speaker near the tailpipe. The system generates sound wave 180 degrees out of phase with the engine noise. The sound waves from the electronic muffler collide with the exhaust sound waves and they cancel each other out, leaving only low-level heat to emerge form the tailpipe. 汽车生产商正在实验一种电子消声器，它使用传感器来检测排气噪音声波。声波信号被送到计算机，控制尾管附近的扬声器来产生一个与发动机噪音180度反相的声音。来自电子消声器的声波与排气噪音声波相撞，互相抵消，只将较少的能量由尾管排出。
6.3 The exhaust manifold, usually constructed of cast iron, is a pipe that conducts the exhaust gases from the combustion chambers to the exhaust pipe. It has smooth curves in it for improving the flow of exhaust.
排气歧管一般由铸铁做成，将废气由燃烧室送到排气管。排气歧管内有着光滑的表面，这是为了提高废气的流动。
The exhaust manifold is bolted to the cylinder head, and has entrances for the air that is injected into it. It is usually located under the intake manifold.
排气歧管使用螺栓连接在气缸盖上，有着供空气喷入的通道。它同样位于进气歧管的下面。 A header is a different type of manifold, it is made of separate equal-length tubes. 集气管是另一种形式的歧管，它由许多独立等长的管道组成。
6.4 There are several types of gaskets that connects the exhaust pipe to the manifold.
有几种类型连接排气管和歧管的垫圈。
One is a flat surface gasket. Another type uses a ball and socket with springs to maintain pressure. This type allows some flexibility without breakage of the seal or the manifold. A third type is the full ball connector type, which also allows a little flexibility.
一种是平面垫圈。另一种使用球铰式垫圈，使用弹簧来保持压力，它可以在不破坏密封和歧管的条件下允许产生一定的变形。第三种是全球式接头垫圈，它也允许产生少量的变形。 6.5 Hangers hold the exhaust system in place. They give the system flexibility and reduce the noise level. The hanger system consists of rubber rings, tubes and clamps.
排气管吊耳将排气系统固定住，并且使得排气系统有一定的灵活性和减小噪音级别。吊耳系统由橡胶圈，管子和夹具组成。
6.6 The exhaust pipe is the bent-up or convoluted pipes underneath a car. Some are shaped to go over the rear axle, allowing the rear axle to move up and down without bumping into the exhaust pipe, some are shaped to bend around under the floor of the car, connecting the catalytic converter with the muffler. Exhaust pipes are usually made out of stainless steel, since the high heat conditions involved with the muffler system will cause rust.
排气管弯曲盘旋于汽车底部。一些排气管布置在后轴上，这样后轴上下跳动就不会撞击到排气管，一些盘旋弯曲于汽车底盘上，连接催化转换器和消声器。由于消声器的高温环境容易产生锈，所以排气管一般采用不锈钢做成。
6.7 The advantage of a dual exhaust system is that the engine exhausts more freely, thereby lowering the backpressure, which is inherent in an exhaust system. With a dual system, a sizable increase in engine horsepower can be obtained because the breathing capacity of the engine is improved, leaving less exhaust gases in the engines at the end of each exhaust stroke. This, in turn, leaves more room for an extra intake of the air-fuel mixture. 双排气系统的优势就是发动机能够更自由地排气，因此可以降低排气系统固有的背压。装有双排气系统的发动机可以获得相当大的功率提升，这是因为发动机进气的能力得到了改善。每次排气冲程末端，更少的废气被留在发动机内，从而给发动机吸入可燃混和气留下更多的空间。
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1 Carbon monoxide (CO) also increases the rate at which the photochemical smog is formed by speeding up the conversion of nitric oxide (NO) to nitrogen dioxide. 一氧化碳也增加了光化学烟雾形成的几率。因为一氧化碳促进了一氧化氮向二氧化氮的转变。 2 Oxide of sulfur were initially ignored in the exhaust system, since the sulfur content of gasoline as a fuel is less than 1/10 of 1 percent. Because of this small amount, it was felt that it contributed very little to the overall pollution problem. However, the automobile exhaust system, when equipped with a catalytic converter, changes the sulfur dioxide into sulfur trioxide. When this combines with water vapors, a sulfuric acid mist is formed and is a very difficult pollutant to handle since it is extremely corrosive.
排气系统中的硫氧化合物之前是被忽视的，因为汽油作为燃料，硫的比例小于千分之一。由于这么低的含量，它曾经被认为总污染造成不了多大的影响。但是，装有转换器的排放系统将二氧化硫转换为三氧化硫。当它与水蒸汽混合，就形成了硫酸酸雾。这是非常难于解决的污染物，因为它有强烈的腐蚀性。
3 By visually inspecting the tailpipe emission, a determination can be make as to where an engine to defect may exist. An engine with light gray or blue smoke emitting from the tailpipe normally indicates an increase in the oil consumption through burning due to internal engine wear. Black smoke would indicate a defective fuel delivery system, causing the engine to operate in a rich mode.
通过肉眼观察排气管的排放，可以判断发动机哪里存在问题。发动机排气管排出白色或蓝色烟雾通常表示由于发动机损耗使得耗油量增加。黑色烟雾意味着燃油喷射系统可能存在问题，从而使得发动机运行在浓的工况下。
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