Turbochargers, superchargers – the two terms almost seem interchangeable; especially if your knowledge of all things engine related lies somewhere in the gray area between a some and none.
That being said, what better time is there than right now to take a crash course on the subject? Spend a couple of minutes reading over this, the second installment of the Trucks 101 series; and the next time your gearhead buddies are talking about everything under the hood, you’ll be a little bit more prepared to add to the conversation.
What makes them similar?
Both systems essentially complete the same function; they just have two different ways of going about it. Both turbochargers and superchargers use a gas compressor to, well, compress the air that is flowing into the engine; and are thus both called forced induction systems. Compressing the air allows the engine to burn fuel more efficiently; the more the air is compressed into the cylinder, the more fuel can also be added, creating a more powerful combustion.
Compression means pressure, and pressure means power. At sea level, the atmospheric pressure weighs in at around 14.7 psi, give or take a few decimals. A forced induction system is able to get approximately 50% more air into your engine’s combustion chamber, resulting in higher pressure (somewhere in the range of 20.7 to 22.7 psi), which in turn results in a bigger boom, and faster moving pistons/tires.
What makes them different?
The most important difference between a turbocharger and a supercharger lies in how the systems are powered. Each has a different way of energizing the gas compressor. A supercharger is powered mechanically using a belt that is driven by the crankshaft, while a turbocharger draws its power from the exhaust gases expelled as a result of the combustion process. Basically with a turbocharger, your vehicle’s exhaust is channeled through a turbine, which in turn powers the compressor.
The diagrams below show how each system works.
Biggest Advantage of the Turbocharger
No engine power lost in powering the turbo as the system uses otherwise “wasted” exhaust gases.
Biggest Advantage of the Supercharger
Immediate response – there is no lag time between when the gas pedal is depressed and when the engine responds. With a turbo, it takes a bit of time for the exhaust gases to get up to a high enough velocity to sufficiently drive the turbine.
Each system has their pros and cons, and a quick stroll through some online forums will likely show popular opinion is pretty well equally divided on the subject. At least now when your buddies are gathered around, you’ll be able to throw your two cents into the mix.