Suggestions for a "Performance" muffler that isn't too loud

Dobalovr

Being on the Cbody diet SUCKS!
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I am looking for suggestions for my 79 300 exhaust system to reduce the sound and vibration my current "Flow Through" system is causing. As many of you know my wife suffers from a debiltating nerve injury to her leg that reacts terribly to loud noises or vibration which has prevented her from going for a ride with me. She can tell when a train is 10 miles away just from the vibrations in our house. I do want something that will sing the song of our people when I step on it but is quiet at idle and under highway cruise. No drone etc. Flowmasters? Magnaflow? What have you used that didn't shake the windows but sounds good under full throttle?
 
I went to 1968 Cadillac mufflers on my '70 300. Walker #21856. I had the Turbo mufflers that came with the TTI system and the Caddy mufflers are much better. Still has a nice rumble, but no drone.

Another thought is to use cheap glass packs as resonators. I've done that with good results.
 
Drone is, basically, the sound bouncing around in the pipes. Performance mufflers don't do much to help curb this. Most big cars and A LOT of today's full size trucks have resonators somewhere in the system, generally in the longest section of pipe. I sell exhaust for a living, so this kind of question comes up almost daily. Flowmaster's chambered mufflers{unless you opt for the 50, 70, or 80 series} will drive your wife crazy. Magnaflow is a different type of muffler it's got a perforated tube surrounded by fiberglass. This design is quite a bit tamer, so to speak, size for size with Flowmaster. The larger the case, the quieter it will be. Most mufflers get larger in each direction the longer it gets. So, say you want a 22" long case, well then the oval will most likely be a 5x9 or larger oval. Which probably won't fit under your car. I can't speak to how your current mufflers are configured, like a center inlet\offset outlet or the oval and length dimensions. Get these measurements and visit Flowmaster's website. They have a "find it by dimension" page. Start there, then see what others offer too. I will end with this, my 75 Royal has a 400 and a single exhaust. The previous owner had the exhaust replaced from the Y pipe back, with a 14" Turbo muffler. At speed you can only hear a hum. At idle, it sounds great. I'm sorry for the lengthy reply, but it sounds like your choice is really important in a very personal way. But, please keep in mind once a muffler is installed and used it's yours. Choose carefully. Good luck.
 
Are you just looking for a single? If so, go as long as you can find/fit. I found the thrush mufflers a nice balance, perhaps a touch loud for what you are looking for. Their chambers have perforated plates which are free flowing but really mellow it down and produce no drone. They're just thin stamped (cheap) mufflers so one backfire and they're toast.

After blowing out one twenty year old set, then another brand new set, I bought heavy welded "Jones" mufflers. I hate them. The drone is terrible. Flow masters and magnaflow usually incorporate a similar offset tube and solid plate chamber design. I'm not sure that's the direction you want to go.
 
Are you just looking for a single? If so, go as long as you can find/fit. I found the thrush mufflers a nice balance, perhaps a touch loud for what you are looking for. Their chambers have perforated plates which are free flowing but really mellow it down and produce no drone. They're just thin stamped (cheap) mufflers so one backfire and they're toast.

After blowing out one twenty year old set, then another brand new set, I bought heavy welded "Jones" mufflers. I hate them. The drone is terrible. Flow masters and magnaflow usually incorporate a similar offset tube and solid plate chamber design. I'm not sure that's the direction you want to go.
Good intel Grant thanks! It's for the 79 300 with dual exhaust. It has Flowmaster 40's on it now I think but it sounds like it is straight piped. I am thinking of the magnaflow street series version 19303 as stated above. I like @Big_John 's idea as well so I will have to check dimensions.
 
In the 1980s, I was running a Test Tube (long term test) on my '77Camaro with the factory Z/28 cat back exhaust. It was louder than I wanted, so i measured and an aftermarket "fit kit" plus a '70 E-body resonator were the trick, bolt-on no cutting. When looking at the resonator when I got it, it was just a can with a perforated straight-thru pipe in the middle. I was curious, but put it on. I was surprised at how quiet things got. Perhaps something similar with the Cordoba 300 might work?

IF the system under the car has not been hacked too much, Walker might still have the same OEM-spec muffler and alternatives in their catalog. Including the "size specs" in the back of their catalog.

CBODY67
 
My free advice so take it for what it's worth;

Do not run a chambered muffler. I have run the long case Dynomax Super Turbo with good results. May need resonators to cure drone at cruise rpm depending on your rear gear ratio.The longer the case the quieter and less drone.

I have magnaflow on my 454 truck and Borla Pro xs on my 440 Duster. The Borla is really tame until you get on it. The Dynomax Ultra flow or the pypes race pro would be good choices also.

I am getting ready to throw the single flowmaster exhaust on my Newport in the trash and will be going with the Ultra Flow most likely as it comes in a longer case than the other two above.

Run the longest case you can. Be it 16" or 20". small case 14" mufflers tend to be louder IMO.
 
My free advice so take it for what it's worth;

Do not run a chambered muffler. I have run the long case Dynomax Super Turbo with good results. May need resonators to cure drone at cruise rpm depending on your rear gear ratio.The longer the case the quieter and less drone.

I have magnaflow on my 454 truck and Borla Pro xs on my 440 Duster. The Borla is really tame until you get on it. The Dynomax Ultra flow or the pypes race pro would be good choices also.

I am getting ready to throw the single flowmaster exhaust on my Newport in the trash and will be going with the Ultra Flow most likely as it comes in a longer case than the other two above.

Run the longest case you can. Be it 16" or 20". small case 14" mufflers tend to be louder IMO.
@Welder guy Marlow is running Dynomax on his and is quite happy with them once he added resonators so that is my direction I think.
 
I've been down this road. If your wife is that sensitive, you need Walker mufflers or the biggest stock-type mufflers that will physically fit. Cadillac mufflers like Big John said? The b-body guys used to use '73 (?) Imperial mufflers as hemi muffler knock offs? All of the high flow mufflers, and I've tried many kinds, just have different amounts of loud or different pitches, but still loud. Maybe Walkers and some exhaust cutouts?
 
Summit brand turbos and full tail pipes. 2.25 or 2.5"
Or if it has to be silent, an OEM type walker
 
I see the Dynomax being recommended here a bit... My experience with the Dynomax mufflers that TTI supplied was that they got louder after a couple years.

I think that the fiberglass matting burnt out. In hindsight, I should have opened one up after I pulled it off, but it was trash day and the can was right there.
 
Drone is, basically, the sound bouncing around in the pipes. Performance mufflers don't do much to help curb this. Most big cars and A LOT of today's full size trucks have resonators somewhere in the system, generally in the longest section of pipe. I sell exhaust for a living, so this kind of question comes up almost daily. Flowmaster's chambered mufflers{unless you opt for the 50, 70, or 80 series} will drive your wife crazy. Magnaflow is a different type of muffler it's got a perforated tube surrounded by fiberglass. This design is quite a bit tamer, so to speak, size for size with Flowmaster. The larger the case, the quieter it will be. Most mufflers get larger in each direction the longer it gets. So, say you want a 22" long case, well then the oval will most likely be a 5x9 or larger oval. Which probably won't fit under your car. I can't speak to how your current mufflers are configured, like a center inlet\offset outlet or the oval and length dimensions. Get these measurements and visit Flowmaster's website. They have a "find it by dimension" page. Start there, then see what others offer too. I will end with this, my 75 Royal has a 400 and a single exhaust. The previous owner had the exhaust replaced from the Y pipe back, with a 14" Turbo muffler. At speed you can only hear a hum. At idle, it sounds great. I'm sorry for the lengthy reply, but it sounds like your choice is really important in a very personal way. But, please keep in mind once a muffler is installed and used it's yours. Choose carefully. Good luck.
This is great to know. The previous owner of my '67 NY'er put FlowMasters on it (not sure what series), great sound at idle, and a bit of a drone at speed...I have a high threshold for that kind of noise, and since it breathes/idles so smoothly, etc., I'm leaving well enough alone, but that won't work for everyone...... I'll be interested to see how this pans out.
 
I have a 65 and a 66 300, both had that dam drone, both have TTI exhaust. I put Vibrant brand short bottle style resonators on both. The drone is cut by 70% and still has a nice sound. On the 66 they are on the tail pipe and on the 65 they are under the front seats, I think the ones under the seat work a little better.
 
I have a 65 and a 66 300, both had that dam drone, both have TTI exhaust. I put Vibrant brand short bottle style resonators on both. The drone is cut by 70% and still has a nice sound. On the 66 they are on the tail pipe and on the 65 they are under the front seats, I think the ones under the seat work a little better.
@Dobalovr , you know that 65:rolleyes:
 
If you really need quiet, maybe add a set of resonators (glass packs) in the tail pipes behind stock-type mufflers like Hemi cars do. I've been considering this myself
 
I went to 1968 Cadillac mufflers on my '70 300. Walker #21856. I had the Turbo mufflers that came with the TTI system and the Caddy mufflers are much better. Still has a nice rumble, but no drone.

Another thought is to use cheap glass packs as resonators. I've done that with good results.
Were the 68 Cadillac mufflers a direct fit?
 
Were the 68 Cadillac mufflers a direct fit?
For the 2 1/2" TTI exhaust, yes it is a direct fit.

Turbo on top, Caddy on bottom in this pic.

p9M9vbS.jpg


Caddy on left in this pic.

OHFKbKt.jpg
 
I’m the guy that loves horsepower, but can’t stand loud exhaust. I played around with various types of exhaust systems to achieve what I like. On my 12 second 1/4 Buick GS I run long case Walker 17749 Mufflers through a 2 1/2 inch system. Very mellow and quiet. A mistake that I made: The system had a balance tube for years that I cut out of the system with some impatience. When I had to remove the transmission to reseal it. Balance, tube makes a definite difference in quieting the system overall.

Steve weim55 Colorado
 
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