What is a supercharger, and what does it do? Basically, a supercharger is an air compressor. Its purpose is to increase the pressure or density of air supplied to an internal combustion engine much like a turbocharger.
With more air, the engine can also add more fuel, thus doing more work and producing more power. The supercharger itself can be powered and give power by means of either a belt, shaft, or chain connected to the crankshaft of the engine.
The downside is that superchargers sap power from the engine before they produce any themselves. Although there are various types of superchargers, the purpose of each is the same: to increase air pressure as it enters the engine. This is especially useful in aviation, where air at high altitudes is particularly thin, but any engine can unlock more performance if it gets more air pressure with more oxygen and more fuel.
Much like a turbo, increasing density is the goal. However, while turbochargers scavenge exhaust gasses that would otherwise be wasted, a supercharger tends to sap power from the engine before it produces any, as it is connected to the crankshaft and cannot be started without it.
Once the supercharger has started spinning, it pumps denser air into the engine, which starts producing more power with more air and fuel, but until then, the blower is actually drawing power.
The upside is that it takes very little time for the supercharger to speed up, so throttle response remains excellent and the power feels like it is always available.
However, superchargers can cause a spike in temperature, and if these temperatures get too high, detonation can occur. Fortunately, you can fit an intercooler as you would with a turbo, thus reducing intake temps and increasing density. Before we go into this any further, we have to stop with the generalizations and consider the different types of superchargers out there. With turbochargers, there are also various types, but they all work in relatively similar ways; you can read up on everything turbocharger-related here.
With superchargers, the different types have more diverse methods of doing their job a screw supercharger is very different from a centrifugal supercharger , but the end goal remains the increase of air pressure as it enters the intake of the engine. Two main types of superchargers will be considered although less common variants exist as well but we will list some of the subcategories too. If you're reading this, you probably have an interest in supercharged engines and already know some of the models out there, whether that's your favorite muscle car or one of the more high-end supercars.
Here we'll list some commonly known supercharged cars and sports cars , as well as some unusual cars from the past and the present that have used superchargers.
There's much to be said for superchargers and the advantages they bring to the performance of your car, although lowering fuel economy and upping the MSRP are some negatives to consider, too. Still, some of the best high-performance vehicles out there are supercharged.
We also elaborate on the differences between turbocharging and supercharging in our blog post, here. You'll often hear of superchargers being referred to by their capacity, much like an engine.
Simply put, this capacity refers to the volume of air that the supercharger can push into the engine with each rotation. Thus, supercharger capacity ratings are given in liters per revolution or cubic inches per revolution. It depends on the size, type, and application, but each of these systems has its drawbacks and advantages. That said, turbos are generally easier to package, weigh less, and are more efficient. They are also easier to tune and cost less to replace.
Yes, but they are less efficient than turbocharged diesel engines. They're uttered frequently by everyone from politicians to TV reporters to certain comedians in cars getting coffee. And while both terms are commonly understood to mean that something is given added vitality, made more powerful or highly emotional, speeded up, or boosted, most people don't understand the technologies that actually lend those words their meaning.
What are turbochargers and superchargers—and which one is better? The amount of power an internal-combustion engine can produce depends primarily on how much fuel it can burn and how quickly and efficiently it converts that heat to mechanical force. But fuel requires air the oxygen contained in air, actually to combust, so an engine's maximum output depends largely on how much air it can take in to burn that fuel.
Hence the concept of forcing-feeding an engine more air than it would normally ingest, so that it can burn more fuel and produce more power. This additional intake air can be supplied by either a turbocharger or a supercharger. Both are air compressors, but they operate and perform very differently.
A turbocharger uses the velocity and heat energy of the searingly hot and expanding exhaust gases rushing out of an engine's cylinders to spin a turbine that drives a small compressor, or impeller, that in turn stuffs more air back into the engine. A supercharger also pumps additional air into the engine, but it is instead driven mechanically by the engine via a belt that runs off the crankshaft or by an electric motor.
Each of these power-boosting technologies has advantages and disadvantages, but the most obvious difference from behind the wheel is a slight delay in response to your right foot in a turbocharged car, especially when you push deep into the throttle.
By contrast, a supercharger has no lag; because its air pump is linked directly to the engine's crankshaft, it's always spinning and instantly responsive. The power boost it provides, and therefore the engine response you feel through the seat of your pants, increases immediately in direct proportion to how far you press the accelerator.
While the turbo's primary drawback is boost lag, the supercharger's is efficiency. Because a supercharger uses the engine's own power to spin itself, it siphons power—more and more of it as engine revs climb. Supercharged engines tend to be less fuel efficient for this reason. This makes twin-screw superchargers more efficient, but they cost more because the screw-type rotors require more precision in the manufacturing process.
Some types of twin-screw superchargers sit above the engine like the Roots supercharger. They also make a lot of noise. The compressed air exiting the discharge outlet creates a whine or whistle that must be subdued with noise suppression techniques.
A centrifugal supercharger powers an impeller — a device similar to a rotor — at very high speeds to quickly draw air into a small compressor housing. Impeller speeds can reach 50, to 60, RPM. As the air is drawn in at the hub of the impeller, centrifugal force causes the air to radiate outward. That means the air leaves the impeller at high speed but low pressure.
A diffuser — a set of stationary vanes that surround the impeller — converts the high-speed, low-pressure air to low-speed, high-pressure air. Air molecules slow down when they hit the vanes, which reduces the velocity of the airflow and increases pressure. Centrifugal superchargers are the most efficient and the most common of all forced induction systems. They are small, lightweight and attach to the front of the engine instead of the top. They also make a distinctive whine as the engine revs up — a quality that may turn heads out on the street.
Any of these superchargers can be added to a vehicle as an after-market enhancement. Several companies offer kits that come with all of the parts necessary to install a supercharger as a do-it-yourself project. In the world of funny cars and fuel racers, such customization is an integral part of the sport. Several auto manufacturers also include superchargers in their production models.
The biggest advantage of having a supercharger is the increased horsepower. Attach a supercharger to an otherwise normal car or truck, and it will behave like a vehicle with a larger, more powerful engine. But what if someone is trying to decide between a supercharger and a turbocharger? This question is hotly debated by auto engineers and car enthusiasts, but in general, superchargers offer a few advantages over turbochargers. Superchargers do not suffer lag — a term used to describe how much time passes between the driver depressing the gas pedal and the engine's response.
Turbochargers suffer from lag because it takes a few moments before the exhaust gases reach a velocity sufficient to drive the turbine. Superchargers have no lag time because they are driven directly by the crankshaft. Roots and twin-screw superchargers, for example, provide more power at lower RPM. Centrifugal superchargers, which become more efficient as the impeller spins faster, provide more power at higher RPM.
Installing a turbocharger requires extensive modification of the exhaust system, but superchargers can be bolted to the top or side of the engine. That makes them cheaper to install and easier to service and maintain. For decades, turbocharged cars had to idle for about 30 seconds before being shut down so that they could cool properly.
But modern turbos have automated systems that handle that for you, so you can treat a turbocharged engine like a regular engine — or a supercharged engine. With that said, a good warmup is important for superchargers, as they work most efficiently at normal operating temperatures.
Superchargers are common additions to the internal combustion engines of airplanes. This makes sense when you consider that airplanes spend most of their time at high altitudes, where significantly less oxygen is available for combustion. With the introduction of superchargers, airplanes were able to fly higher without losing engine performance. Superchargers used with aircraft engines work just like those found in cars. They draw their power directly from the engine and use a compressor to blow pressurized air into the combustion chamber.
The illustration above shows the basic setup for a supercharged airplane. The biggest disadvantage of superchargers is also their defining characteristic: Because the crankshaft drives them, they must steal some of the engine's horsepower. A supercharger can consume as much as 20 percent of an engine's total power output.
But because a supercharger can generate as much as 46 percent additional horsepower, most think the trade-off is worth it. Supercharging puts an added strain on the engine, which needs to be strong to handle the extra boost and bigger explosions. Most manufacturers account for this by specifying heavy-duty components when they design an engine intended for supercharged use. This makes the vehicle more expensive.
Superchargers also cost more to maintain, and most manufacturers suggest high-octane premium-grade gas. Despite their disadvantages, superchargers are still the most cost-effective way to increase horsepower.
Superchargers can result in power increases of 50 to percent, making them great for racing, towing heavy loads or just adding excitement to the typical driving experience. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Under the Hood. Engine Performance. How Superchargers Work. Troy Coughlin, Jr. Many race cars have supercharged engines.
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