Performance Mufflers: Theory-of-Operation and Selection as published in British V8 Newsletter, Volume XV Issue 2, September by: Larry Shimp The focus of this article is on the silencing efficacy of an exhaust system, and how to get the minimum sound with the minimum flow restriction.
This may not be of interest to everyone, but for those who want to drive for long distances, especially with air conditioned cars and closed windows, this may be more applicable. Source of noise: The combustion process and exhaust cycle of the engine impart vibrations to the air stream that make themselves known as noise. Noise tends to increase in volume as an engine gets bigger and as compression increases, and to increase in frequency and volume as engine RPM is increased.
Muffler principles: There are four main performance muffling principles: expansion, "turbo", noise cancellation, and noise absorption. Old OEM mufflers worked primarily by restriction, but these will not be considered for performance use. Dale Knapke's Supertrapp mufflers utilize the expansion principle.
Expansion Expansion is one of the oldest designs and works by letting the hot exhaust gases expand and cool so both their velocity and volume are reduced. These mufflers are simply long, big diameter tubes with no internal baffles, usually with an increasing diameter from the inlet to the outlet. As the exhaust gases slow down, the amplitude of the noise they carry is reduced. Expansion is relatively efficient in that the exhaust flow is not really hindered.
Unfortunately, it is only practical for smaller, low power, low speed engines. It worked on Model T Fords and similar cars, but modern V8s put out too much exhaust volume for any reasonably sized expansion muffler to take care of. However, hybrid expansion mufflers are still around.
The megaphone mufflers seen on some motorcycles work by expansion in the increasing diameter exhaust tube, and by sound absorption in the fiberglass lining. This is also the fundamental principle of SuperTrapp mufflers without the plates installed. Chambered mufflers look externally similar, but utilize the "noise canceling" principle. Please support the sponsoring companies who make BritishV8 possible, including:. Turbo "Turbo mufflers" are a variation on OEM style mufflers, but are less restrictive, so they are in the performance category.
They were originally developed for the early GM turbo cars especially the Corvair because the turbocharged engines didn't like back pressure.
Besides, the turbochargers already provided some muffling effect through expansion and cooling, so less sound attenuation was required from the mufflers. Turbo mufflers consist primarily of a pair of parallel, perforated dead-end tubes, sometimes with a baffle in between. Old style OEM mufflers are similar but usually have smaller tubes and less perforations, and sometimes extra baffles.
The exhaust escapes from the holes in the inlet tube, and exits through the holes in the outlet tube. Noise cancellation is by restriction, which slows down the exhaust gasses, and by some noise cancellation as sound waves get reflected among the many inside surfaces. There is some case resonance, but the sound is otherwise similar to noise absorption mufflers.
Chambers Noise canceling is the principle used in chambered mufflers. A well known manufacturer of chambered mufflers is FlowMaster. Although they externally resemble "turbo" mufflers, their internal construction is quite a bit diferent. Chambered mufflers have a series of compartments that are designed to cause the sound waves to be reflected back on each other.
Sound waves have peaks and valleys. If two waves are degrees out of phase so that the peak of one wave corresponds with the valley of another wave, the peaks and valleys will cancel and the result is silence. Noise canceling ear phones work by electronically generating signals exactly degrees out of phase to detected noise signals.
The ultimate car interior cancellation system is therefore an electronic noise canceling circuit that sends counteracting sound waves through the car's speaker system. This would let the driver determine the amount of interior noise at the turn of a dial. Prototype systems actually do exist, and I understand that some car companies were considering such a system for their production cars. Enjoying this article? Our magazine is funded through the generous support of readers like you!Display Options.
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If you are an international customer and would like to change the currency that prices are displayed in, you can do so here. What is this? Muffler, XR-1, 3 in. Outlet, Brushed Stainless Steel, Each. Loading Tomorrow Estimated International Date Loading Today. Muffler, 2 Chambered, 2. Inlet, 2. Muffler, Pro XS, 3 in. Outlet, Steel, Black, Each. Muffler, 2.
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NOTE: Overall length is approximate. Use the body length to determine what muffler will best fit your application. It may be necessary for an installer to shorten or lengthen the bushings, or modify the diameter for proper fit into your application. Powerstick bushings are expandable. An experienced exhaust installer will know how much the steel will stretch.
NOTE: 2. The best of both worlds. Click here to see a Corvette sidepipe retrofit using 2. Thanks to L. Here's his commentary:. I bought a 65 with sidepipes and posted a similar problem a few weeks ago. They were an original repro. Just yesterday Mon. ERIC at Classic, said he had never tried this particular combination and hoped it worked.
I made an HD video of the before and will be doing one in a few days to show the difference. It may be hard to hear the sound difference on a computer. It is a lower rumble and they are still louder than most exhausts.
The original sound was very annoying and the new sound has a much better tone. When I finish the video I'll post both of them. Since installing a set of OBX Stainless side pipes I've been trying to find a set of inserts that flowed well but sounded good at a reasonable volume. I started with the Hooker Max Flows that sounded nice at idle but after that they were super loud and unbearable on the interstate.
Second I tried the Hooker regular glass packs not reverse flow and they sounded much better volume wise but the tone was just ok but the back pressure was horrible. He said no problem though he'd never made a set for the hooker styled pipes but was game. A few weeks later they arrived and I started the install. The design is great and easy to bend the tabs so the inserts slide in with some resistance and no vibration and rattles.
Cherry bomb vs. Smithy's mufflers
Atomic Industries www. Register now to get rid of these ads! The H. Cherry bomb vs. Worth, TX. Opinions on better quality, sound? Going on a 8ba flathead. Thanks guys! Brockmans are good and they will custom build what you want. I have also used generic glasspacks for years with good luck. I like my Smithys on my 21 stud Slick WillyNov 26, Search for this; Poll: Muffler Poll - Haven't seen one here V4FNov 26, Flatheads and Smittys' are a hard to beat combo for sound! JeffB2Nov 26, I use no mufflers.
Straight pipes is the way i go! Joe DaddyNov 27, I was running cherry bombs on my high school ride I always liked the bomb sound and performance so I never switched. So I guess I didn't really answer your question did I? Oh, well I guess if I was really ol' skool and kool and would run straight pipes Missing LinkNov 27, Choosing a muffler for your vehicle is one of the main tasks you can do to improve its performance.
It is installed for the noise reduction that comes from the exhaust system of the automobile. One of the vital parts of your car is the muffler. Chambered, turbo, and straight-through mufflers are the most common types of mufflers for your vehicle. It minimizes the sound pressure that the engine creates by using acoustic quieting, which is different in a chambered mufflerturbo, and straight-through mufflers. The exhaust volume is reduced to tolerable-levels which allows the sound of your vehicle to go as smoothly as you prefer it to be.
As your engine generates lots of pulsating noise as the exhaust valves open up and releases highly pressurized gas, the muffler does its job by regulating the noise it emits. If you are thinking of what muffler type is right for your car, then consider these three most popular styles and compare them in terms of performance and sound. Read on below to find out more about your ideal muffler:. They typically have a raspy sound, and depending on its design, you will have a classic muscle car tone coming from your car.
This is if the baffles and chambers within the muffler are finely-tuned. Chambered mufflers work when exhaust is routed through multiple chambers and around ant number of angled, sound-cancelling plates known as baffles. This boosts exhaust flow, increases horsepower, torque, and fuel economy. Aside from that, your vehicle will have a rumbling, slightly metallic exhaust tone that is sure to make your car stand out.
Turbo muffler has a series of perforated tubes and the exhaust gases are guided through the muffler in an S shaped pattern.
There are individual perforations that can actually peel of the sound waves. This style of muffler has a sound deadening material which will give you a deeper exhaust note. This can be used on any car, whether it is turbocharged or not. The benefit of using a turbo muffler versus a stock muffler, it adds horsepower and attitude.
They give engine exhaust an easier path to follow. Turbo mufflers direct exhaust flow using 3 or fewer perforated tubes which means that it changes directions less. With this, engine exhaust leaves the muffler faster which increases horsepower and provides a better tone.
It is also important to note that turbo mufflers use additional fiberglass packing around the tubes for additional sound control. Turbo mufflers sound can vary widely in volume and tone, and tend to quieter than a chambered or a straight-through muffler.
A straight-muffler, also called a glasspack, is a type of muffler with the simplest looking design. From its name, it has a straight-through design wrapped in a fiberglass packing. It is compact which adds to its advantage, which is good for limited-space situations.
This is perfect for you if you are looking for a traditional style muffler.A good Glasspack muffler is one of the best mufflers present in the automotive world nowadays. The design is simple. The exhaust passes through the center of the pipe and the padding around the exhaust pipe muffles the vibration and sound of the engine. But this variety of muffler does have its advantages and disadvantages too.
Glass pack mufflers work on the simple principle that all the sound generated by the car engine is passed through a sound absorbing material before it is released. This means very little sound is allowed to escape the muffler, and the sound blanketing capacity of the muffler is excellent.
Several people commonly refer to the Glasspack Muffler as the Cherry Bomb Muffler due to its really great sound muffling abilities. These mufflers are also much better than ordinary mufflers, as they do not allow the sound to resonate back into the engine.
This usually happens in ordinary engines, causing them to dissipate without damaging human ears. The loud sound of the engine is negated by the same loud sound produced by an ordinary muffler. But this creates negative pressure on the engine. The glasspack muffler reduces the pressure on the engine by dissipating the pressure of the loud sound waves out through a sleeve of glass particles.
Glasspack Mufflers don't really work on every kind of car. Another problem is that as they do get old, they start to sound really bad. They require regular care too. But on the whole Glasspack Mufflers are pretty good. They offer value for money and have a good capability for absorbing sound.
But make sure you check with the garage before you get them installed. Saved Vehicles 0 Saved Searches 0. Cars Direct. Home Aftermarket Parts Performance Parts. Featured Stories. Advantages and Disadvantages of a Glasspack Muffler. Advantages of Glasspack Mufflers Glass pack mufflers work on the simple principle that all the sound generated by the car engine is passed through a sound absorbing material before it is released.
Disadvantages of Glasspack Mufflers Glasspack Mufflers don't really work on every kind of car. Interested in Leasing? Select a Make. Select a Model. Find Used Cars Browse a huge selection of local inventory.
Recent Articles. Get Affordable Car Insurance Let us help you find affordable insurance. Get Quotes.Using the best glasspack muffler in your vehicle is the right choice. These are the most basic type of muffler that can be found on vehicles that are performance-optimized.
Moreover, there is a perforated exhaust tube in the middle of a glass pack muffler. Undoubtedly, the best muffler for trucks, cars or jeeps that make use of an angled tube is a more noiseless option, whereas the versions that have a straight tube are the ones producing loud sounds.
Most of the mufflers have a unique design and perfect mechanical structure that does not have lots of restrictions, which makes them capable of building more horsepower whereas producing deep tones from the exhaust. When compared to turbo mufflers, these are perceptibly louder. The extent of the muffler volume ranges from above-average to deafening in loudness.
Top-rated glass pack mufflers come with plenty of benefits, which make it worthwhile to set them up. These yield a prominently aggressive sound which seems to be amazing during performance rides.
7 Most Silent and Affordable Quiet Performance Mufflers
If you have decided to set up a glass pack in your car, here are some glass pack mufflers that are worth choosing from. The glass pack muffler has the distinctive mellow and deep sound of the Cherry Bomb, which revolutionized the automobile muffler industry in This particular muffler is 12 inches long and the diameter outlet and inlet sizes measure 2. An aluminized steel muffler is powder-coated with a red coating that keeps it safe and also makes it look nice in appearance.
However, its short size makes it too aggressive. But if you are looking for a raw sound from your vehicle, this is an option you should look at.
It is capable of supplying the optimal horsepower and lower back pressure due to the straight-through design. High in performance, it has universal header styles and fit. If you are in search of a muffler that produces loud enough sound to command respect on the roads, this is a piece that is worth buying.
Thrush glasspack muffler in an ideal for those people who need a mellow sound that is not unpleasant to the ears.
It has a throaty rumble and the straight-through design has a nice effect on the sounds produced. We can say without any doubt, this amazing exhaust muffler is one of the best performance muffler units on the market at present for its high performance and compatibility. Average bulk and dimensions make the muffler a perfect fit for vehicles.
It is slightly short in size, but the build is more appealing than the square and ugly ones that can be found out there. You can easily set it up in your vehicle.
If you live in a close neighborhood, you can choose this high configured muffler. You can get a loud, deep tone with this glass pack muffler. Sincethe Cherry Bomb has been the real high performance glass pack muffler. It has the classic mellow but deep sound that one has come to expect from Cherry Bomb mufflers.
These exhaust kits are containing optimal horsepower and lowered back pressure owing to the straight-through design. The rumble is quite audible, which is neither too soft nor too loud. Keep in mind that the longer the size of the muffler, the lower the sound that is produced.
Cherry Bomb vs Thrush
That means, the shorter the muffler that you buy, the louder the sound that can be expected. It has a universal fit and can go with almost any type of car out there. You will have no problems setting it up.