A muffler or silencer is an integral part of your car's exhaust system. For an engine to run, fuel and air are burned in the combustion chamber. This process creates a number of emissions, including carbon monoxide, nitrogen oxide, and nitrogen monoxide, which must be removed by the exhaust system in order for the car to be safe for passengers and the environment. In addition to this basic function, the right exhaust system allows your car to run with the greatest fuel efficiency and the system silences the loud noises caused by combustion. Mufflers and silencers are the same thing, but the former is a name more commonly found in North America. As the name suggests, the silencer is the part of the exhaust system that quiets the noise caused by combustion.
Finding the right mufflers/silencers for your car requires a bit of research. Understand how the exhaust system fits together and what types of exhausts and silencers are available to make it easier to find the right one for the job. Learn how performance and fuel efficiency are affected by the type of silencers that you choose. Finally, learn how to shop for mufflers or silencers. Silencers are available from garages, specialist dealers, and online from eBay..
How Does an Exhaust System Fit Together?
An exhaust system can be described as a series of pipes and chambers that run from the engine to the back or side of the car. In modern cars a typical exhaust system is made up of a number of parts, including the exhaust manifold, oxygen sensor, and catalytic converter.
The exhaust manifold is attached to the engine at the cylinder head and vents the gases from the cylinders into a single pipe. In addition, it burns the excess fuel that has not been burned by the engine.
An oxygen sensor is situated in or near the manifold and sends oxygen level readings to the car's computer. This allows the computer to determine how much fuel the engine needs for optimum efficiency.
Next in line is the catalytic converter,, which turns harmful gases into carbon dioxide and water vapour. This protects the environment from more toxic emissions. All the components after this are referred to as the cat-back exhaust system and are at the back of the catalytic converter. The silencer is usually located in this section and consists of a metal box that contains a series of tubes, known as baffles, that the sound waves created by the combustion process must travel through. The baffles cause the waves to lose energy, making them quieter as they move.
The resonator is situated at the back of the silencer and cancels sound waves through a build up of pressure. Some silencers use materials like fibreglass to absorb sound waves, and others use both methods. Exhaust pipes run throughout the system, carrying exhaust gases from the manifold to the tailpipe and all the components in between.
While most cars have a single exhaust system, those with eight cylinder engines may have two. One is used for the right cylinders and one for the left. Where a dual exhaust system is used, both should run efficiently to ensure that the car performs the way that it ought to.
Types of Exhaust Silencers
Silencers are categorised according to their overall design and how they work to dampen sound. Although there are various types of silencers, the three main types are multiple baffle, turbo, and straight through silencers.
Multiple Baffle Silencers
Multiple baffle silencers house a number of baffles inside a metal enclosure. Exhaust gas escapes through the holes punched in the walls of the silencer tube, muffling the sound through pulse reflection. These silencers are considered to be fairly restrictive.
Turbo silencers do not contain baffles, but are made with an S-shaped path inside. This allows gas to enter the silencer before being forced out into a tube that exits the exhaust system. Turbo silencers are also considered restrictive, with poor gas flow, but their design allows them to be longer on the inside than the outside.
Most modern silencers follow the straight-through design, which involves the use of a perforated tube. Gas is forced from the silencer's inlet to the outlet, with little flow restriction. The holes in the pipe allow the gas to expand silently. Some systems have more than one chamber.
Performance silencers change the way that your car sounds, using their resonating chamber to amplify and tune the exhaust note. These silencers often yield a deeper, more aggressive sound than standard mufflers.
Silencers come with a range of inlets. The type that you need depends on your existing exhaust system. If it is the standard system that was fitted to the car when it was produced, check the owner's manual for the car for details. If the car has an exhaust system as a spare part, research the make and model or consult your mechanic for information about the inlet type required.
Materials Used to Make Mufflers/Silencers
Two types of metal are used to create exhaust systems and silencers: mild steel and stainless steel.. As these components are prone to damage caused by rust, stainless steel is the most durable option. It is also the most expensive, but systems and components come with a lifetime guarantee. Mild steel tends to last no more than three years, especially near the coast where salty air promotes corrosion. Choosing coated mild steel, which has been painted with corrosion retardant paint, can prolong the life of cheaper silencers. For your car to pass its annual Ministry of Transport (MOT) test, the exhaust system must have no leaks, so investing in a good quality silencer may save money in the long run.
Car Performance vs. Fuel Economy
Before shopping for a new silencer, decide whether you want better vehicle performance or greater fuel economy. Higher exhaust flow through the silencer improves speed and vehicle performance, but decreases fuel economy. The standard system that was fitted to your car when it was manufactured may not yield the best performance, but chances are that this system produces the best fuel economy.
Finding the Right Silencer for Your Car
If you decide on a standard silencer that fits the car's existing exhaust system, check the owner's manual for the car for details about the type of silencer that you need. If you do not have access to the manual, then contact the manufacturer or a local dealer for more information. Alternatively, ask for advice from your mechanic or from an exhaust centre.
If you would like to fit a spare part silencer for improved performance, then research the types of silencers available that would complement your car and give it the right type of performance boost. If you are still unsure of the right silencer or muffler, ask your mechanic for advice. The type of silencer that you need may be fairly specific to your exhaust system.
Buying Mufflers/Silencers on eBay
Shopping on eBay is easy if you know how to search effectively. When buying car parts and accessories, always have your car's make, model, and year on hand. To search for a muffler/silencer, type a search phrase, such as "Ford Escort rear silencer&", in the box, which is shown on every page, to see the items available from eBay sellers. Refine your search by choosing the right category and the desired item features. To expand or narrow your search, use the advanced search function..
Evaluating the Item and the Seller
Before buying on eBay, take a moment to learn about the item and the seller. All of the information that you need to do this can be found on the item listing page,, which is accessed by clicking on an individual listing. Look here for details such as the full item description, buying options, payment methods, postage and packaging costs, and the seller's feedback information. When buying larger items, look for local sellers who allow collection to save on postage and packaging costs. eBay's seller feedback feature lets you see what other buyers think of a particular seller's products and customer service.
Buying the right mufflers/silencers can seem tricky, but understanding how these components work and how they fit into the exhaust system gives you a better idea of what you are looking for while you shop. The exhaust system's main function is to carry toxic exhaust gases away from the engine, releasing them in one place, which is usually at the back or side of the car. A catalytic converter removes some of the toxic elements, while a silencer dissipates the noise created by the combustion process.
Silencers work in different ways depending on the way they are constructed, allowing sound waves to lose some power before they are released, or through materials used to absorb some of the sound waves. Some silencers use both of these methods to control noise. Performance silencers amplify and tune certain types of engine noise, yielding a deeper, more aggressive sound.
The silencer determines how much fuel is allowed through the exhaust system. Increased flow leads to better performance at the cost of fuel economy and vice versa. If you are unsure of the options available for your car and your needs, then check the owner's manual for the car, consult your mechanic, or research the type of silencer that you are considering. eBay sellers offer a range of silencers, from standard to performance models, at competitive prices.