Quiet Performance Mufflers/Exhaust

Discussion in 'Technical' started by Phil, May 11, 2016.

  1. Phil

    Phil Member

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    I drive my Maverick every day, and I'd like to make it quieter. It has headers, H-pipe, hi-flow flowmaster cats, and Magnaflow SS mufflers with tails exiting out the rear. I had some sort of cheap turbo muffler on there before and they were even louder. My buddy has the magnaflows on his crown victoria, and they were fairly mellow, which is why i put them on my maverick. They sound great, but too loud, and at times droney

    Does anyone have suggestions on mufflers that would be significantly quieter. I don't need it to be whisper quiet, but it needs to be significantly quieter than it is right now.

    Thanks
    -Phil
     
  2. 71gold

    71gold Frank Cooper Supporting Member

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    "H-pipe, hi-flow flowmaster cats, and Magnaflow SS mufflers with tails exiting out the rear."

    that sounds quite to me...:yup:
     
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  3. Phil

    Phil Member

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    haha, yeah i've tried my best, it's not deafening, but for trips more than 30 minutes i need ear plugs or i'll get a headache.
     
  4. 71Mavrk

    71Mavrk Member

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    Have you tried a metal block off panel and some sound deadening behind the rear seat?

    Except for the cats, I have a similar set up and don't find it to be very loud at all.

    Micah
     
  5. Phil

    Phil Member

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    I have a plywood blockoff, with high grade carpet padding in between, and under the seat. Would a steel blockoff help more?

    I suppose anyone's opinion of "loud" is subjective. If i drove this on weekends, or from time to time, it would be perfect, not too loud, but since i drive it every day, its annoying raising my voice to talk to people, or not being able to hear the radio properly even at louder volumes to hear it
     
  6. RMiller

    RMiller My name is Rick

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    I have been considering this for a while and thought I might go with Z06 mufflers. OEM mufflers that support a bunch of power and they have an internal valve that allows them to bypass the baffles but quiet under normal conditions.
     
  7. Crazy Larry

    Crazy Larry Member

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    I don't think there's any such thing as a "quiet" performance muffler. They are either quiet and restrictive, or loud and free-flowing. A longer muffler will be less noisy than a shorter muffler. A muffler with fiberglass or steel wool packing will be less noisy than a chambered or "turbo" muffler. Larger diameter pipes will be louder than smaller pipes, and headers will be louder than stock exhaust manifolds. Some cars have mufflers and resonators, but there's no room for both on Mavericks unless it's the stock single system.
     
  8. Pony Express

    Pony Express Haul'in @**

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    "Larger diameter pipes will be louder than smaller pipes."

    Absolutely no question about it, so what is the diameter of your exhaust?

    My Bronco has 3" exhaust off of the header collectors with high performance cats with Bassani Mufflers exiting behind the rear tires. Sounds great - to a 17 year old, but obnoxious as all hell otherwise and certainly doesn't hesitate in awaking the entire neighborhood with early morning departures. That, and increased decibels are mandatory when having a conversation - Bluetooth is especially challenging.

    I suppose I've just stated what to avoid...
     
  9. mercgt73

    mercgt73 Member

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  10. ADOR

    ADOR Member

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    I haven't personally tried it but one trick I seen in hot rod magazine years ago was a guy had 3" pipes and about 6 inches from the rear he had a butterfly put into the line to completely shut off his main pipe and make the exhaust go out some 1-7/8" pipes that exited right beside the 3" pipes. The main said it made it sound much quieter. If he seen a cop or needed to make it quiet all he had to do was hit a switch.
     
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  11. groberts101

    groberts101 Member

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    Was going to be my recommendation too. You'll give up a few top end horsepower but those mufflers sound excellent and offer a great mellow tone at idle and part throttle.

    Also consider that resonance is created when the exhaust system is not effectively isolated from the chassis. OEM has it figured out and there's much to be learned from those designs in comparison to the cheaper aftermarket offerings.

    Pictures could help us see what may be more easily remedied.
     
  12. rotorr22

    rotorr22 Member

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    Or it can be just the opposite, where the chassis itself acts as a dampener. Sometimes you can add mass to the system to tune it out, but it usually comes down to the RPM where the system becomes resonant and too often, that it is where you cruise or otherwise dwell a lot. As Crazy pointed out, we have little real estate to work with. I would indeed try some different mounts and make sure everything is tight. Easy to do before you get into spending more time and $$$.

    Just remember that "drone" and decibel level of the exhaust system are two different animals.
     
  13. groberts101

    groberts101 Member

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    Right.. I assumed it was resonance(which can happen over a much wider range..adds decibels).. or drone(which is often the strongest and most obnoxious part of the resonance at light cruise rpms.. adds nearly intolerable vibration to eardrums).. which is caused more by chassis vibration than by exhaust vibration or tone or outright decibel level.

    And not to argue.. I prefer to call it "comparing notes".. but I have never once seen where a chassis has quieted down an exhaust system since it is the inherent vibration of the exhaust system itself that gets amplified by the chassis vibration being added into the mix.

    Another few tips for the OP to better isolate(pun intended) the issue. LOCATION of the hangers makes a difference. Locating them near larger open floor pan sections without as much gusseting/bracing can turn your floorboards into big tin speaker cones.

    Quick and easy test is to relieve all exhaust hangers while the car is up on stands. You'll need at least 4 more stands/supports on the exhaust at midpoint and rear to keep from stressing the header gaskets and various connection points. This does two things simultaneously. It obviously isolates the system from the chassis/floorboards to get rid of the added vibration that it may be.. most likely IS.. adding into the equation. Secondly it creates space underneath the rear ends tunnel (doghouse) to get rid of sound wave reverberation caused by the tailpipes being a bit too short. Even just the angle and running tucked tips a few inches too short on the tailpipes can make a substantial difference for interior sound intrusion. I've done substantial testing in that area (mainly because i hand build all my systems and moreso due to running flow masters and straight thru mufflers like MagnaFlow that are more prone to causing these types issues) and if in fact they are causing moderate to severe reverberation under the rear of the car?.. adding 2-4" temporary tip extensions can even change the tone and quiet the car from the EXTERIOR.. and much more so on the interior. This ultimately leads to slight redesign of the tips as you move away from what looks cool.. to saving your eardrums. Ideally, the quietest version will exit directly to the rear vs out to the sides at an angle. That allows the rear of the car to act as a slight sound block vs the side angled tips allowing more of the sound to come back up both sides of the car towards the windows. Especially important if you do a lot of cruising with the windows rolled down.

    Point is.. find some nice stretchy and compliant OEM type hangers(not much can be done for the header connection but the entire system needs to float separately of the car) and also add some temporary tip extensions. I have watched others reactions and know you will be surprised at how those few things can affect interior noise levels. In fact, the results are good enough that it has stopped more than a few from replacing mufflers like you are about to do here. And.. I have done it to far larger and louder systems on more powerful combinations using far less muffler than this particular combination of parts. Hope this helps.
     
    Last edited: May 12, 2016
  14. 70GreenMonster

    70GreenMonster Member

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    Check out the Flowmaster 70 series. It was recommended to me by Flowmaster for a Grand Touring car build.
    It is supposed to maintain high flow without being loud and drone minimal.
    They are large.
    Available in 1 in 1 out, 1 in 2 out, 2 in 1 out, center or offset.
    I have not checked cost yet, I am a long way from exhaust yet.
     
  15. Phil

    Phil Member

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    Let me see if I can explain my setup better. The headers are "homemade" from the previous owner (he was a hack), the system is mostly 2.25" dual exhaust. I say mostly because the pipes coming out of the headers are 2.5", that go into 2.25. The hangers are right before the bend for the axle, and a foot back from the tailpipe end. They are cheapy hangers, with minimal rubber dampening. The tailpipe end is pretty much even with the rear valence.

    I'm aware of decibel, and drone differences, I'm at about 77DB in the cabin at idle, and a bit more cruising ( i think around 80/82), the last time i measured it. Less drone would help a lot though. The magnaflows shifted the drone to a more favorable RPM, no doubt about that.

    Everything is quite tight.

    I was considering using stock mufflers (for late model camaro, or something) That is known to put out power, but still keep the noise down. The problem seems to be the mavericks are limited as far as how long a muffler you can run...im not sure of what that limit is. My magnaflows cases are 14"
     

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