Superchargers and turbochargers are two frequently used terms in the automobile industry. When you hear these words, you would likely imagine cars that buzz past you with dirty fumes streaming from their tailpipes. Or cars that can zoom past you before you can finish counting 1 to 10. However, even those who are in the auto industry interchange these terms because they don’t know the differences between superchargers and turbochargers. The truth is that there are a lot of differences between the two.
To be able to further understand these two better, let’s take a look at each one first.
What are Turbochargers?
Turbocharger is a forced induction system that boosts the power output of an engine. It uses exhaust stream for energy. It is not directly connected to the engine.
It makes use of a couple of fan-like castings typically mounted on a common shaft. The first casting, called turbine, is piped to the exhaust while the other is called compressor. It is connected to the engine intake.
The exhaust runs through the turbine, which in turn spins the compressor. The turbine can spin as much as 150,000 rotations per minute. To give you a better perspective, the turbocharger can cause an RPM speed that is up to 30 times faster than that of an automobile engine.
But that kick in power won’t be experienced by the man behind the wheel right away. It would take some time for the turbine to produce the added power. There must be enough exhaust pressure to spool up the turbines, which would likely happen when the engine’s speed reaches at least 2,000 RPM.
This is referred to as the turbo lag. However, you’ll be impressed once the turbo spools up. It delivers a strong, sudden surge of power to the engine. At times, the power surge is accompanied by a distinctive hissing sound.
A car with a turbocharged engine is particularly effective at dealing with high altitudes, where cars with smaller engines will have difficulty in traversing.
Turbochargers are traditionally mated in the engines of sporty cars, giving these vehicles an extra boost in power.
Turbochargers are also mostly used in diesel engines. Turbochargers give diesel engines flat power curve, something that these engines need as they lack urge at higher RPMs.
More recently, many car makers are putting small turbocharged engines in their models instead of larger engines to comply with the high fuel economy standards set by the government.
A turbocharger enables a small engine to produce sufficient power when needed, like when the car is moving uphill. It can also use less fuel when the demand is low, such as when cruising down the highway.
What are Superchargers?
On the other hand, supercharger is a compressor that pumps fresh air into the cylinders of the engine. With more air, the engine is capable of burning more fuel and this translates to more power. This explains why supercharger is also considered a forced induction system, as it compresses air flowing into the engine and in turn providing more power to the vehicle.
Aside from being forced induction systems, both superchargers and turbochargers can provide a boost of 6-8 pounds per square inch. This means that with both superchargers and turbochargers, about 50 percent more air gets into the engine, or roughly 50 percent more power.
But those are basically the two major similarities of superchargers and turbochargers.
One of the major differences between turbochargers and superchargers is their power supply. The supercharger sources power from a belt that is connected directly to the car’s engine. It is similar to the water pump or alternator in terms of sourcing its power.
On the other hand, a turbocharger gets its power from the exhaust stream. As mentioned earlier, the exhaust runs through a turbine which in turn spins the compressor.
Also, the supercharger is directly connected to the engine through the belt. This is in contrast to the turbocharger, which isn’t directly connected to the engine.
In terms of spinning rate, a turbocharger can run up to 150,000 RPM which is a lot faster than the average speed of superchargers which is around 50,000 RPM. The reason for this is that the turbocharger is not physically connected to the engine.
Theoretically speaking, a turbocharger is considered a more efficient way of boosting an engine’s output as it uses wasted energy coming from the exhaust stream for its power source. But the downside to this is that turbocharger can cause some pressure in the exhaust system. It also doesn’t provide enough boost unless the engine runs at high RPMs.
For the budget-conscious motorist, a typical question would be which of the two is more expensive—superchargers or turbochargers? Superchargers are more expensive, albeit it is easier to install.
Which is better for you?
Now that you have an idea about the differences between these two forced induction systems, your next question may be—what’s better for my car?
In Europe, turbochargers are more commonly used because the engines of vehicles there are small, with four cylinders being the standard.
But it really depends on you as the car owner. You’ll have to weigh the pros and cons of both systems.
Superchargers can give your engines a boost at lower RPMs, while a turbocharger is more efficient at higher engine speeds. If you want power delivery to be immediate, then you should go with a supercharger because it doesn’t have the turbo lag that turbochargers are notorious for. In terms of maintenance, a supercharger is a lot easier to maintain compared to a turbocharger.
If you’re wary of fuel economy, then you should go for a turbocharged engine. Turbochargers can improve a car’s fuel economy because small engines use less fuel to ideal, aside from having less rotational and reciprocating mass that can boost fuel economy.
It’s really up to you as the consumer to decide the type of car to own or buy, taking into consideration the differences between superchargers and turbochargers.