Updated: Jan 8
An exhaust configuration called a screamer pipe is designed for use with turbocharged petrol engines that have an external wastegate. These are also known as divorced wastegate dumps or dumper pipes.
Instead of routing exhaust gas back into the main exhaust pipe, a screamer pipe vents exhaust directly into the atmosphere through a separate, un-muffled pipe. This exhaust setup is characterised by its loud, distinctive noise.
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What Is a Screamer Pipe?
A screamer pipe is a type of exhaust configuration that is typically fitted to automotive turbocharged petrol engines with an external wastegate setup.
The primary purpose of an exhaust system is to route the engine's exhaust gases away from the vehicle and release them into the atmosphere.
However, the exhaust gases may contain unburnt fuel or other harmful emissions that need to be processed by a catalytic converter or silencer before they can be released into the environment.
This type of atmospheric wastegate dumper pipe bypasses this process by venting the exhaust gases directly to the atmosphere through a separate, un-muffled pipe. This exhaust configuration is known for its loud, distinctive noise, which is why it is often referred to as a "screamer pipe".
While this type of exhaust setup may be popular with some drivers for its unique sound, it is generally considered illegal for street use in many countries due to noise and exhaust emission regulations.
Benefits of a Screamer Pipe Exhaust
May slightly increase power by reducing back pressure in the exhaust system.
Produces a loud, distinctive noise that may be attractive to some drivers.
Drawbacks of a Screamer Pipe Exhaust
Generally considered illegal for street use due to noise and exhaust emission regulations.
May contribute to air pollution and not be environmentally friendly.
May void the vehicle's emission control system warranty.
Potential power increase is likely to be minimal, and the use of a screamer pipe may actually decrease the overall performance of the vehicle.
May be a nuisance to others and violate local noise ordinances.
Do Screamer Pipes Add Power?
It is possible that a screamer pipe may slightly increase the power of a vehicle by reducing back pressure in the exhaust system. Back pressure is the resistance that the exhaust gases encounter as they pass through the exhaust pipes and mufflers.
By venting the exhaust gases directly to the atmosphere through a separate, un-muffled pipe, a screamer pipe may help to reduce back pressure and allow the engine to more easily expel exhaust gases. This can potentially lead to a small increase in power.
Is a Screamer Pipe Legal?
The screamer pipe configuration bypasses the catalytic converter and exhaust silencer, allowing exhaust gases to flow directly into the atmosphere. As a result, it is often illegal to use on public roads in many countries due to noise and exhaust emission regulations.
Even in areas where exhaust emission laws do not apply to non-public roads, many race tracks have strict noise rules that prohibit the use of screamer pipes.