A supercharger is basically a big pump that compresses and forces air into your vehicles engine to create extra horsepower. Since they can create reliable horsepower easily and inexpensively, they’re not only becoming popular selections for the aftermarket replacement crowd, but also on ORIGINAL EQUIPMENT MANUFACTURING applications. We decided to discover where Superchargers came from, how they work, what types are available, and what type is right for you.
The start of Superchargers may date back to 1860 when an Indiana man named Mr. Francis Roots created a twin-rotor commercial “air-mover”. This is where the roots style Superchargers we see today all started. Shortly after that a German engineer known as Kriggr invented twin revolving shafts that compressed and pumped air.
This is the same basic technology that can be found under the hood of many of today’s vehicles, known as the Twin-Screw Supercharger. Nonetheless it wasn’t until 1900 when Gottlieb Daimler (sound familiar? ) was issued a patent for a pump that would help move increased quantities of air and energy into a vehicles cylinders. Although it didn’t go by it’s modern name at the time, this is what many consider to be the birth of the auto Supercharger.
Soon after that, Superchargers started appearing on contest cars. Lee Chadwick was one of the first American racers to use a centrifugal Supercharger in competitive racing with successful results. World War I military aircraft then used Superchargers to overcome having less horsepower at high altitudes. By 1921 Mercedes was manufacturing Supercharged cars and the Supercharger era experienced begun Mercedes Intercooler.
At a very high level, there are three types of Supercharger: Mechanically Driven, pressure-wave, and exhaust driven. The pressure-wave Supercharger is rarely ever used in the auto world so we’re heading to leave that out of this conversation. Typically the ever popular exhaust motivated Supercharger, also known as the TurboCharger, is starting to become more commonly used in this high end market place.
Given that most people today place this type of SuperCharger in it’s own category, we are going to also going to leave that out for now and concentrate on the By mechanical means driven versions for today. These are the blowers we think of when we hear the phrase Supercharger. These people can even be separated into different categories: roots, twin-screw, and centrifugal. Each of them have their advantages and disadvantages, and hopefully after you read this article, you can decide which one works best for you.
In distinction to TurboChargers which run of exiting exhaust gasses, Superchargers are mounted to the engine and are driven by a pulley that runs from the crank. Air flow comes into the Supercharger and is then compacted before being discharged into the engine’s intake. This increases the density of the air charge before it gets into the cylinders. As the RPM’s rise and the crank starts to spin and rewrite faster, so does the Supercharger’s impellers, forcing more air to the engine and creating Boost.
Boost is created when air is being forced into the engine rather than being pulled into the absorption and is measured by PSI (pounds per rectangular inch). The more boost being created, the more dense the air demand in the engine’s burning chamber, allowing the powerplant to burn more energy, which results in more horsepower. If a car is producing 6 pounds of boost, it means it’s making 6 additional pounds of pressure over the atmospheric pressure at that elevation. Atmospheric pressure is 14. 7 psi at sea level.
As much of you are aware, cars perform their best around sea level in contrast to high elevations. This is because the air starts to thin out the higher you go and it becomes less densely packed with molecules. Superchargers provide power only under full throttle and therefor do not result the engines reliability under normal driving conditions.