Engines with turbochargers can provide improved performance and fuel efficiency. However, what does twin-turbocharging an engine mean? It’s exactly what it sounds like. It involves using two turbochargers on one engine to provide the extra power boost and increased fuel efficiency. The idea behind twin-turbocharging an engine is that when you have two turbochargers on one engine, the charge air can more effectively be compressed into the cylinders.
What Is a Twin Turbocharger?
Turbochargers are superchargers that compress air for use in an internal combustion engine. The turbocharger uses a turbine to force air into the engine. The air is then compressed by the intake manifold, which can be used to cool exhaust gases and pistons. A twin-turbocharger is a turbocharger used in one engine to provide extra power, while another turbocharged system can be used to cool the air, which provides greater efficiency.
How Does a Twin Turbocharger Work?
A twin-turbocharger consists of two turbochargers connected to the same engine. The exhaust from the two turbochargers is routed to the same intake manifold. The exhaust from the two turbochargers gets mixed and then enters the same intake manifold, so each turbocharger is now feeding exhaust into the cylinders.
On most vehicles, two turbochargers are used. According to what you want, you can use two small turbochargers for a balance of power and fuel efficiency or two big ones for maximum power. The engine size can determine whether that engine has to have a certain amount of horsepower or torque. A beginner’s guide to twin turbos is available to learn more about twin-turbocharger systems.
Types of Twin-Turbo Layouts
There are many types of twin-turbo setups. There are mainly two designs of twin-turbo layouts on a vehicle, a sequential and an intercooler system. The sequential layout is like the two turbochargers are based on one another. The exhaust gases will go down one smaller turbo and the other big one. The smaller turbo compresses the air while the bigger one cools it, then they are sent to the same intake manifold.
On an intercooler setup, there are two individual turbines. The exhaust from the smaller one goes to the smaller turbo, while the bigger turbine compresses and cools the air. Then they are sent to the same intake manifold. The other difference between a sequential and an intercooler system is that with an intercooler system, you have to have a water-cooling source to cool the air. You can find the series twin-turbo system or the intercooler twin-turbo systems on most street-driven vehicles such as cars, trucks, and even hybrid cars.
Benefits to Twin-Turbocharging
The benefits of twin turbocharging include improved fuel efficiency and faster acceleration:
Fuel efficiency is improved because two turbochargers are used instead of one. The exhaust gases go down the smaller turbo, and then the big one compresses and cools the air to go into the cylinders. This improves fuel economy because the first turbo has to compress the air, and the second turbo has to cool it. This compresses and cools about 80% of the air with only one turbocharger before sending it into the cylinders. With dual turbos, they can compress and cool 100% of the air before sending it into the cylinders.
Faster acceleration is also an advantage of twin turbocharging. The exhaust from the small turbo is sent to the bigger turbo and then compressed into the cylinders. With only one turbo, the exhaust would take about 0.5 seconds from the turbine to the cylinders. With twin turbocharging, it takes about 0.3 seconds for the air to pass through both turbochargers and enter the cylinders. This can make a noticeable difference in acceleration, especially at lower speeds
Possible Drawbacks to Twin-Turbocharging
The drawback to twin turbocharging is that the larger turbochargers can add weight to the engine. For example, the small turbo may weigh as much as the big one because it may be necessary to use a separate shaft. The larger turbo has a housing around it bolted to the exhaust manifold.
This adds weight to the engine, resulting in a slight decrease in fuel economy. However, this is only noticeable with a larger turbocharger. Twin-turbocharging an engine can also require more space. The turbos take up more space than a single turbo, but the manufacturer usually caters to the customer and comes up with a layout.
Twin-turbocharging an engine is a great way to improve your vehicle’s fuel economy and performance. There are many pros to using twin turbochargers instead of just one large turbocharger. Most of the time, the manufacturer of a road-going vehicle will include twin-turbocharging for added performance for the customer. However, most vehicles with dual turbos get about 10% better fuel economy than a single turbo.