Types of Turbochargers in Cars - Features, Benefits & More

Technological development of automobiles has always continued to reach new heights. Turbochargers in cars are a result of continuous developments in the automobile industry. 

A turbocharger is a device that improves a vehicle’s overall performance and efficiency. Here, we will explore all the different turbochargers you can fit into your vehicle.

First, let us look at the six different types of turbochargers in automobiles:

1. Single-Turbo

The underlying concept of a single turbocharger is that you can achieve different torque characteristics by differing the size of each element within a turbo. Larger turbos have the capacity to provide a high level of top-end power. On the other hand, smaller turbos can generate better low-end power with the ability to spool faster.

Features and Benefits:

Listed below are essential features and benefits of single turbochargers-

• It is the easiest to install.
• It allows smaller engines to generate the same power as larger NA (naturally aspirated) engines. 
• Single turbochargers are a cost-effective way to increase the power and efficiency of a vehicle's engine.

Limitations:

Given below are the limitations-

• Turbo response is slow, unlike alternative turbo setups.
• The narrow range of RPM or Revolutions per minute creates sizing issues, more because drivers have to choose between better high-end power and good low-end torque.

2. Twin-Turbo

When an additional turbocharger is added to a car's engine, it is known as a twin turbocharger. You can use a single turbocharger for each cylinder bank. However, as an alternative option, you can use a smaller turbocharger for low RPM (revolutions per minute) and a larger turbocharger for high RPM.

Features and Benefits: 

Listed below are the characteristics and benefits of this type of turbocharger in cars- 

• Twin sequential turbocharging facilitates a wide operating RPM range and ensures better torque at low revs.
• It reduces turbo lags and also generates power at high RPMs.

Limitations: 

• Twin turbochargers are associated with increased costs and high complexity. 

3. Twin-Scroll Turbo

This turbocharger type needs a divided inlet turbine housing and exhaust that facilitates the pairing of the correct engine cylinder with each scroll separately. Let us use an example for better understanding. Suppose there is a four-cylinder engine with firing order 1-3-4-2. Here, cylinders 1 and 4 will feed to one turbo scroll, while cylinders 3 and 2 will feed to a different scroll.

Features and Benefits:

The following are its features and resulting benefits-

• It efficiently delivers exhaust gas energy to the turbo. As a result, each cylinder receives denser and purer air. 
• Considering that the exhaust turbine receives more energy, it produces more power. 
• This turbocharger ensures tuning flexibility because of the possibility of more valve overlaps which do not hamper exhaust scavenging. 
• There is the possibility of a wider RPM range depending on different scroll designs. 

Limitations:

However, these turbos also carry the following limitations:

• It is associated with high expense as the system is complex and requires exhaust manifolds, turbos and complicated turbine housings. 
• Moreover, this turbocharger type demands a particular engine layout and exhaust design.

4. Variable Geometry Turbo (VGT)

These make exceptional turbochargers with aerodynamically shaped vanes in turbine housing at the turbine inlet. In light commercial vehicles and passenger cars, rotation of the vanes ensures variation of gas-swirl angle and cross-sectional area. The internal vanes change the turbo A/R (area-to-radius) ratio to align itself with the engine RPM, which results in an excellent performance. 

When the RPM is low, a low A/R ratio enables the turbo to increase exhaust gas velocity and spool up quickly. When the A/R ratio increases at higher revs, it increases airflow. The result is a wide and smooth torque band, low boost threshold and low turbo lag. 

Features and Benefits: 

Listed below are its characteristics and benefits-

• Only a single turbo is required to simplify and make the sequential turbo setup more compact. 
• The turbocharging takes place effectively at a wide RPM range. 

Limitations: 

Its limitations are as follows-

• Exotic heat-resistant materials have to be used to make the vanes because of the high temperature of the exhaust gases. It automatically increases cost. 
• Only luxury and high-performance cars use this turbocharger.

5. Variable Twin Scroll Turbo (VTS)

This type of turbocharger is made of a combination of twin-scroll turbo and variable geometry turbo. It uses a valve that directs the exhaust airflow to a single scroll. In addition, it can also change the opening of the valve to distribute the exhaust gases to both scrolls. The design of a VTS turbocharger makes it a cost-efficient and stronger alternative option VGT turbocharger.

Features and Benefits:

Given below are its benefits-

• As it is less expensive than VGTs, many people prefer this turbocharger type for gasoline turbocharging. 
• It facilitates a wide and flat torque curve. 

Limitations: 

Provided below are its limitations-

• VTS is associated with increased expenses and mechanical complexities when compared with a single or twin-scroll turbocharger.
• Its technology is nothing new, and production is challenging.

6. Electric Turbochargers

An electrical motor is used with these turbos to spin the compressor from the start and through lower revs. It continues until the exhaust volume power increases enough to make the turbocharger work. It removes turbo lag and helps to produce sufficient gas for turbocharging.

Features and Benefits: 

Given below are its characteristics and resulting benefits- 

• This type of turbocharger can eliminate most of the problems involved with turbocharging.
• An important feature of this turbocharger type is that it ensures a wide and effective RPM range with an even torque distribution throughout. 
• It facilitates the recovery of wasted energy by connecting the electric motor to the exhaust turbine. 

Limitations: 

Listed below are factors you need to keep in mind- 

• Weight and packaging are crucial issues, more so because of the battery on board which is essential for power supply to the turbo when required. 
• You must ensure that the electric motor remains cool to prevent damage and other reliability issues. This applies to controllers as well. So, an electric turbocharger is associated with increased expenses and complexities.

People fit a turbocharger into their vehicle's engine to improve its performance and efficiency. It is a device that uses forced induction to force more air into the engine than its standard intake. As a result, more fuel is burned during internal combustion, resulting in more power and torque.

Now, let us take a look at how this works: 

• There are two major components in a turbocharger—a turbine wheel and a compressor. They are held together by a shaft and remain enclosed within a snail-shaped housing with an inlet and exhaust port. 
• When the engine produces exhaust gases, it enters at very high pressure through the inlet port of a turbocharger.
• This high pressure of air facilitates the turbine's spinning, which, in turn, spins the compressor wheel. 
• This spinning of the compressor wheel draws out a lot of air that remains compressed, and the exhaust port releases the air. The compressed air flows to the cylinders through pipes and an intercooler. 
• As the exhaust gases are hot, the air will be very hot. So, an intercooler is necessary for cooling the air before it passes to the cylinders.
• Considering that a turbocharger runs at a very high speed, it has an oil cooling system. In addition, some turbo systems have waste gate valves, which are responsible for diverting excessive gases from the turbocharger when a lot of exhaust gases come out from the engine. The waste gate valve is responsible for controlling the turbine's rotational speed and preventing damage to it.

Listed below are the advantages of a turbocharger:

• You can use turbochargers for cars that run on both petrol and diesel. 
• A major benefit of turbochargers is that you can use them on any vehicle, for example, cars, buses, trucks and ships. 
• Another advantage is that your car’s engine will receive more power output even if its size remains the same. In simpler words, every stroke of the piston on the cylinders will generate more power than the usual amount. 
  
• A turbocharger often ensures better fuel efficiency. This is because when you fit an engine with a turbocharger, it becomes much smaller and lighter than the engine that is not fitted with one. 
• Turbo engines can result in more torque in the lower rev range, which, in turn, results in good acceleration at the initial level. 
• Turbochargers are eco-friendly because they burn fuel with oxygen. So, it results in less air pollution. 
• As cleaner air enters the cylinder, a turbo engine generates less noise than a naturally aspirated engine. So, turbo engines are more refined.

Listed below are the disadvantages of a turbocharger in your car:

• More power means more energy output in a second. If your car uses a turbocharger, it has to put in extra energy during usage. So, it needs to burn more fuel than usual. 
• Turbo lag is a common problem in a turbo engine. Automobile experts define it as a slight delay in power delivery after the driver presses the accelerator pedal.
• Adding a turbocharger to your vehicle's engine will increase its mechanical complexity. In addition, if its parts fail, it will have a negative impact on other engine components.
• Turbo engines can be less reliable than NA (naturally aspirated) engines. This is because a turbocharger works under high pressure and temperature. So the crucial parts might get damaged more quickly, leading to breakdowns.
• Turbochargers are expensive. Moreover, it must be well-maintained. Regular maintenance charges further increase the overall expenses of a turbocharger. 
• Considering that the engine capacity is small, turbo engines cannot generate a throaty exhaust note. 

In the times that we live in, people focus on meaningful experiences and travelling by car is a special and enjoyable experience. Powerful engines are a characteristic of modern cars, and a turbocharger has contributed to the overall improvement of car engines. This blog has provided essential details of turbochargers in cars and their different types for your benefit.