How Does A Turbocharger Work

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2020 Toyota Supra
Jonathon Klein

There was a time when the V8 reigned supreme. When “There’s no replacement for displacement!” was affixed to every chromed-out muscle car’s bumper. As Bob Dylan once said, though, “The times, they are a-changin’” and in the automotive world, that change brings turbochargers.

A turbocharger is a system that helps an engine produce more power and torque through forced induction. Essentially, a turbo sucks in air, chills it, and then force-feeds the engine more air than what it would get through its standard intake. The end result is a lot more “Whee!”

Yet, turbochargers can be mysterious and their inner workings can seem impregnable to fully understand. They don’t have to be. With The Drive’s crack informational team by your side, we’ll get you from squinting at your engine and wrongly pointing to the starter to overnight parts from Japan...or Austria.

Ready? Steady? Go!

A turbocharger with wastegate.
Depositphotos

A turbocharger!

What Is a Turbocharger?

A turbocharger is a small turbine that sits between the engine and the exhaust. Plumbed to both, as well as the car’s air intake, a turbocharger uses the exhaust gases to spin the turbine which then forces more air into your car’s engine and increases the car’s power. There are four parts that allow a turbocharger to work. They are:

Turbocharger

The turbocharger itself resembles a snail and features an air intake, an exhaust intake, two different impellers (a turbine in the rear and compressor toward the front), and a charged air exhaust that goes to the intercooler. There’s also a hose line for oil. 

Intercooler

To reduce the temperature of the charged air forced out of the turbocharger, a secondary radiator, or intercooler, intercepts the air before it reaches the engine. It uses coolant as a chilling agent. 

Wastegate

A wastegate is a valve in between the exhaust intake and the turbocharger that bypasses the turbine to control the boost pressure.  

ECU Tune

A turbocharged engine’s electronic brain needs different calibration for fuel-to-air mixtures and ignition timing, compared to a car with a naturally aspirated engine. As such, if someone adds a turbocharger to an engine that was never meant for one, they’d have to reprogram the engine’s electronic control unit (ECU) in order for it to function properly. 

A twin-turbocharged McLaren 720S on El Mirage's dry lakebed.
Jonathon Klein

A twin-turbocharged McLaren 720S. 

Types of Turbochargers

There’s a great variety of turbochargers and turbocharged applications. Here’s a rundown of common setups.

Single Turbocharger

A single turbocharger is the most common type of turbocharged setup. It features a single turbine, and in the mainstream consumer market, it is generally used in more pedestrian cars that don’t need a lot of horsepower or torque. In the aftermarket, it’s one of the most popular tuner upgrades.

An example of this would be the Honda Civic.

Twin-Turbocharged

Adding a second turbocharger increases the amount of air that can be forced into the engine to create more robust power and torque. The setup remains generally the same as a single turbo system, unless you have a stepped twin-turbocharger system that pairs a small turbo with a large turbo to eliminate lag.

An example of this would be a McLaren 570S

Quad-Turbocharged

The Bugatti Chiron is the only production car that uses a quad-turbocharged setup. Bugatti mates two large turbos and two small turbos to an 8.0-liter W16 engine to produce a total of 1,500 horsepower. According to the man who took it to 304 mph, it’s a rush

Compound Charged

A compound charged system is when a turbocharger is paired with a supercharger. The supercharger is used to generate more immediate torque, while the turbocharger extends the amount of top-end horsepower. 

An example of this would be Volvo’s compound charged four-cylinder which is used in the T6-grade cars and SUVs. 

A diagram of an e-Turbocharger.
Audi

A diagram of an e-Turbocharger.

E-Turbocharger

The concept of an e-turbocharger has been floated for some time, but it took the might and billion-dollar research and development of Formula 1 to engineer a production-worthy product. 

With a design taken from the current crop of Formula 1 cars, an e-turbocharger adds electricity to the mix in order to eliminate turbo lag. A small electric motor is placed between the turbine housing and the compressor and runs off a 48V electrical system. The electric motor can spin the compressor before the exhaust gases can, thus eliminating the time between no boost and boost. 

Audi states that the addition of the electric motor on its unit “reduces [the turbocharger’s] response time to less than 250 milliseconds, faster than an average human’s reaction time.”

Along with Audi, Mercedes-Benz is also coming out with e-turbocharged cars. 

Hot-V Turbocharger

A “Hot-V” setup is when the turbocharger or turbochargers are placed inside the “V” of an engine. This not only reduces the space needed for an engine but also reduces the distance the charged air needs to travel between the compressor and the engine. That means the turbocharger or turbochargers can spool quicker and reduce lag. 

A “Hot-V” setup also separates the turbine and compressor and puts them on opposite sides of the engine. This reduces heat build-up in the then-charged air and significantly reduces the intercoolers’ cooling load. 

Mercedes-Benz was the first automaker to put the “Hot-V” setup into production. 

A turbocharged Hyundai Veloster N.
Jonathon Klein

A turbocharged Hyundai Veloster N. 

Who Invented the Turbocharger?

A Swiss engineer named Alfred Buchi first came up with the turbocharger design to boost power in diesel engines in 1905. Neat!

How Much Extra Power Can You Get?

This is every gearhead’s question, and unfortunately, there’s no easy answer. Common turbocharger gains net enthusiasts about 20-40 percent more power than stock.

However, how much extra power depends on a host of variables, including how large or small the turbocharger is, what modifications you’ve done to the engine’s internals, what type of fuel you’re using, and the ECU tune your turbocharger setup uses. Your car’s gains will vary. 

Advantages and Disadvantages of Turbochargers

Everything has its tradeoffs, and turbochargers aren’t any different. Here are a few of the advantages and disadvantages of turbochargers. 

Advantages

Due to the increased airflow, a turbocharger will add more power and torque to an engine’s performance. At the same time, because turbochargers can make a lot of power, manufacturers can downsize engine displacement and thus receive better efficiency and better emissions.

Disadvantages

There are disadvantages, though, such as increased complexity, which makes a turbocharged engine expensive to repair. There’s also the issue of turbo lag.

What Is Turbo Lag?

One of the biggest issues with turbocharger performance is turbo lag. As turbochargers require the exhaust gases to spool the turbine and thus the compressor, it takes time to build boost and force more air into the engine. The effect feels as if there’s a momentary pause between when you hit the throttle and you feel the power surge. This is why manufacturers have begun experimenting with e-turbochargers. 

A supercharged Shelby Mustang GT500.
Jonathon Klein

A supercharged Shelby Mustang GT500. 

FAQs About Turbochargers

You’ve got questions about turbochargers, The Drive’s informational team has answers.

How is a Supercharger Different?

While a turbocharger uses exhaust gases to propel the turbine that forces more air into the engine, a supercharger uses the motor’s belt system to turn a turbine that forces more air into the engine. Because it’s being run off the engine’s own power, superchargers tend to be less efficient both in making boost and in fuel economy compared to a turbocharger. 

Does My Car Have a Turbocharger?

Maybe. There are a few ways of checking. The first and easiest is thumbing through your car’s dusty manual. The second is looking it up online, either on the manufacturer’s website or Google. The last way is to visually inspect the engine. If there’s a cylindrical snail-like metal part near your car’s exhaust or along the “V” of the engine, you’ve got a turbocharged car. Turbo whistle?

What Was the First Production Turbocharged Car?

That honor goes to the Oldsmobile Jetfire, which started production in 1962. 

Are Turbochargers Expensive?

They can be. If you’re modifying an existing car that didn’t originally come with a turbocharger, you’ll need to do a lot of modifications to allow for the turbocharger to function. That could get expensive, with turbocharger kits costing between $1,500-$20,000 depending on the car you’re slapping those snails on. 

Likewise, replacing broken turbochargers can also be expensive, with one example being Mercedes-Benz’s AMG turbochargers, which cost more than $15,000 to replace. 

Why Do So Many Cars Have Turbochargers?

As fuel and emissions regulations become more stringent, manufacturers have had to downsize engine displacement across their lineups. In order to maintain power levels for these increasingly heavy vehicles, automakers have switched to turbocharged engines for extra oomph. 

What Is Ford’s EcoBoost?

Ford’s EcoBoost is just a name for the brand’s turbocharged products. Ford slapped the EcoBoost name on cars such as the Ford Mustang, the F-Series pickups, the new Bronco, and all the way up to Ford’s GT supercar

Get Your Own Turbocharger Kit From Vivid Racing

Does your car not have enough get-up-and-go for you? Have you almost been killed by a merging semi while your ride struggles to get to 60 mph? Do you find yourself longing for that sweet, sweet whistle of a turbocharger at peak boost? Well, then a turbocharger kit might be right for you. That’s why we’ve partnered with our friends at Vivid Racing to get you turbocharged! Click here to peruse Vivid Racing’s line of turbocharger kits. 

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Got a question? Got a pro tip? Send us a note: guidesandgear@thedrive.com