range that is often associated with autocross driving.
I've been told pretty mixed opinions on the feasibility of keeping a 3" exhaust quiet.
I'm mainly going to be using the car as a daily driver and for 6-10 autocross events per year. So if keeping it 2.5" keeps it that much quieter I'll just go with that. I know the h22 would stand to gain a lot of power with a 3" exhaust, but I'm pretty sure I'll be commuting to Atlanta this summer and fall before I can save up enough money to buy a TSX/TL for a commuter. (I don't finance anything)
I was at first thinking that the 2.5" might be a fine compromise as it might help keep the power at the low/mid range but I've seen plenty of dynos now that show h22s gaining HP and TQ at all points on the powerband with a 3" exhaust, so I figure even for autocross the 3" is superior for power in the low/mid range that is often associated with autocross driving.
For auto-x, you're only going to be in 2-3 gears anyway, in which a 3" exhaust is not going to help you in the powerband that you're looking for for that kind of racing.
I used a simple 2.5" with Resonator, CarSound High flow cat (2.5" collector Spoon Header) and a Greddy Evo II muffler. It made over 200whp and this is my wife slowing down at a shakedown of the brake system.
http://www.youtube.com/watch?v=gxwBqbvEscs
There's no need for 3" trying to believe it will make a big difference in the mid-range.
ive seen a couple video with vibrant resonators. quiet and UQ.
i like em. never in person heard one though.
id say use a cat, some UQ resonators and a muffler.
i have a couple things from vibrant in my exhaust and so far they all hold up well. planning to add a resonator or UQ one.
i like em. never in person heard one though.
id say use a cat, some UQ resonators and a muffler.
i have a couple things from vibrant in my exhaust and so far they all hold up well. planning to add a resonator or UQ one.
Thread Starter
Ek Forever y0!
Joined: May 2005
Posts: 16,712
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From: Beating people with a stick, GA
I used a simple 2.5" with Resonator, CarSound High flow cat (2.5" collector Spoon Header) and a Greddy Evo II muffler. It made over 200whp and this is my wife slowing down at a shakedown of the brake system.
http://www.youtube.com/watch?v=gxwBqbvEscs
There's no need for 3" trying to believe it will make a big difference in the mid-range.
Thanks Shodan

Indeed, I'll probably hardly get out of 2nd on most autocross courses. Maybe 3rd if they give us a large straightaway.
Any difference between a 2.5" carsound and any other brand? There are a few companies making 2.5" aftermarket cats. This one is $90 http://www.vrsexhaust.com/CATALYTICS/catalytics.html
That's about what I paid for my magnaflow "high flow cat." and I haven't had any problems with it. I didn't know it was high flow till my mechanic pointed it out.
I never was a vibrant muffler fan. And I've owned a couple. I'd say use all what you propose except use a universal world sport muffler instead of the vibrant
Thread Starter
Ek Forever y0!
Joined: May 2005
Posts: 16,712
Likes: 9
From: Beating people with a stick, GA
So I'll just have my shop run 2.5" piping from the Logic Header, some high flow cat, vibrant resonator, and the WSII universal.
Anything to know about Catalytic converters?
These seem like a steal at $90.
http://www.vrsexhaust.com/CATALYTICS/catalytics.html
Last edited by Libertariat; Jan 10, 2012 at 12:14 PM.
Any EF can handle that size muffler. Its positioned sideways.
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From: Woodbridge, NJ, Middlesex
nothing beats the loudness in my WRX, so not all turbo cars are quiet... I had an extra 3" Apex WSII muffler so will remove the apex N1 and try to fit the WS2
for all motor honda with 3", if you have $ the Mugen twin loop muffler or the HyTech twinloop def is the quietest hands down (even quieter than the WS2)...SMSP prolly has a twin loop as well.
I know this as a fact with a 13.5:1 compression street motor with no restriction and SMSP header with HyTech twinloop, it was slightly louder than a stock muffler and made as much power and a full blown "free flow" exhaust...my setup made 279whp on my b-series with this full exhaust so i know there was very limited restriction.
just dont buy the ebay junk twin loops, they rattle after a while I heard.
for all motor honda with 3", if you have $ the Mugen twin loop muffler or the HyTech twinloop def is the quietest hands down (even quieter than the WS2)...SMSP prolly has a twin loop as well.
I know this as a fact with a 13.5:1 compression street motor with no restriction and SMSP header with HyTech twinloop, it was slightly louder than a stock muffler and made as much power and a full blown "free flow" exhaust...my setup made 279whp on my b-series with this full exhaust so i know there was very limited restriction.
just dont buy the ebay junk twin loops, they rattle after a while I heard.
Thread Starter
Ek Forever y0!
Joined: May 2005
Posts: 16,712
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From: Beating people with a stick, GA
I'll certainly keep the twin loops in mind. Right now the plan is:
WSII muffler (60mm) or 70mm? 2.36" vs 2.75"
looking like a Vibrant 2.5" spun metal core cat
2.5" piping
14" vibrant ultra quiet resonator
Logic Motorsports Tri-y
WSII muffler (60mm) or 70mm? 2.36" vs 2.75"
looking like a Vibrant 2.5" spun metal core cat
2.5" piping
14" vibrant ultra quiet resonator
Logic Motorsports Tri-y




