Moment you listen about blockbuster series - Fast n Furious, first thing comes to mind is power packed super cars roaring their engine. One of those cars is the Dominic Toretto (Vin Diesel) driven muscle car - 1970 Dodge charger R/T with engine's root charger out of bonnet cut section, engine itself talks about the power it packs inside and the way he does wheelie with it - Just awesome.
Apart from giving dodge a monster look with that portion of engine poping out of bonnet, it play important role in building-up a huge initial pick-up torque and that device is called as 'Supercharger'.
In general, charging an engine means forced (compressed) induction of air into the cylinder which will give boost in combustion and torque generated will be higher compared to naturally aspirated engine.
We have two widely used equipment to achieve forced induction for engine:
- Supercharger
- Turbocharger
Lets have a closer look on their working:
Supercharger
A supercharger is an air compressor that increases the pressure or density of air supplied to an internal combustion engine. This gives each intake cycle of the engine more oxygen, letting it burn more fuel and do more work, thus increasing power.
Power to run the supercharger can be provided mechanically by means of a belt, gear, shaft, or chain connected to the engine's crankshaft.
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| Centrifugal Supercharger |
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| Root Supercharger |
Turbocharger
A turbocharger is a turbine driven forced induction device that increases an internal combustion engine's efficiency and power output by forcing extra air into combustion chamber. Compared to naturally aspirated engine working at atmospheric pressure, turbocharged engine can get more air inside combustion chamber and proportionately more fuel can be burnt generating more power from each 4 stroke cycle.
Power to run the turbocharger comes from the exhaust gas of engine itself. Exhaust gas rotates the turbine of turbocharger which in turn rotate the compressor fan to pull in more air for engine.
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| Turbocharger |
Lot of commuting cars now come with turbocharged engine in order to increase the power output of the same old naturally aspirated engine. Irrespective of petrol or diesel cars, manufacturer are deploying turbo to their engine to get the best out of it.
Why turbocharger is preferred over supercharger by manufacturers:
Unlike supercharger which consume the engine power output for compressing the air, turbocharger utilize the engine waste gas to turn the turbine and generate power for air compression process. Clearly, addition of turbocharger to engine will directly multiply the power output whereas with supercharger that's not the case as it does consume back the engine power too.
Hence, turbocharging is more efficient way to increase engine power output.
Many sports car deploy Twin charger - combination of turbocharger & supercharger to increase power output and engine efficiency.