Engine Anatomy – 5 Key Components of a Turbocharged Engine and How They Work

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Two words will put the biggest grin on any automotive enthusiast’s face – turbocharged engine. They’re fast, they’re loud, and they’re in demand. What could be better? A turbocharger is a device that increases your engine’s power output and efficiency. You may know what one is, but do you know what it’s made of? Read on to learn about the critical components of a turbocharged engine and how they work. 

The Blow Off Valve

You might hear your car-mad friends talking about blow off valves and wonder what they’re talking about. A blow off valve is a key component in a turbocharged engine, designed to take the load off the turbocharger when the throttle closes. The air pressure is then re-circulated into the end of the intake which otherwise has no pressure. 

The Radial/Axial Inflow Turbine

If you’re looking for balance in your turbocharger’s efficiency, response, and performance, then pay close attention to the turbine. The turbines in turbocharged engines are either radial or axial inflow units. Most commonly, they are radial, but large diesel engines can operate with axial inflow turbines. 

Their job is to direct gas flow while spinning at up to 250,000 RPM. The size and shape of a turbine will determine its performance. A larger one can take more pressure and heat to spin the turbine, which creates a low-speed lag. However, even if a small turbocharger spins quickly, it can lack a high acceleration speed. 

The Compressor

The compressor in a turbocharged engine consists of volute housing with a diffuser and impeller. Its job is to increase the mass of intake air that enters the combustion chamber. The range of your compressor is often determined by the compressor map, which is a chart predicted by a computer program. While the job of the compressor might seem small, it can make or break your turbocharged engine’s performance and efficiency. 

The Center Housing Rotating Assembly

Most people with turbocharged engines and a knack for all things automotive will understand just how vital the compressor impeller and turbine are. Equally as important is what houses them, and that’s the center housing rotating assembly (CHRA). This component houses the shaft that connects to those components, and it also has a bearing system. 

The bearing system suspends the shaft and lets it rotate with minimal friction at high speeds. In cars, the CHRA has ball bearings or thrust bearings. The ball bearings are lubricated with pressurized engine oil. Sometimes, the CHRA is also water-cooled with entry and exit points for the engine coolant. 

With all these components operating at their best, drivers can enjoy a turbocharger that has increased acceleration and reduced turbo lag. 


The wastegate is not something that appears in all turbocharged engines. Still, it’s definitely an advanced piece of technology that’s worth your inspection. The wastegate’s job is to regulate the exhaust gas flow that enters through the driving turbine on the exhaust side. By doing this, it also controls the air intake into the manifold. 

A turbocharged engine is a complicated beast, but it’s one that can add much fun and value to your passion and hobbies. If you’ve been thinking about building a turbo engine or buying one already made, then why not ask about these five components above? You may be surprised to learn just how valuable a blow-off valve, compressor, and even a turbine, really are.

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