Exhaust manifold on a car engine Muffler and tailpipe on a car
The exhaust system is typically a conduit for directing the reaction exhaust gases away from controlled combustion within the engine or furnace. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes. Depending on the overall system design, exhaust gas can flow through one or more of the following:
• Cylinder head and exhaust manifold
• A turbocharger to increase engine power.
• A catalytic converter to reduce air pollution.
• A muffler (North America) / silencer (UK/India), to reduce noise.
Exaust system tuning
Aftermarket exhaust system including headers and a white plasma-sprayed ceramic coating
Many automotive companies offer aftermarket exhaust system upgrades as a sub-category of engine tuning. This is usually quite expensive as it typically involves replacing the entire exhaust manifold or other large components. However, these upgrades can significantly improve engine performance and and do this through means of two main principles:
By reducing the exhaust back pressure, engine power is increased in four-stroke engines
By reducing the amount of heat from the exhaust being lost into the underbonnet area. This reduces the under-net temperature and thus the intake manifold temperature, thereby increasing power. This also has positive side effect of preventing the heat sensitive element. In addition, maintaining heat in the exhaust gas accelerates this heat, thereby reducing back pressure as well.
Back pressure is most commonly reduced by replacing exhaust manifolds with headers, which have smoother bends and normally wider pipe diameters.
Exhaust heat management helps to reduce the amount of waste heat radiated from the exhaust pipe and components. One major solution for aftermarket retrofits is to use a ceramic coating applied by thermal spraying. This not only reduces heat loss and reduces back pressure, but also provides an effective way to protect the exhaust system from wear and tear, thermal degradation and corrosion.