The quietest muffler
 

Hello all who traveled down this road before me.
I have a 72 LWB with an original 350, currently with a single muffler and. Y pipe.
I am working toward a daily driver and would like a quieter ride.
My question is what muffler have you all found that works AND is quiet.
I am leaning towards the H or X pipe with duel mufflers.
Any advice is appreciated.

Re: The quietest muffler
 

just took off a flowmaster 50 delta flow 3 chamber as it was to much in the cab for me on my 87 k30 truck . the newer stuff is louder than the older stuff was .

now i did a walker quiet-flow s.s. stock style replacement and LOVE IT !

and to boot it was 63 bucks to my door off rock auto . the flow master was over 100 bucks .

Re: The quietest muffler
 

I'll be aiming for the quietest option I can find, too. I'm not that far along in my project yet but my experience with other pickups says that late model factory take-offs are going to be the quietest.

Re: The quietest muffler
 

The quietest system you can buy will be single exhaust, because the two sides get combined into higher frequency harmonics in a single exhaust system. The higher frequencies are more easily attenuated (quietened) in the exhaust system. That said, an H pipe does almost the same thing, in a dual exhaust system. I have no experience with using an X pipe, though. When I redo the exhaust on my truck, I'll be using Cadillac mufflers, since they are pretty much the quietest. One of them flows enough to not choke a 500 CI engine, so two of them on my 400 CI engine should be OK. Just remember that the initial cost might be high, but the mufflers will keep your truck quiet until your grandchildren inherit it.

Re: The quietest muffler
 

Stock replacement muffler isn't trying to sound like anything. Get a bigger than stock application, such as Cadillac, and it will even be quieter

Re: The quietest muffler
 

I can validate that, Growing up in Detroit we heard stories of how quiet the Cadillac's were. So when we were capable my friend and I took out his parents El Dorado for a spin while they were out for dinner.

That High School football field did not look the same for some time to come!

Re: The quietest muffler
 

And if you have room add a resonator before the muffler, it will cut noise way down. I had the local shop put a stainless header and muffler on our old Jeep zj with straight 6 and I removed the cat. He stated that the straight 6 gets a very annoying drone without the cat. I had him install the resonator and he couldn't believe what a difference it made.

Re: The quietest muffler
 

I always thought resonators went at the end of the tail pipes.

Re: The quietest muffler
 

Definitely Caddie mufflers used to be the quietest. All the guy's running big cam, big compression engines with headers ran them to keep off the police radar. Back in my day they wrote a lot of tickets for loud exhaust among other nit picked items.

Funny thing is those high compression pop's going thru the exhaust system with caddy mufflers sounded like thumping a aluminum can all along the length of the system, it actually sounded pretty good.

Re: The quietest muffler
 

As others have mentioned, a stock replacement luxury car muffler is the quietest. But in the realm of performance mufflers, it’s hard to go wrong with what used to be called the DynoMax Hemi turbo muffler. Now I think it’s just the DynoMax turbo muffler with the 20” case. I have a set on my Jimmy that have been there for 20years now, and another set for my short bed as soon as it gets its 427.

Re: The quietest muffler
 

I'm considering Caddy mufflers for my raised compression choppy cam '72 K2500. I'm liking the idea with a motor anyone who knows anything will still take notice of without the typical HP exhaust note.

Re: The quietest muffler
 

I agree the Dynomax Turbos are really quiet. I installed a pair on a friends Vette and was expecting it to be fairly loud but to my suprise they silenced the 350 SBC. The only time it sound even slightly agressive is under throttle, even then I cant hear anything with the windows up. The car does have cats.

Re: The quietest muffler
 

So how do you get these Caddy mufflers? Just go down to the Cadillac dealership and tell em you want some mufflers? Can anyone help with a little more specific information?

Re: The quietest muffler
 

Pick a quality OEM replacement, like Walker, in the year Coupe DeVille, El Dorado, whatever with 500 cu in you want. I guess in these years would be good. I haven't bought any before but that's what I'd do. I have a lot of parts on my truck that go by a different application on my truck. I just pretend I have that vehicle when I go for new. Like spark plugs are '75 Vette and front brake hoses are '75 C20

Re: The quietest muffler
 

Ok thanks. I'm actually starting work on my panel again and have zero desire for a loud exhaust, and Ill be running a 500 CI Caddy so there's that haha.

Re: The quietest muffler
 

Those mufflers are also quite low back pressure, when you consider that ONE is used behind a 500 CI engine and doesn't choke it.

Re: The quietest muffler
 

Just wanted to say thanks to all of you who replied.
Just becuase I'm slow... so again? Does the H pipes or X pipes actually provide any benefit?

Re: The quietest muffler
 

Your homework- :D

https://www.carid.com/articles/are-x...t-systems.html

Re: The quietest muffler
 

Awesome! Thanks!

Re: The quietest muffler
 

They usually go before the mufflers. They cancel out certain sounds as opposed to deadening the sound in general. On modern vehicles they're usually around the midpipe location.

Re: The quietest muffler
 

I know the modern stuff is probably different. I just bought a exhaust kit for a 71 Chevelle and it came with resonators right at the end of the pipes by the gas tank from inline tube. It's supposed to be exactly like the original ones came. Maby it was different back then.

Re: The quietest muffler
 

Resonators always came in the tailpipe after the muffler. Newer vehicles have cats that act as resonators and mount in front of the muffler. What vehicle are you saying has resonators in front of the muffler(s)? There are modern vehicles with cat, resonator, and muffler? Is the resonator in front of or behind the cat?

Re: The quietest muffler
 

Both the 2008 Range Rover, and the S197 mustang I've done exhaust for had cats, into resonators, into mufflers (or in the RR's case a big shared muffler). I believe the 2013+ Mustangs do it too, except they have a shared center resonator, into dual mufflers. On these systems it's CAT > Resonator > Muffler. My guess (and it's just that) is that mufflers work more efficiently if the resonators have already done their job and canceled the sound waves intended, rather than having the muffler quiet them, and then cancel them later on.

Here is a 2013(ish) Mercedes C300 stock exhaust. Shared resonator, into dual mufflers: https://mbworld.org/forums/attachmen...n-dsc05921.jpg

Re: The quietest muffler
 

All that said I didn't realize older cars it was the inverse.

Re: The quietest muffler
 

I did mine by accident I went out and bought 42-inch glass packs and 2-inch pipe without an H pipe exhaust that came out behind each rear tire's and Mine is so quite Its so nice By accident. I went out and had me build a 1993 5.7 Roller motor with a stock truck cam this is the motor with the mechanical fuel pump only made it one year. I went out and exhaust that came out behind each rear tire I run the stock ram horn exhaust manifolds and its a dream to drive Its a nice old farm truck