{{unreferenced, date=November 2018 A screamer pipe is a type of exhaust configuration fitted to some automotive

turbocharged In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

petrol engines with an external

wastegate A wastegate is a valve that controls the flow of exhaust gases to the turbine wheel in a turbocharged engine system.Robson, D. (2018). Aircraft General Knowledge. Aviation Theory Centre Pty Ltd. . Diversion of exhaust gases regulates the turbine ...

set-up, which vents the waste exhaust to the atmosphere through a separate un-muffled pipe, rather than back into the main exhaust track. This exhaust setup is known for its loud noise.

Principle of operation

To regulate the boost pressure on turbocharged engines a wastegate is fitted to allow exhaust gases to bypass the turbine and flow straight down the exhaust down-pipe. This can cause turbulent airflow around the turbine and high exhaust back pressure. To overcome this problem, gases can be re-routed down a separate pipe and vented straight to the atmosphere, resulting in improved performance.

Limitations

This configuration allows exhaust gases to flow straight to the atmosphere, therefore they do not pass through the

catalytic converter A catalytic converter is an exhaust emission control device that converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction. Catalytic converters are usually ...

exhaust silencer A muffler (North American and Australian English) or silencer (British English) is a device for reducing the noise emitted by the exhaust of an internal combustion engine—especially a noise-deadening device forming part of the exhaust sys ...

, which renders it illegal for street use in many countries owing to noise and exhaust emission regulations. Although exhaust emission laws do not apply away from the public highways in most countries, many race tracks have strict noise rules in place, once again outlawing screamer pipe use. Engine components