Muffler
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This article may require cleanup to meet Wikipedia's quality standards. Please improve this article if you can. (July 2007) |
A muffler (or silencer in British English) is a device for reducing the amount of noise emitted by a machine. On internal combustion engines, the engine exhaust blows out through the muffler. The internal combustion engine muffler or silencer was developed in parallel with the firearm suppressor by Hiram Percy Maxim. [1]
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[edit] Description
Mufflers are typically installed along the exhaust pipe as part of the exhaust system of an internal combustion engine (of a vehicle, or stationary) to reduce its exhaust noise. The muffler accomplishes this with a resonating chamber, which is specifically tuned to cause destructive interference, where opposite sound waves cancel each other out.
Catalytic converters also often have a muffling effect. The effect is mainly generated largely by restriction, rather than by cancellation.
[edit] Advantages
Mufflers that reduced backpressure relative to earlier models became increasingly available in the late 20th century, and resulted in increased engine efficiency, performance, power output, and simultaneously decreased overall wear and tear on the engines' components, as well as sound to levels in compliance with the law.
[edit] Mini-mufflers
A mini-muffler (also known as a "hotdog" in the auto industry) can be put in place of a normal muffler in a car exhaust system to "enhance" the sound of the exhaust for a car enthusiast. These are smaller, cost usually about half the price of a normal muffler and work in a similar way, but allowing more sound through. By using a specific muffler / mini-muffler / catalytic converter combination, the sound of a car's exhaust system can be changed considerably. Any removal of a muffler from a "factory" setup will of course risk the resulting noise being over government approved noise levels and may attract unwanted attention from the law.
[edit] Types and positions of mufflers
- With cars, lengthwise underneath, blowing backwards at the rear
- to the sides before the rear wheels.
- With large diesel-powered trucks:-
- Mounted vertically behind the cab
- Crosswise under the front of the cab, blowing sideways.
- With motorcycles:
- Usually, beside the engine and rear wheel blowing backwards.
- In more modern motorcycles, under the seat blowing backwards from under the back of the seat. (Under-slung)
- Under-engine exhausts first reached popularity with Buell motorcycles, though by 2008 most manufactures began using the under-engine design as well.
Motorcycle enthusiasts sometimes use the term "raygun," "drag pipes" or "pea-shooter" for the old shape of motorcycle exhaust silencer/muffler with a long straight cylindrical barrel that merged roundedly at each end into the pipe, as in this image and this image.
