Silences the exhaust, and neutralizes the hot gases
Did you ever wonder how the exhaust system works? Let me explain it to you.
The components of the exhaust system consist of:
- Catalytic converter
- Exhaust manifold
- Helmholtz tuning chambers
- Oxygen sensor
The exhaust system is designed not only to silence the sound of the exhaust, but also to neutralize the hot poisonous gases produced by the engine.
The EXHAUST MANIFOLD reduces combustion noise and transfers heat downstream to promote the continued oxidation of unburned hydrocarbons and carbon monoxide. The exhaust manifold thereby supplies some emissions control before the exhaust reaches the CATALYTIC CONVERTER fitted further downstream.
Engine noise is a jumbled collection of firing frequencies, which range from about 100 to 400 hertz, (1 hertz=1 cycle per second), overtones of these, and an extended range of noise caused by resonance of various components. The MUFFLER silences the exhaust by channeling the exhaust through compartments called HEMHOLTZ TUNING CHAMBERS. These chambers are set up to cancel resonance of specific frequencies. Other chambers are designed to reduce the energy pulses and thus attenuate a wide range of frequencies. When the exhaust gases finally pass out the tail pipe, their temperature, pressure, and noise has been significantly reduced.
The catalytic converter is a device that is designed to create a chemical reaction of the exhaust gasses. The exhaust gasses contain carbon monoxide, nitrogen oxide and hydrocarbons. The catalytic converter contains platinum and palladium in a honeycomb structure. The exhaust gasses contact these catalysts as they pass through this structure turning the gasses into harmless carbon dioxide and water vapor. In cars with catalytic converters, lead-free gasoline must be used in order to prevent coating the catalysts with lead, rendering them ineffective.
The OXYGEN SENSOR detects the content of oxygen in the exhaust stream. By detecting the amount of oxygen in the exhaust, the sensor tells the electronic control unit how much to vary the fuel/air ratio for a particular instant. Since the RPM, engine temperature, coolant temperature, air temperature, and other variables change constantly, the oxygen sensor is an important component to maintain optimum efficiency and performance.