A screamer pipe is a kind of exhaust design that vents waste exhaust to the atmosphere via a separate unmuffled pipe rather than back into the main exhaust track.
You can only install this exhaust system on a turbocharged engine with an external wastegate. It is well-known for producing a lot of noise at full-throttle, hence its name.
There are a few distinct benefits and drawbacks of a screamer pipe, as explained below.
What Is a Screamer Pipe?
A screamer pipe is an exhaust configuration that tuners may fit to a very highly-tuned car.
It essentially routes exhaust gas from the wastegate through an unmuffled pipe separated from the main exhaust.
Cars fitted with a screamer pipe have a unique sound, some describe it as though the engine is “screaming”, hence the name screamer pipe.
On turbocharged engines, a wastegate (usually an internal wastegate) is installed to enable exhaust gases to skip the turbine and flow directly down the exhaust down-pipe, thus regulating boost pressure.
If the boost pressure was unregulated, you would see a lot more blown engines due to over-boost and much higher power figures.
However, a consequence of wastegates is turbulent airflow around the turbine, this can cause increased back pressure, reducing performance and power potential.
Many tuners have found a way to get around this issue, they install a screamer pipe which diverts exhaust gases via a separate pipe and released directly to the atmosphere, which results in increased performance and tuning potential.
They can be installed anywhere, but most commonly they come through the bonnet, out of the side or under the car facing the ground.
Screamer pipes usually require the usage of an external wastegate.
Further Reading: Wastegate Types: Internal vs External
Benefits of a Screamer Pipe Exhaust
The benefits of a screamer pipe are mostly due its lessened exhaust restriction and reduced turbulence on the turbine.
The benefits of a screamer pipe exhaust system are listed below.
- Improved performance & tuning potential
- Enhanced full-throttle sound
- Faster turbo spool & response
- Less pipework for an external wastegate
1. Improved Performance & Tuning Potential
Due to a screamer pipe reducing exhaust back pressure, restriction and turbulence, performance and power is improved.
When tuning a car with a screamer pipe, there will be increased potential for power.
2. Enhanced Full-Throttle Sound
The unique benefit (for some people) of a screamer pipe is that they can dramatically enhance exhaust sound, but only when at full-throttle.
Because the screamer pipe is unmuffled and comes straight from the turbocharger, the sound is very loud, but only when the wastegate is open.
An external wastegate usually only opens fully when at full-throttle, watching the video below you’ll notice how the exhaust sound gets much more aggressive and loud only when at full-throttle.
3. Faster Turbo Spool & Response
Due to less turbulence and restriction, the exhaust and turbine are much more free flowing.
This improved exhaust flow can cause the turbo to spool faster and more quickly than a stock vehicle.
Therefore, improving throttle response.
4. Less Pipework for an External Wastegate
When installing an external wastegate, you have two options for exhaust pipework.
You can either route the wastegate pipe back into the main exhaust or route the pipe straight to atmosphere, known as a screamer pipe.
This is another reason why thy are often used in high-performance tuner cars.
Screamer Pipe Drawbacks
There are also several disadvantages for the usage of a screamer pipe, surrounding their legality and noise.
Legality & Usage
A screamer pipe is prohibited on the road in many countries due to noise and exhaust emission laws since it enables exhaust gases to escape directly into the atmosphere and thus do not pass through the catalytic converter or exhaust silencer.
Despite the fact that exhaust emission regulations do not apply away from public roads in the majority of nations, many racing courses have stringent noise regulations in place, which once again prohibit the usage of screamer pipes.
Noise
As mentioned above, a screamer pipe is almost always unmuffled and therefore it is very loud.
Due to noise and exhaust decibel laws in most countries, regardless of emissions, it is illegal to use this exhaust setup.
Also, some people view the noise generated by a screamer pipe as a disadvantage.
Should You Fit A Screamer Pipe Exhaust?
Fitting a screamer pipe usually requires the installation of an external wastegate, which is expensive and requires extensive tuning to properly setup.
A screamer pipe also usually requires some custom pipework and welding, which can also become expensive.
Besides the steep installation costs, it is almost always illegal to drive a car on public roads with this exhaust configuration, due to emission and noise laws.
Even if you’re using the car for track days or racing, it is likely prohibited by the decibel limits of most race tracks.
Therefore, it is not recommended to install a screamer pipe setup.
Are They Legal?
No they are not legal; in fact, they’re almost always illegal to use on public roads due to various reasons.
They are illegal due to emission and noise laws, because the exhaust gases come straight from the turbo to the atmosphere, they don’t pass through a catalytic converter or silencer.
Current exhaust noise limits in the United Kingdom are 74 decibels (74 db), which is considerably lower than the noise limits in most states in the United States.
For the reasons mentioned above, screamer pipes are almost always illegal.
Conclusion
Installing a screamer pipe is not recommended and there are not many places you can legally drive a vehicle with one installed.
The benefits are improved power, response and tuning potential.
Screamer pipes are also very loud and have a unique sound to them, some see this as an advantage and some as a disadvantage.
