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What Is a Turbo Wastegate (Full Guide)

Updated: Jan 8

A wastegate is an exhaust bypass valve that is used to regulate the flow of exhaust gases in a turbocharged engine. It is an important component that helps to control boost pressure and prevent the turbo from over-speeding.


In this article, we will delve into the details of what a wastegate is, whether you need one on a turbocharged engine, and where it is located on a turbo.

 

Table of Contents:


an inside view of a internal wastegate on a turbocharger

What Is a Wastegate?

A wastegate is a valve that is mounted on the exhaust side of a turbocharger. It is used to regulate the flow of exhaust gases that pass through the turbo, which in turn helps to control boost pressure.


Boost pressure is the amount of extra air that is forced into the engine by the turbo, and it is an important factor in determining engine performance.


The wastegate consists of a valve that is actuated by a diaphragm or a spring. When the boost pressure reaches a certain level, the wastegate opens and allows some of the exhaust gases to bypass the turbine, reducing the amount of boost pressure being generated.


This helps to prevent the turbo from over-speeding and damaging itself.


> Read more about how a wastegate works here


Do You Need a Wastegate on a Turbo?

Yes, you need a wastegate on a turbocharged engine. The wastegate is an important component that helps to regulate boost pressure and prevent the turbo from over-speeding.


Without a wastegate, the turbo could potentially over-speed and suffer damage, which could lead to costly repairs or even engine failure.


Where Is the Wastegate on a Turbo?

The wastegate is usually located on the exhaust side of the turbocharger. It is typically mounted to the exhaust manifold or the downpipe, and it is connected to the turbo via a pipe or hose.


The location of the wastegate can vary depending on the specific design of the turbo and the engine, but it is typically found in close proximity to the turbo.


Types of Turbo Wastegates

Turbo wastegates are valves that are used to control the amount of boost produced by the turbocharger in an internal combustion engine. There are two main types of turbo wastegates; internal wastegates and external wastegates.


An internal wastegate is built into the turbocharger and is commonly found in smaller, less powerful engines, while an external wastegate is separate from the turbocharger and typically used in larger, more powerful engines.


Both types have their own advantages and disadvantages, and the appropriate type will depend on the specific needs and requirements of the vehicle and its engine.


Internal Wastegate

Internal wastegates are built into the turbocharger itself and are commonly found in smaller, less powerful engines. They are typically easier to install and require less maintenance than external wastegates.


However, they may not offer as much precision and control as external wastegates, and may not be able to handle the increased boost levels needed for high-performance applications.


internal wastegate diagram

External Wastegate

External wastegates, on the other hand, are separate from the turbocharger and are usually found in larger, more powerful engines. They offer more precise control of boost levels and are better able to handle the increased boost levels needed for high-performance applications.


However, they are typically more complex to install and require more maintenance than internal wastegates.



Screamer Pipe (Atmospheric/Divorced Wastegates)

A screamer pipe, also known as a wastegate dump pipe, is a type of exhaust configuration that is often used on automotive turbocharged petrol engines with external wastegate setups.


The primary function of an exhaust system is to direct the engine's exhaust gases away from the vehicle and release them into the atmosphere.


However, these gases may contain harmful substances such as unburnt