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A combination of a resonator and a chamber muffler system my help or like HyTech does it a Twin loop muffler design. I would talk to HyTech, they know exactly what to do.
if you are sure about like orginal exhaust sound im going to change my exhaust.
 

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Discussion Starter · #42 · (Edited)
I don't have any expectations for stock like sound levels. If I can get 3-6dB less than a straight through 2.5" setup I'll be happy with that. I'd have certainly liked to have tried for a twin loop, but they only seem to go up to 2.5" in any reputable brand, so we'll see how the SW turbo muffler and a big glasspack as a resonator goes. 馃
 

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96 civic HX K24a
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I don't have any expectations for stock like sound levels. If I can get 3-6dB less than a straight through 2.5" setup I'll be happy with that. I'd have certainly liked to have tried for a twin loop, but they only seem to go up to 2.5" in any reputable brand, so we'll see how the SW turbo muffler and a big glasspack as a resonator goes. 馃
I鈥檓 sure paired with any decent header that will be a nice sounding setup which shouldn鈥檛 be too loud. Especially if your car still has the interior and deadening in it.
 

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Discussion Starter · #44 ·
I鈥檓 sure paired with any decent header that will be a nice sounding setup which shouldn鈥檛 be too loud. Especially if your car still has the interior and deadening in it.
Yeah, I've got a full interior and k-tuned 4-1 header. Let's hope it turns out well. 馃槑
 

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Discussion Starter · #48 ·
If all goes well it'll get a dyno tune on the existing exhaust this week, then put back on the dyno with the new exhaust and tuned further if needed. 馃should have comparison numbers from the same car on the same dyno on the same day either way.

103845
 

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96 civic HX K24a
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Here鈥檚 a short clip of my k24 with godsnow (ebay) 3鈥 piping, 3鈥 vibrant street power muffler and Rcrew header. When I took this it was right after welding and I hadn鈥檛 received my gaskets yet. Revs limited to around 3.5k rpm.

 

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Discussion Starter · #53 · (Edited)
I'm working on getting a chart with both together, ended up skipping the cat and glasspack in the end, and seem to have some other bottleneck someplace but the the 3" exhaust with the Dynomax Bullet + Stainless Works muffler picked up 3whp compared to the Yonaka 2.5" exhaust. I dunno if my stock RSX-S throttle, or the k-tuned header, is holding me back but going from a straight through 2.5" exhaust to a 3" exhaust with a turbo style chambered muffler quieted things down and yielded 3whp.

Not a cheap thing to measure 馃槶, in the end, but it is what it is.

104041


--Matt
 

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Damn. What鈥檚 up with the torque dip between 3800 and 5000? That鈥檚 looks to be about 20wtq there. Usually torque is pretty uniform through much of the powerband. Did the tuner explain that?

What header do you have... you mentioned in the very first post that it was a 4-1 header.

KBuilt, I like Vibrant products. That muffler you have there is awesome. Years ago I had a Vibrant 3鈥 street power on a fully 3鈥 exhaust with no converter and that thing was still pretty quiet (I also used a Vibrant Ultra Quiet resonator too). And that was also in a Del Sol (AKA the rattle can) which is not the quietest Honda in terms of NVH so that was impressive.
 

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Damn. What鈥檚 up with the torque dip between 3800 and 5000? That鈥檚 looks to be about 20wtq there. Usually torque is pretty uniform through much of the powerband. Did the tuner explain that?

What header do you have... you mentioned in the very first post that it was a 4-1 header.

KBuilt, I like Vibrant products. That muffler you have there is awesome. Years ago I had a Vibrant 3鈥 street power on a fully 3鈥 exhaust with no converter and that thing was still pretty quiet (I also used a Vibrant Ultra Quiet resonator too). And that was also in a Del Sol (AKA the rattle can) which is not the quietest Honda in terms of NVH so that was impressive.
It鈥檚 by far my favorite one, especially for k series on a full 3鈥. I鈥檓 actually very surprised how tame the car sounds and how quiet it is for having 3 inch piping and a straight through muffler. I鈥檝e always been a firm believer the best place to begin a great sounding exhaust (especially on Hondas) is with a nice quality header.
 

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Discussion Starter · #56 · (Edited)
Damn. What鈥檚 up with the torque dip between 3800 and 5000? That鈥檚 looks to be about 20wtq there. Usually torque is pretty uniform through much of the powerband. Did the tuner explain that?

What header do you have... you mentioned in the very first post that it was a 4-1 header.
It's one of these: KRH-41-500-4-1 K-Swap Race Header </br>Polished 304 Stainles

They did not explain it. Based on your response I may ask again, though. I recall seeing lots of dynos for these engines with a dip around there but, and hondata has some info explaining why, but I suppose that dip is a touch bigger than I'm accustomed to seeing. VTEC is engaging at 5k, where things pick back up again. Perhaps it could use to switch 100-200rpm earlier. 馃し鈥嶁檪锔

--Matt
 

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Discussion Starter · #57 · (Edited)
Heard back from the tuner. The answer comes down to...

This is 35 VTC tapering down until VTEC comes on at 5k. Dyno results vary by type of dyno, as well as scaling, and can't be compared directly with other brands/settings. They prefer to dial back scaling in their graphs (rather than using default), for the sake of accuracy over smooth lines, so things look like they do.

They tested with earlier VTEC engagement and it lost power, so this is where they landed. Mine looks more pronounced because the cam is making more power than a factory cam will in that area so I get a hump and then a drop where it would typically lay flatter.

--Matt
 

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Discussion Starter · #58 · (Edited)
I guess I should share pics. The pipe right after the header looks like it's taking some SERIOUS heat! I've not dealt with many of these cars before, but that's a crazy amount of blue for an exhaust that's only been together for about a week. In spite of it being 3" pipe, the fitment is a million times better than the Yonaka exhaust. 鈽
104058

Automotive lighting Automotive tire Motor vehicle Bumper Wood

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Don't get me wrong, it's not "quiet" like a factory exhaust by any stretch. It doesn't drone like the last setup, though, and is much quieter at normal cruising RPMs. Once VTEC kicks in the car is pretty rowdy, but I hear the HR intake more than I hear the exhaust there FWIW.
 

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Discussion Starter · #59 ·
Oh, also, here's the comparison dyno between the 2.5" and 3" exhaust. Less dip with 2.5", and a bit more power down low, but 3" makes a bit more power from ~6k on. So, in this car's case at least, a 2.5" straight through exhaust makes a touch less peak power and torque than a 3" exhaust with a chambered muffler imposing a bit more restriction.

104061


FWIW, at the end of the day, the dip isn't noticeable at all on the road and I'm generally past 5k when hammering it anyways.

--Matt
 

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I guess I should share pics. The pipe right after the header looks like it's taking some SERIOUS heat! I've not dealt with many of these cars before, but that's a crazy amount of blue for an exhaust that's only been together for about a week. In spite of it being 3" pipe, the fitment is a million times better than the Yonaka exhaust. 鈽
View attachment 104058
View attachment 104057
View attachment 104060

Don't get me wrong, it's not "quiet" like a factory exhaust by any stretch. It doesn't drone like the last setup, though, and is much quieter at normal cruising RPMs. Once VTEC kicks in the car is pretty rowdy, but I hear the HR intake more than I hear the exhaust there FWIW.
The exhaust came out very nice, I also have the hybrid racing intake and noticed it makes a very pronounced sound as soon as the TB starts to open. I dig it lol. Iat stay very close to ambient temps when moving as well.
 
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