Resonator on a 3" exhaust?

[Raf99]

I have a 3" exhaust now with a "quiet" flow master muffler. I say quiet because that is what it is advertised as. To say the least the car is not quiet. Drive around with the back windows down, nope. Would my grandma want to be in this car, nope. Turn the music up to drown out the exhaust, yep. Feel bad when you need to drive up hill in a rural neighborhood......... , you get the point.

Does the exhaust sound good, sounds great!

But the respectful guy I am and not wanting to be a sponsor of Advil, I wanted to quiet it down a little. Will a resonator help?

I am getting mixed answers from folks. Some say it gets rid of the "raspy", but i don't have "raspy", i just have "too loud". All the youtube videos I watched seem to make the sound "more manly" in my opinion. They all sounded better. But none talked about highway drone, etc.

Your thoughts?

[cp[mike]]

in for an answer to this important question.

[sonikaccord]

But the respectful guy I am and not wanting to be a sponsor of Advil, I wanted to quiet it down a little. Will a resonator help?

From personal experience when I went from one resonator to two resonators, the answer is kind of. It more so dulled the sound than made it quieter. That's the best way I can put it.

I think a true muffler is the best way to get a more "quiet" exhaust.

Think about what a resonator does...it well...resonates. It's going to cancel out some frequencies based on its construction while letting other, typically lower frequencies, through.

A muffler...muffles?...the sound. It restricts and slows down the exhaust, causing it to lose acoustic energy, and hence a quieter sound.

IDK...it sounded good in my head.

[F22Chris]

Anti-drone pipes maybe? They bounce back the same frequency as the exhaust puts out to rid drone.

https://www.performancetrucks.net/fo...-drone-489463/

[deevergote]

I ran the longest resonators I could fit on my 2.5" exhaust. It helped a great deal. It turned my sound from obnoxiously loud to somewhat reasonable. It was still loud, and long trips would still make your ears ring a bit... but it was much MUCH better than it was before the resonators.

Honestly, resonators are basically just elongated inline mufflers.
Here's a generic resonator half-cut. Just a perforated pipe wrapped in fiberglass (or other sound deadening material...). Generally straight-through, so little exhaust velocity is lost, but it does make a noticeable difference.

[Corweena]

Vibrant also makes their Ultra Quiet Resonators, which are almost more like mini mufflers. They work pretty well. Only downside is they are a bit bulkier, and I'm not sure if the CB has enough room in the midpipe section under the chassis to mount them with enough ground clearance.

Regardless, a 3" exhaust is gonna be loud. Even with a chambered muffler like a WS2, it's significantly louder than your typical 2.25 or 2.5 setup.

[illinois_erik]

put another muffler inline midstream, itll be that much better than a resonator; itll help, but not how youre wanting i think.


https://vibrantperformance.com/catal...products_id=47
meh they consider this a resonator still but you get the jist

https://www.maperformance.com/produc...ant=5297253955

"Vibrant's Ultra Quiet Resonator utilizes a larger sound absorption chamber for better sound suppression than typical bottle style resonators. Feature Vibrant's "True Straight Through" perforated core, surrounded by our premium multi-layer sound absorpt"


"low profile muffler"

[GhostAccord]

Have a 2.5" header back system on my V6 Grand Am.

Cat and resonator delete with a single in dual out Flowmaster 80 series Crossflow muffler. Man did it ever sound great.....for about a week!

Added a 28" Thrush Glass pack muffler (resonator) to my mid pipe and love it. It got rid of the annoyingly loud idle and cruising drone. But when I want to get on the throttle it comes to life. It is a straight through design so there is no restriction to flow.

[Raf99]

Alright, thanks everyone. I'm going to get it done. By the sounds of it it will do something. Either quieter, maybe duller, but when you're talking about a 3" exhaust with a already deep idle tone that is ok. If the tone at highway speeds is quieter or duller I'm ok with that too. But it sounds like all cars I seen that did WOT sounded a lot better! Deeper sound. If I remember I'll take a before and after vid.

[Raf99]

OK, it has been done. I went with the Vibrant's Ultra Quiet Resonator.



Little worried about clearance issues, but I may be ok. We'll see.


Conclusion:
- Another muffler add is a good idea but adds restriction. I'd rather have as less restriction as possible. If you were implying to add dual exhausts but no in serial, then ya i agree! I wish this car sounded like a beefy TSX or V6.

- Did it help? ahhhhh...... not really but a little. As Corweena said, 'no matter what a 3" exhaust is going to be loud'.

- Where did it help? "At high rpm. Before the resonator when sitting still and reving to 6K the sound grew and grew until it was this raspy lawnmower-ish, high pitched sound. With this it sounds muffled like a subaru at the high end. But in extreme downshifting you don't notice it at all. So hard to explain.

....... it didn't change the loudness it just changed the pitch at certain rpms with some dulling or deepening. I kind of have before and after.

Before is in a garage.


AFter is outside the garage


Yep, kind of like someone ran the sound through a mixing board and took out all the highs and cleaned up the lows. I think only I can tell the difference

Edit*: OH, big thanks to Raven Autosports for all the help!

[Rilas]

It sounds a lot more fluid now. Just a rising tone instead of changing the tone and rasping out. It does sound quite a bit better from what I can hear in the videos at least. Hopefully it makes driving Sally a better experience.

Adding a second resonator might get you to the sound you are looking for. I was alright with one resonator but much happier, after I added the second one behind the down pipe of the header. It cleaned up the sound and toned it down quite a bit. Also it was interesting to note that even the Yonaka exhaust that H311RA151N bought has 2 resonators inline, just some food for thought.

[GhostAccord]

That can is way to small to do anything at all for reducing decibels. I had to go with a 28" long, 4" diameter resonator in order to quite mine down.

Is your muffler tip 3" or larger? You could try reducing the tip to 2.5" or do a dual 2"/1.75". I remember when a buddy of mine thought it would be cool to put a 4" dia. boom tip on his Ram. That thing was so F#@king annoying. He quickly switched it to a dual tip and it was a lot better.

[Raf99]

I did notice tonight cruising down a back road doing 80kph (50mph) in 5th that the drone sound was not noticeable. Like I forgot about it and at one point realized that I didn't have this annoying drone like I use to. I would definitely add a 2nd, but think I'll stick with this for now.

[19dabeast85]

I'm back from the dead (haven't had a cb7 for 5 years lol) to check out the site and see what's up. Glad to see it's still decently active!

So resonators:

They aren't necessarily going to lower decibels, at least not much, but they will shift the rpm(s) at which highway drone and raspiness occurs. You can effectively use a specific length of resonator to move your worst drone to a non-cruising rpm.

Resonators change the rpm of drone and deepen the raspiness......a large enough resonator will eliminate all raspiness. My cb7 (stock block, h23IM, true CAI, bisi header, 2.5" custom mandrel back) had a 14" resonator where the cat was that immediately dumped into a 28" resonator before the bend towards the passenger side. It then dumped into an aero chamber high flow muffler. I ha 42" of resonator and zero raspiness but it was still decently loud. Droned like a mofo at 75-80mph, quiet as a whistle above 90mph.

You see my point.....use resonators to eliminate raspiness and to custom tune where your droning occurs. There's science to figure it out but I'm not that smart. I did a lot of research at the time and swung the bat and hit it pretty close to where I wanted the sound to be.

[illinois_erik]

wow that can was small