A supercharger is another invention in the piston type of internal combustion engine to increase its working efficiency. It is an air compressor that increases the pressure or density of air that enters an engine’s combustion chamber due to excessive working.
The combustion of a fuel-air mixture in the combustion chamber of an automobile engine produces mechanical movement. The engine performs better when a supercharger is added because it increases the air pressure entering the chamber, allowing more fuel to mix and burn.
In this reading, we’ll explore what a supercharger is, its diagram, types, and how it works. We’ll also learn its difference from a turbocharger, plus its advantages and disadvantages.
Let’s begin!
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What Is A Supercharger?
A supercharger is a mechanically driven component that is used in piston engines to pump pressurized air into the intake manifold using an air compressor or blower. The high pressure increases the level of air entering the cylinder during the intake stroke.
Superchargers let the engine burn more fuel and do more work as each intake circle of the engine gets more oxygen. A gear, belt, shaft, or chain connected to the engine’s crankshaft is what mechanically drives these power components.
This scenario is where another component has more advantages than a supercharger; it is called a turbocharger. Although the part is known as a supercharger, it is named a turbosupercharger or turbo. It produces power by using a turbine that runs on exhaust gas from the combustion process.
Diagram Of a Supercharger
Types of Supercharger
Superchargers can be categorized based on their design and operating principles. Here are the main types:
Centrifugal Superchargers
These superchargers are fairly easy to package in aftermarket retrofit installations. It uses a variable-ratio centrifugal supercharger that contains a continuously variable pulley drive mounted to a conventional compressor.
Vee-type engines typically pack their factory superchargers in the valley of the vee, favoring longer, lower, narrower packaging.
Roots Superchargers
The roots superchargers are the most popular type. In their setup, two counterrotating shafts are equipped with lobes that force air down across them. Generally, air enters the top of the unit and escapes through the bottom portion.
Twin-Screw Superchargers
The working principle of a twin-screw supercharger involves forcing air through two meshing rotors that spin next to one another. The rotor lobes of a twin-screw supercharger create pockets that trap air, just like in a Roots supercharger. A twin-screw supercharger compresses the air within the rotor housing.
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How A Supercharger Works
A supercharger is a device that boosts the power and torque of an engine. It is also known as forced induction since it compresses the air that the engine takes in. An internal combustion engine draws air into a cylinder, compresses it, and ignites a mixture of fuel and air.
Once ignited, it generates a power stroke in the piston, which then transfers energy to the wheels. The performance of a vehicle is directly proportional to the displacement of its engine. A larger engine can provide the necessary power when needed, but so can a forced induction system like a supercharger.
The crankshaft of an engine is typically what drives superchargers, which run on belts. A turbocharger uses waste heat from the exhaust, but this type of forced induction doesn’t. The engine of a supercharged car draws air through the intake, hood scoops, and any other openings while it is operating.
The supercharger then compresses the air, increasing its pressure and density. In this manner, the engine gets more air through the same intake, increasing its ability to burn fuel and improving performance.
Nevertheless, the added benefit is not without a price. The most notable being a 20% reduction in horsepower. Conversely, the belt drive extracts significantly less horsepower from the engine than a supercharger, resulting in a net increase in horsepower of approximately 30% to 50%.
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Superchargers Vs. Turbochargers
The similarities between turbochargers and superchargers are that they both increase the working power of the engine. They both have a compressor that forces air into the engine intake manifold. Therefore, both components serve the same function in automobile engines.
The difference between the two components is that superchargers use mechanical power to spin their compressor.
A gear, belt, or chain extracts this power from the crankshaft. In the case of turbochargers, the combustion cycle’s exhaust gas generates the power. The component is also a supercharger, but the power source makes it different.
Now the question is, which of them is better, the turbo or the supercharger?
You can use both of these pieces of equipment to increase power and save fuel. And they both have their benefits and limitations. Turbochargers use free energy that will completely evaporate into the atmosphere, but instead, the gas is used to power the part.
The driving turbine increases exhaust backpressure, which exerts some load on the engine. The load applied is less when compared with the supercharger. The mechanical load superchargers exert on the vehicle is way higher due to the big and heavy blower they contain.
These blowers consume 900 crankshaft horsepower in an engine rated at 7,500 total horsepower. However, a supercharger boosts the engine almost instantly, in contrast to turbochargers that experience some response lag.
The engine waits for enough exhaust gas to be built up for the turbocharger to pick up. This is why the supercharger is still used. Most manufacturing companies prefer not to waste precious horsepower on superchargers, which is why they mostly use turbochargers.
Twin Charging
Twincharging is a term given to the vehicle that incorporates both a belt-driven supercharger and an exhaust-driven turbocharger. In its design, there is a complex series of bypass valves in the induction and exhaust systems and also an electromagnetic clutch. The supercharger will provide a boost at low engine speeds.
Both systems generate boost at the midpoint of the rev range. The system disconnects from the supercharger and isolates the associated ducting at the highest revs. The addition of both systems eliminates their disadvantages. Finally, let’s quickly look at the advantages and disadvantages of superchargers.
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Advantages
Below are the benefits of a supercharger in a piston engine:
- Great atomization of fuel
- Better air/fuel mixture
- Higher power output
- Better scavenging products
- Good torque characteristics over the whole range
- Smooth and complete combustion
- Fuel with poor ignition quality can be used
- Less exhaust smoke
- Mechanical efficiency is improved
- Improved cold starting
- Fast acceleration of the vehicle
- A quick reflection of a power boost was observed.
Disadvantages
Despite the advantages of a supercharging device, some limitations still occur. Below are the disadvantages of a supercharger:
- Gas loading is increased
- Increased heat loss due to increased turbulence
- The cooling requirement of the engine is high
- Increased thermal stress
- There is a high detonation tendency in SI engines.
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Conclusion
Superchargers are powerful devices that boost an engine’s performance by forcing more air into the combustion chamber, allowing for a higher amount of fuel to burn and resulting in significantly increased power output.
Unlike turbochargers, superchargers are driven directly by the engine’s crankshaft, providing instant power without lag.
Superchargers are especially popular in muscle cars, drag racing, and high-performance vehicles where immediate throttle response is critical. Understanding how superchargers work and maintaining them properly can lead to impressive performance gains and long engine life.
FAQs on Superchargers
What does a supercharger do?
A supercharger compresses and forces more air into the engine, increasing the amount of oxygen available for combustion, which leads to more power.
How is a supercharger different from a turbocharger?
The engine mechanically drives a supercharger (usually via a belt), while exhaust gases power a turbocharger. Superchargers deliver instant power without turbo lag.
Does a supercharger improve fuel efficiency?
Generally, no. Superchargers tend to reduce fuel efficiency because they draw power directly from the engine to operate.
What are the main types of superchargers?
The three main types are Roots-type, Twin-screw, and Centrifugal superchargers, each with different characteristics in terms of boost delivery and efficiency.
Can I add a supercharger to any engine?
Not always. Adding a supercharger often requires engine modifications and tuning to handle the increased air pressure and stress.
What are common signs of a failing supercharger?
Symptoms include reduced engine power, whining noises, oil leaks, and engine misfires.