What's up guys? I got a question for ya'll. I'm doing my exhaust here really soon and was wondering what size resonator should I use? I'm gonna run 2.25" piping and a magnaflow muffler, but my problem is I don't want the resonator to be to short to where it's still raspy, and I don't want it to be too long as to where it's too quite. I was thinking of running a 16'' vibrant resonator. What's ya'lls opinion?

A long resonator won't necessarily get rid of the rasp, but bigger is usually better in that regard. The best thing I can recommend is sticking with the stock exhaust manifold/dp to start with. Using a catalytic converter vs. a test pipe, etc. also will help.

My trd manifold makes the exhaust raspy as **** in the middle of the rpm range. I've used it with an hks sport cbe, stock cbe (both have large resonators), and a custom 2.25" cbe with magnaflow muffler (no resonator). A cc helped a little, but it mainly just muffled the sound rather than getting completely rid of the rasp. When I had the stock exhaust manifold it wasn't raspy at all, even with the custom cbe that didn't have a resonator.

I was gonna get rid of my cat anyway since my county doesn't have emissions, and I'm also gonna use my stock manifold. so how big of a resonator should I get then? What does the length of the resonator determine anyway if it doesn't do anything for the rasp?

Keep the cat.
It's a resonator that makes your cars farts smell pretty. Can't beat that.
If you still need more then you could consider adding another resonator. The resonator should help soften the sound a bit but it would take a ton of resonator to make it considerably more quiet. I hope you plan on running a muffler too because a resonator alone will not do much.

Without a cat the exhaust generally sounds more tinny and hollow, and perhaps more raspy in certain cases, but it rips in the upper rev range .

A resonator is supposed to help lower the sound dB. In theory a larger one will work better. However, not all exhaust components are created equal. Plus there are other variables as well that affect the exhaust note. I don't have a lot of experience with off-the-shelf resonators because I've never had a custom exhaust built. I can't make a specific recommendation.

yoshimitsuspeed wrote:Keep the cat.
It's a resonator that makes your cars farts smell pretty. Can't beat that.
If you still need more then you could consider adding another resonator. The resonator should help soften the sound a bit but it would take a ton of resonator to make it considerably more quiet. I hope you plan on running a muffler too because a resonator alone will not do much.

I wanna get rid of the cat so I can get more power and I'm running a muffler yes.

[quote="Deuce Cam"]Without a cat the exhaust generally sounds more tinny and hollow, and perhaps more raspy in certain cases, but it rips in the upper rev range .

A resonator is supposed to help lower the sound dB. In theory a larger one will work better. However, not all exhaust components are created equal. Plus there are other variables as well that affect the exhaust note. I don't have a lot of experience with off-the-shelf resonators because I've never had a custom exhaust built. I can't make a specific recommendation.[/quote

so what would you say a 3'' or 4'' inside and 18'' length? and what makes the raspiness?

I would keep a cat, highflow if that's what you want and to me a 16" resonator would be sufficient for your purpose, but it all goes by opinion in the end and no promises can be made as to if it will be your taste. Quiet and loud have different definitions that vary between people. Best bet when you want to find out how an exhaust will sound is to listen to some setups, find the ones you like and mimic that setup or trial and error and just keep trying till you are satisfied lol

DerekGreeson wrote:

yoshimitsuspeed wrote:Keep the cat.
It's a resonator that makes your cars farts smell pretty. Can't beat that.
If you still need more then you could consider adding another resonator. The resonator should help soften the sound a bit but it would take a ton of resonator to make it considerably more quiet. I hope you plan on running a muffler too because a resonator alone will not do much.

I wanna get rid of the cat so I can get more power and I'm running a muffler yes.

Cat's have been proven to loose only a few HP on 500+ Hp motors. On a sub 150 hp 4AGE the difference in power probably wouldn't be noticed on a dyno.

rumsawatti wrote:I would keep a cat, highflow if that's what you want and to me a 16" resonator would be sufficient for your purpose, but it all goes by opinion in the end and no promises can be made as to if it will be your taste. Quiet and loud have different definitions that vary between people. Best bet when you want to find out how an exhaust will sound is to listen to some setups, find the ones you like and mimic that setup or trial and error and just keep trying till you are satisfied lol

I just don't want that rice burner sound or atleast not that much of a rice burner sound. I just want it to have a lil more tone than it to be all rasp.

DerekGreeson wrote:

rumsawatti wrote:I would keep a cat, highflow if that's what you want and to me a 16" resonator would be sufficient for your purpose, but it all goes by opinion in the end and no promises can be made as to if it will be your taste. Quiet and loud have different definitions that vary between people. Best bet when you want to find out how an exhaust will sound is to listen to some setups, find the ones you like and mimic that setup or trial and error and just keep trying till you are satisfied lol

I just don't want that rice burner sound or atleast not that much of a rice burner sound. I just want it to have a lil more tone than it to be all rasp.

Throw on a 2 in or 2.5 in Hooker aero chamber. Very deep and throaty till about 4500. After that it cracks but in a good way. Plus that's just the 4A, I haven't seen a muffler that can prevent that.
The muffler will play a much larger role in how the motor sounds. The resonator will just have a small influence on it. As people have already said the effect that it has will depend on the brand, materials, packing vs hollow and other things.

yoshimitsuspeed wrote:

DerekGreeson wrote:

rumsawatti wrote:I would keep a cat, highflow if that's what you want and to me a 16" resonator would be sufficient for your purpose, but it all goes by opinion in the end and no promises can be made as to if it will be your taste. Quiet and loud have different definitions that vary between people. Best bet when you want to find out how an exhaust will sound is to listen to some setups, find the ones you like and mimic that setup or trial and error and just keep trying till you are satisfied lol

I just don't want that rice burner sound or atleast not that much of a rice burner sound. I just want it to have a lil more tone than it to be all rasp.

Throw on a 2 in or 2.5 in Hooker aero chamber. Very deep and throaty till about 4500. After that it cracks but in a good way. Plus that's just the 4A, I haven't seen a muffler that can prevent that.
The muffler will play a much larger role in how the motor sounds. The resonator will just have a small influence on it. As people have already said the effect that it has will depend on the brand, materials, packing vs hollow and other things.

yeah I guess I'll just have to do it as I go. Trial and error you know but thanks for the advice. I got a little more knowledge about it now.

What this thread needs is more pics.....


Typical resonator... straight thru with perforated tube and some packing around.


Typical high performance or "sports" muffler... straight thru with perforated tube,
more internal volume and a bit more packing around.


Typical muffler that actually quietens down your exhaust... triple pass, offset connections
with combination of perforated tube, expansion chambers and packing.

The original factory AE86 exhaust on my car had a small resonator/muffler under the
floor, and a triple pass muffler at the rear. The muffler was tuned to attenuate the
wicked raspy 4AGE note that occurs around 4200rpm, and it did a great job of keeping
the car quiet. I never found another muffler that worked as well as the factory one.

Straight thru resonators or mufflers are not very effective at reducing exhaust noise,
so you need a lot of them to get a quiet exhaust. Triple pass mufflers do a good job,
and if you get a performance design, you can achieve a "sporty" sound without being
overly loud. One 18" resonator plus a quality muffler will keep most people happy

Cheers... jondee86

jondee86 wrote:What this thread needs is more pics.....


Typical resonator... straight thru with perforated tube and some packing around.


Typical high performance or "sports" muffler... straight thru with perforated tube,
more internal volume and a bit more packing around.


Typical muffler that actually quietens down your exhaust... triple pass, offset connections
with combination of perforated tube, expansion chambers and packing.

The original factory AE86 exhaust on my car had a small resonator/muffler under the
floor, and a triple pass muffler at the rear. The muffler was tuned to attenuate the
wicked raspy 4AGE note that occurs around 4200rpm, and it did a great job of keeping
the car quiet. I never found another muffler that worked as well as the factory one.

Straight thru resonators or mufflers are not very effective at reducing exhaust noise,
so you need a lot of them to get a quiet exhaust. Triple pass mufflers do a good job,
and if you get a performance design, you can achieve a "sporty" sound without being
overly loud. One 18" resonator plus a quality muffler will keep most people happy

Cheers... jondee86

So pretty much your saying what'll help the best is if I get a 3 chamber muffler and an 18" resonator?

DerekGreeson wrote:So pretty much your saying what'll help the best is if I get a 3 chamber muffler
and an 18" resonator?

Resonator length is not critical... 16", 18", 24" whatever you can fit in the space
you have available. If you want the "fart cannon" sound use a straight thru muffler,
and change it later when you get sick of listening to the drone But for a quietish
muffler that won't annoy your neighbours, use some kind of triple pass muffler...
basically one that you can't poke a stick in one end and have it come out the other.

There are many different variations ranging from cheap no-name types made from
aluminised steel, up to high quality shiney stainless models. The best way to figure
out what you want is listen to the muffler on a car. If that is not possible, try and
find a review on a car magazine site.

Here is one set of results (from Australia) to give you an idea of how different
designs/brands compare... http://www.autospeed.com/cms/A_0383/article.html

Hope that helps

Cheers... jondee86

A multi chamber muffler will generally be the quietest but that doesn't mean that any straight through muffler is going to sound like a fart cannon.

Personally I avoid packed mufflers and resonators. 1. because I hate fiberglass in any situation. 2. because the packing breaks down changing the sound characteristics and muffling ability over time.

The aerochamber is more or less a straight through design but instead of using packing or having one big chamber it uses advanced port design and helmholts resonator technology to quiet the exhaust.



I have installed three of these. One 3" on my MR2. I ran it NA without a cat for a short period while I was building my turbo setup. It was definitely too loud by my standards and I don't mind a loud car. Next I added a turbo and a cat. Now it's loud but only bothers me in the least after about 2 hours on the road. This was also piped int the most direct route from engine to bumper so only about 6 feet of exhaust total. Length makes a big difference.
I installed 2.5 Aerochambers on my 2.5 RS along with a big resonator and also one on my moms V6 Chevy pickup with stock exhaust up to the muffler and 2.5" piping back.
All three cars sound incredibly deep. When the MR2 is lding in the morning you can feel it inside the house more than hear it. The Subie and pickup are a good bit quieter but still very deep. The subie is completely stripped inside and in the trunk including no back seats, carpet or sound deadening. It's a little loud but my GF and I survived a 2 hour road trip both ways without too much trouble.
The pickup is the quietest and probably due to the length of the exhaust. It is louder and deeper than stock but not by a whole lot.
If you want near stock sound this setup probably isn't for you. With a cat and a good resonator it might get close. If you don't mind a little louder than stock and appreciate a nice deep rumbling tone then this can is awesome.
Unfortunately I don't think they have a 2.25" option which would be perfect for most 4As but if you have less than 150 HP a 2" should be a good bit quieter and still flow plenty.