Exhaust system-Mufflers

Mufflers It's amazing what a difference a muffler can make to reducing the noise levels of an exhaust system. Exhaust gases leave the engine under extremely high pressure. If these gases escaped directly from the engine the noise would be tremendous. For this reason, the exhaust manifold sends the gases to a muffler where they go through metal plates, or tubes, with a series of holes. The pressure of the gases is reduced when they pass through the muffler, so they go out of the tail pipe quietly.


There are two main types of muffler design. One type uses several baffled chambers to reduce noise. The other type sends the gases straight through perforated pipe wrapped in metal or fiberglass. This type of muffler is designed for the purpose of reducing back pressure and, consequently, makes slightly more noise. Some exhaust systems also have a resonator. They are added at the end of the exhaust system to take care of any noise that has made it through the muffler.


While the goal is to absorb energy that would otherwise be released as sound into the environment, mufflers do force engines to work somewhat harder pushing exhaust gas through them. Therefore, it is a common engine tuning practice to replace stock mufflers with versions that require less energy to force the gas through (usually described as lowering the "back pressure"). Such accessory mufflers can often increase a vehicle's power, but usually at the cost of less effective noise suppression.