Whether a ride has a turbocharged or supercharged engine fitted quietly under the hood, or proudly displays the word TURBO, SUPERCHARGED, ECOBOOST, DRIVE-E or some other marketing designation in its name, the principles at work are largely the same, and largely simple.
Shoppers today are smart. They demand higher performance and reduced fuel consumption with no compromise, and to deliver on those demands, more automakers are making the shift to boosted small-displacement engines which deliver a high-performance, high-efficiency punch.
The premise is simple: Using a turbocharger or supercharger to boost an engine’s power makes a smaller engine perform like a larger one.The premise, whether on a new exotic car or a few-year-old Ford pickup, is simple. Using a turbocharger or supercharger to boost an engine’s power makes a smaller engine perform like a larger one. Used to be that this boost business was a common go-fast trick, and one of the oldest in the book. Typically, you’d take a great big honkin V8 engine, add boost, and make it perform like an even bigger and more honkin’ V8 engine.
Today, the idea is the same, but it’s often executed a little differently. Fuel savings and a reduction in emissions are realized by offsetting some of the engine’s output to a turbocharger or supercharger system, rather than simply using a bigger, thirstier engine. The performance output of a larger engine can, therefore, be generated by an engine smaller in displacement and less numerous in cylinders, creating a powerplant with equal on-demand power that burns less fuel, more of the time.
Here’s a closer look at the basics of superchargers, turbochargers, boost, and forced induction.
It’s All About Air: Gasoline can’t be burned without air. In a confined and sealed space, like an engine’s cylinders, the amount of gasoline that can be combusted is limited by the amount of air present. Gasoline combusts in the presence of air in a specific ratio dictated by the laws of science, and simply putting more gasoline into the cylinders won’t boost power, as only the gasoline molecules matched by available air molecules will combust. The rest would blow wastefully and unburned, out of the tailpipe.
The gist? Getting more air into a cylinder means more gasoline can be combusted in the same physical space, creating more power.
The most common way to get more air into a cylinder is to use a turbocharger or a supercharger. Both of these devices are simply air compressors, and both do the same thing: they pressurize the engine’s intake tract, and combustion chambers, to fill the cylinders with compressed air, allowing more gasoline to be combusted.