Video: Classic Flowmaster Muffler Sound Test On A Musclecar

Our sound test mule: this 1972 Dodge Challenger with a 408 ci stroker.

When it comes to the classic Flowmaster sound, there are a number of choices for performance mufflers. Depending on whether you have a mild, daily driver or a full on musclecar with over 500 ponies under the hood, there’s a muffler for you from Flowmaster Mufflers. But what happens when you make that decision for a new Flowmaster muffler and it’s not what you expected? Sometimes the rumble is too much, and other times it’s just not enough, and there’s no way of telling which one is the one you truly wanted.

Well, Flowmaster has asked us to help out with that dilemma, and we gathered up eight of their most popular performance mufflers and installed them on a 1972 Dodge Challenger with a 408 stroker. This Challenger belongs to Adam Miles, and was built by Todd Back in San Jacinto, California. It packs 550 horsepower at the crankshaft, and it’s the perfect test mule for our muffler sound test. For this sound test, we also installed Flowmaster’s header-back 3-inch exhaust sytem (part #17379); it’s an aluminized steel system complete with H-pipe and Flowmaster’s Super 40 mufflers.

Eight of Flowmaster's popular mufflers were put to the sound test. Which one is best for your musclecar? Find out by watching the video above!

Mild Sound

But we’re not just installing one set of mufflers to let you know how it sounds on this musclecar. We’re installing eight different pairs of mufflers and not only firing it up, but also doing a road test with all eight mufflers to give you an idea of what you can expect from outside of the car, and from the inside as well. We started with the mildest of the bunch, the Super 50, which is a great muffler for a daily driver who is looking for the classic Flowmaster sound with very little interior resonance.

This muffler – and all of the others that we tested – will have a slightly different sound on a musclecar with a 2.5-inch or smaller exhaust, and a little less horsepower. As power and exhaust pipe size increases, so will the sound and the resonance. Reading in at about 83.0 decibels, the conversations and music won’t be drowned out by the sound of the muffler, and yet it will still provide you with a great performance sound.

Swapping eight pairs of mufflers is very time consuming, but we did it to get the facts.

Moderately Aggressive Sound

After the Super 50, we installed the moderately aggressive sounding mufflers, including the 50 Series Delta Flow, and the Pro Series – a patented laminar flow design. These mufflers give a little bit more aggressive sound, but they won’t be so loud that you can’t hold conversations inside the car. They’re noticeable without being overly deep, while giving your musclecar the sound you were looking for. These are some of the popular choices for those who want a bit of an aggressive sound but don’t want the really deep rumble that Flowmaster is known for. These mufflers work great on a mildly built musclecar with about 300-400 horsepower.

The 3-inch exhaust was an upgrade from the 2.5-inch exhaust that was previously on the car.

Again, we’ve installed the entire 3-inch header-back system, but on a lesser musclecar a 2.5-inch system is a better choice for exhaust size. Since we’re working with more power and a classic musclecar that needs the room to breathe, the smaller system would be too restrictive. The 50 Series Delta Flow adds just a slight more tone without being overbearing, and the Pro Series is a step up from there with it’s open-header theme in mind and the closest to a straight-through design. It’s available in three-inch all the way up to a five-inch inlet and outlet. These mufflers read in at just over 83 and 84 decibels, respectively, so it’s still pretty tame inside the car during a normal cruise.

Aggressive Sound

The complete header-back system included the mufflers and the exhaust tips.

The aggressive mufflers we installed afterwards started with the 40 Series Delta Flow, the Super 40, the Original 40 Series, the Super 44 and finally the smallest and the loudest of the bunch, the Super 10. When we got to the aggressive mufflers, the sound picked up quite a bit, and interior resonance increased. If making your presence known is what you’re looking for, then these aggressive sounding mufflers are the ticket. You can tell that the sound is picking up, and that this Challenger is starting to match its sound to its looks.

There are a few mufflers that will give you the deeper rumble that makes a musclecar sound just right, but keep in mind that going to the more aggressive mufflers will drown out the interior conversations a bit, especially during heavier throttle situations. When you’re putting the pedal down, you can see from the video that the interior sound has picked up a bit, reading in at mid-85 decibels for the 40 Series Delta Flow, to just over 92 decibels for the Super 10.

After testing all eight mufflers, the Super 44 was the classic Flowmaster sound that car owner Adam Miles chose for his Challenger.

If you’re planning on performance and the deepest sound from your Flowmaster mufflers, you can tell that the tone gets even deeper with each of these aggressive muffler installs. With the Super 10, you can just about forget about normal conversations because as the pedal goes down, the interior sound goes up. The Super 10 is a 409S stainless steel muffler with a limited lifetime warranty, and if you plan on driving with this muffler, plan on announcing your arrival.

So which muffler did Miles choose for his Challenger? He loved the sound of the Super 44 and that’s the muffler that ended up on his car. Be sure to watch through the end of the video for the burnout that was graciously done for us. Hopefully this video will help you decide which muffler better suits your ride, and still give you the classic Flowmaster sound. Check out Flowmaster Mufflers web site for more information and additional sizes and styles for each of the eight mufflers featured.

You just can’t prove it’s a musclecar without the obligatory burnout at the end of the video!

About the author

Michael Harding

Michael is a full time Power Automedia writer and automotive enthusiast who doesn’t discriminate. Although Mopar is in his blood, he loves any car that looks great and drives even faster.
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