Mufflers and Resonators

The muffler or resonator is the component of an internal combustion engine that prevents back-pressurization of the gas in the cylinders when no longer needed to power the vehicle.

When a piston continues to push on the end of an empty cylinder, it generates back-pressure which can lead to damage. The muffler’s job is to allow exhaust gases from each cylinder in sequence; this allows for controlled combustion, avoiding back-pressure. Imagine what could happen if all your car’s exhaust were allowed to exit at one point! Without a muffler, your car would be making more noise than you wanted and could even explode if things got too extreme. The resonator component of a muffler is also used to control noise. Some mufflers are designed with internal chambers that resonate at certain frequencies, reducing the resonance of other frequencies heard by the driver.

Mufflers are an essential part of any car, truck, motorcycle, scooter, or other two- or four-wheeled powered vehicle. They are generally attached to the tail pipe on the exhaust system. The tail pipe is located under the car and connects to each cylinder via one or more exhaust pipes. The tail pipe then opens out into a muffler which reduces gas velocity and lowers gas temperature. Without this slowing down process, your vehicle would be creating too much exhaust pressure for road safety and comfort reasons.

The muffler also reduces noise levels in your exhaust system. The amount of noise reduction achieved depends on the build quality, size, and design of the muffler. A well-built muffler will be relatively quiet while a poorly built one will be quite noisy.

A muffler serves two main functions: heat reduction and sound dampening. Mufflers are responsible for up to 90% of the decrease in exhaust temperature. Along with other parts of an engine’s cooling system, this lowers the temperature of gas exiting the cylinders by 75 °C (167 °F) or more during an internal combustion cycle.

The second function of a muffler is to dampen the sound of the engine as it is no longer needed as a source of power. When all engines were mechanically-driven, the exhaust system was designed simply to carry away hot gas from combustion. A separate silencer was not needed because all the noise from mechanical operation could be carried away by the exhaust pipe. In the case of internal combustion engines, a muffler or silencer must be used to prevent excessive noise and irritating vibrations from entering the passenger compartment.

Most mufflers have a long tube that provides a separation between engine and passenger cabin for effective sound absorption through multiple paths.

Will adding resonators quiet an exhaust?

These are resonators. They are not designed to have sound enter them, but rather to take sound out of the system. They are found in both exhaust systems and air intakes. You will often see them mounted low on the firewall of a car engine compartment or integrated into air filters for trucks, cars, RVs and industrial applications.

Many people refer to these devices as “mufflers” when in fact they are resonators. People even use the term “resonated exhaust” when they mean “muffled exhaust.” True mufflers (i.e. mufflers designed to reduce noise) are generally quite large, bulky, heavy and restrictive to the flow of exhaust gas. Since resonators are not used for noise reduction or flow restriction, they can be much smaller and lighter.

What are the differences between “mufflers” & “resonators”?

Silencers vs Mufflers

Silencers are attached to the end of your exhaust pipe. Typically this is where your tailpipe meets your muffler or resonator. These devices reduce sound waves emanating from under your car and keep them from reaching the cabin of your car.

Resonators vs Mufflers

Resonators are not attached to your exhaust pipe. Resonators are designed to take sound waves from the intake system of a car, boat, airplane or other engine and pass them on to a muffler. This can be a very effective way to reduce volume in a system since without resonators the sound waves would be coming from your tailpipe and thus next to you ears rather than from your intake system away from you.

What is the purpose of a muffler?

The muffler’s main function is heat reduction. Through slow expansion of exhaust gas, the hot gases are cooled by contact with cooler surfaces, such as cylinder walls and steel pipes. This process is termed a “heat sink”. A muffler does not stop emission of harmful exhaust pollutants, but helps to keep it from entering the passenger cabin of the car. Mufflers also lower the noise level of your car’s exhaust system by enhancing sound absorption and control of wave propagation due to sound speed differences. These factors reduce engine noise as well as lower gas temperature.

How much heat does a muffler remove?

About 90%!

In a well-designed muffler, most of the air from each cylinder exhaust cycle flows through a series of open channels, which are arranged between blowdown ports and outlets. The channels and ports provide a series of low-pressure zones, which allow the strong flow from the strong-blowdown ports to mix with the incoming air from the open channel. The channel/port arrangement acts as an effective heat sink, making it possible to draw large amounts of heat from each cylinder.

What is a muffler made out of?

Mufflers are typically built with a metal outer shell and a fiberglass or refractory lining inside.

The outer shell is typically made of steel or aluminum to provide a smooth surface for sound absorption.

The lining may be fiberglass or refractory material. These materials are impregnated with a fire-resistant material such as ceramic fiber, which helps slow the spread of fire.

Is a different type of muffler needed for racing?

This is a popular misconception. For road use, a muffler will improve your exhaust system’s effectiveness and lower its level of noise. If you’re going to be using your vehicle on the track, you should talk with a professional to get a custom-built racing exhaust system rather than simply change the muffler. A racetrack is an environment that requires different tradeoffs compared to street use.

What is the quietest muffler?

The quietest muffler is the one that muffles the most sound. This is determined by many factors, including the inner diameter of the pipe, what kind of baffling material is used, and whether any differences in pipe diameter exists between ports. The larger the difference between port diameters, the greater effect it will have on sound reduction.

What is the quietest muffler for a truck?

The quietest muffler for a truck is a good muffler, not a cheap one. The quietest truck mufflers are those that use the most amount of refractory (ceramic fiber) material. This is because most truckers like their trucks to sound like trucks. They like the deep, throaty rumble of the exhaust system. So you cannot buy the loudest muffler and expect it to be quiet; you must buy one designed for your specific kind of engine and exhaust system configuration.

What is the quietest muffler for a car?

The quietest muffler for a car is determined by the same factors as in trucks, but in an even more complicated fashion. Cars and trucks emit sound in different ways and in different places. Someone once said: “You can make a Harley Davidson sound like a Ferrari, but you can’t make a Ferrari engine sound like a Harley!” So it’s hard to say what the quietest muffler is for an automobile. The quietest muffler fits your car. You cannot buy the loudest one and expect it to be quiet; you must buy one that’s designed specifically for your vehicle.

Vibrant ultra quiet muffler?

Most people think of mufflers/resonators as being loud. Before buying one, you should know what kind of sound you are actually looking for. You can buy a muffler that is quite loud, but it will create more noise than you want. On the other hand, you can build one using less metal but have it be very quiet. Vibration at idle is not desirable even in a race car.

Even if your exhaust system produces very little noise at idle (and most cars do), vibration can still cause problems. At 60 to 75 MPH, engine vibration could cause the car to lift off the ground or vibrate excessively when the brakes are applied.

Whats the difference in putting a ultra quiet resonator in stock muffler?

In a stock muffler there is one resonator used two ways. The first is as a restriction to make the exhaust flow less turbulent inside the muffler plus to force it to slow down and then speed up again through the baffles. The second is that it acts as a resonator reflecting sound waves, away from your ears into the cabin of your car.

A ultra quiet resonator does all this but also acts as an additional baffle and it does not reflect sound waves into the cabin of your car. This greatly reduces obnoxious noise levels, making it ideal for those who don’t want so much noise in their cars, especially those with glasspacks or custom exhausts made from glasspacks.

The quietest muffler, or sound suppressor is the one that results in the least amount of sound being produced. The first step is choosing how loud you want your exhaust to be. If you want a louder vehicle, there are many mufflers on the market that will do just that. You can buy a cheap muffler or you can buy one that costs more money, but it will be more effective at reducing noise. After buying an effective muffler, if it’s still too loud for you, the next step would be to have it professionally installed by a reputable auto shop.