MUFFLER OPINIONS
- Thread starter WAYNE0
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VOETOM
Well-Known Member
We have done lots of muffler testing and I wanted to share why the Dynomax Super Turbo works as well as it does for sound level control, tone, and airflow/performance.
In Cutaway 1, you can see the basic three pass system it uses. Note the louvers are stabbed outwards. This way, there is nothing in the air flow path to swirl it as much as if they were stabbed inward. This is a 2.5" in and out muffler. The tubes are that large all the way through. No pinching or reducing.
In Cutaway 2, you can see their Flow Directors that do a nice job of reversing the flow direction. They are large and handle the gas flow heading into and out of them pretty well.
In Cutaway 3, you see me holding the glass fiber mat they use. It was chosen for its density and toughness against fracture and blow out and it does a good job at absorbing the high frequency hisses and spits and crackles.
Cutaway 4 shows that the mat is actually wrapped around the center three tubes and all can use it for sound control.
Cutaway 5 shows what the incoming gases see: not much restriction or reduction in pipe diameters all the way through.
The larger of these, the #17748 (HEMI sized) and #17749 big GM other GM A body sizes, work really well. The shorter ones, like this cutaway, are a tad louder and flow a bit less as the gases still get pretty turbulent inside.
NOTE, MOPAR uses offset in center out mufflers and the Super Turbo splits the Flow Director on the outlet side and runs the exhaust over and aorund the outlet pipe. This does impede flow somewhat but not as much as you would think, on typical moderately powered cars anyway.
Pypes now makes some like these too. The Dynomax patent expired on the Flow Directors and PYPES now uses them. Theirs also work pretty well.
These will not flow as much as a straight through muffler but they do a super job of sound control, noise level reduction, making a good growl but not too much, and minimal resonation. The little ones tend to resonate more than the large ones but all are pretty good at avoiding resonation. Large or small, they are far better at minimizing resonation as compared to chambered or baffled mufflers.
In Cutaway 1, you can see the basic three pass system it uses. Note the louvers are stabbed outwards. This way, there is nothing in the air flow path to swirl it as much as if they were stabbed inward. This is a 2.5" in and out muffler. The tubes are that large all the way through. No pinching or reducing.
In Cutaway 2, you can see their Flow Directors that do a nice job of reversing the flow direction. They are large and handle the gas flow heading into and out of them pretty well.
In Cutaway 3, you see me holding the glass fiber mat they use. It was chosen for its density and toughness against fracture and blow out and it does a good job at absorbing the high frequency hisses and spits and crackles.
Cutaway 4 shows that the mat is actually wrapped around the center three tubes and all can use it for sound control.
Cutaway 5 shows what the incoming gases see: not much restriction or reduction in pipe diameters all the way through.
The larger of these, the #17748 (HEMI sized) and #17749 big GM other GM A body sizes, work really well. The shorter ones, like this cutaway, are a tad louder and flow a bit less as the gases still get pretty turbulent inside.
NOTE, MOPAR uses offset in center out mufflers and the Super Turbo splits the Flow Director on the outlet side and runs the exhaust over and aorund the outlet pipe. This does impede flow somewhat but not as much as you would think, on typical moderately powered cars anyway.
Pypes now makes some like these too. The Dynomax patent expired on the Flow Directors and PYPES now uses them. Theirs also work pretty well.
These will not flow as much as a straight through muffler but they do a super job of sound control, noise level reduction, making a good growl but not too much, and minimal resonation. The little ones tend to resonate more than the large ones but all are pretty good at avoiding resonation. Large or small, they are far better at minimizing resonation as compared to chambered or baffled mufflers.
Last edited:
VOETOM
Well-Known Member
And, when looking at data from our testing, the larger and smaller configuration flows about 70% of a straight through 2.5" piece of pipe but the larger one is about 5 dBA quieter at ten feet at 3500 rpm and 2 to 3 dBA at 750 rpm. All were on a 455 cubic inch Pontiac engine. The larger volume really works and all muffler guys at the OEMs used this to tone down the big powerful engines when they wanted to avoid doing so by restricting the exhaust gas flow.
Really quiet HiPo setups used multiple mufflers with large volumes. The more the better if configured right.
This is why Chrysler used to suggest using the big 1971 or so Imperial mufflers. They worked well and it is too bad you can't find them any more. Before the advent of today's Hi PO mufflers (around the early to late 90s anyway) the old single exhaust Imperial mufflers were a super choice if you could make them fit.
Really quiet HiPo setups used multiple mufflers with large volumes. The more the better if configured right.
This is why Chrysler used to suggest using the big 1971 or so Imperial mufflers. They worked well and it is too bad you can't find them any more. Before the advent of today's Hi PO mufflers (around the early to late 90s anyway) the old single exhaust Imperial mufflers were a super choice if you could make them fit.
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340six
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So what does Pypes call them?
When i bought my Pypes kit the guy recomended Street Pro's in Stainless, so that's what I got. I have not installed their system yet. Grabbed the 2.5" X pipe system - and Doug's Header
mopowers
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340six
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Thanks. They said the Street Pro were louder at idle than Race. But were less loud under power. I hope tgats the case. Dougs Headers 10.88 to 1 422 Aluiminum Headed 240/252 @50 ground on 110* 560/570 solid.
It's a,big step down from my current big compression motor.
I just wanted muffs that fit the Pypes pipes so ordered that.
Note)
I have heard both Summit and Jegs turbo pipe muff kits and they were cheaper fit well and sounded good.
It's a,big step down from my current big compression motor.
I just wanted muffs that fit the Pypes pipes so ordered that.
Note)
I have heard both Summit and Jegs turbo pipe muff kits and they were cheaper fit well and sounded good.
Would love to know how all of these different brands compare with the stock-sounding mufflers offered by some companies, such as Accurate. As an old guy, I still remember how nice the 340's sounded from the factory back in the day. As an aside, I have Dynomax Super Turbos on my built Sport 340. They're loud at cruising speed, but that may be because, as I said, I'm an old guy now.
Jeremiah (jd)
Well-Known Member
In my experience turbo mufflers kill power and have tremendous backpressure. As in a 15-25whp difference between a straight through design like a Magnaflow, Gibson (what's on my GTS) or if you are on a tight budget Flow Monster is sold by FlowMaster/Holley and the are very nice for $50/muff.
None of my other cars have tail pipes so I cannot offer much beyond that.
None of my other cars have tail pipes so I cannot offer much beyond that.
WAYNE0
Well-Known Member
When it comes to the Hemi style mufflers (not sure what makes that) sound good & even better over time.
VOETOM
Well-Known Member
Hi Wayne, the "HEMI" designation/size came from their dimensions and that they were used on the HEMI powered B bodies as well as the 383 and 440 versions. And the Little Red truck. They are aorund 20" long, about 4.25 by 10.25" ovals and had offset inlet, center outlet 2.25" inlet and outlet bushings. They are three pass mufflers and the closest sound I've heard to them are the ones Waldren sells although theirs are a little cracklier and more hollo sounding. Their Imposters are a bit louder and more rumbly. The 17748 SuperTurbo matches the sound pretty closely and will pass more air and exhaust gas through them too.
Tom
Tom
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