What Is A Supercharged Engine?

An engine needs three things to make power: fuel, air, and ignition. Spark plugs provide ignition, and your vehicle’s fuel injection system provides fuel. For an engine without a supercharger (or turbocharger, more on that later), which is also known as a naturally aspirated engine, the up and down motion of the pistons created a vacuum that draws in air. This is the method that has been used for most of the automotive engines ever produced, and it obviously works just fine, but an engine that can pull in more air can use it to produce more power. Supercharging and turbocharging, which are also known as forced induction, push air into the engine at a higher rate than the engine would be able to on its own. Think of a supercharger like a window fan, opening the window will let in fresh air, but putting a fan in the open window will greatly increase the volume of fresh air. Superchargers are sometimes colloquially referred to as “blowers” for understandable reasons.

Superchargers have actually been around for longer than internal combustion engines, with the first versions being used to help pump fresh air into coal mines. Later versions were used to provide air to blast furnaces, which is a very similar principle to automotive use, and Mercedes was the first company to make a supercharged automotive engine in 1923. There are different kinds of superchargers, but the two main ones used in motor vehicles are the Roots-type and the centrifugal. Roots-type superchargers will generally be bolted right to the intake manifold, sitting in the middle of the V for engines with a V cylinder configuration. Centrifugal superchargers are a newer type of design, and can be mounted remotely, off to the side of the engine. These usually can’t move quite as much air as a Roots-type supercharger, as they’re much smaller, but they’re perfect for smaller vehicles with smaller-displacement engines.

Both supercharging and turbocharging have their advantages. Superchargers are driven by the engine directly, so the flow of air is always an exact match to the engine speed. Turbochargers don’t put any extra strain on the engine to turn, since they’re driven off the exhaust gasses that are being expelled anyway. Most mainstream vehicles that use forced induction are doing so to give you a bit more power without hampering fuel economy, which is a perfect use for turbochargers. Supercharging tends to be used mainly in high performance applications. Because they always match engine speed, superchargers are better at low engine speeds where turbochargers struggle from the lack of exhaust pressure, so vehicles like off-road racers or drag racers that need a lot of low-end torque are popular uses for superchargers. There are performance applications for turbochargers too, but that tends to be things like road course racing, where the driver is better able to maintain higher engine speeds the whole time. Superchargers are also popular with larger-displacement engines, usually V8s, since the huge amount of air they can move is what you need for a large engine. Aftermarket supercharger kits are easy to find, but there aren’t a whole lot of factory supercharged models you can just go out and buy. Ford is unusual in that they offer two of these models, the F-150 Raptor R and the barely-street-legal Mustang GTD both come from the factory with supercharged engines.