There are some decisions we make in life that have no bad outcome. Like visiting the ice cream store, no matter what flavor you choose, you're still having ice cream. Similarly, there are choices we make when building our Mopars, but whether Hemi, big-block, or small-block, A-, B-, C-, E-, or F-body, the end result is still a Mopar so there's really no bad choice. The same goes for supercharging the engine in your Mopar. Regardless of which style you choose, Roots, Screw-Type, or Centrifugal supercharger, you'll still be force-feeding air and fuel into your engine for incredible power gains.
When it comes to power, the secret of supercharging has been out for a long time. In fact, most supercharger designs predate the invention of automobiles altogether. As an example, the Roots supercharger design can be traced to the American brothers Francis and Philander Roots, who came up with the design in 1854 as they attempted to improve the design of the waterwheel powering their textile mill. Though their bi-rotor gear pump didn't work very well at the water mill, the brothers later found it to be great at pumping large volumes of air. Before being adapted to automotive applications, Roots and other styles of superchargers were used in a variety of industrial applications, including blowing fresh air down mine shafts.
This front engine dragster...
This front engine dragster with dual blown Hemis was for sale at the Mopar Nationals last year. We're not sure if it was a replica or the real deal, but it demonstrates the common use of blowers on Hemis, in this case two of each, during the early days of drag racing.
The first application of a blower being fitted to an internal combustion engine is arguably when Sir Dugald Clerk used one on his two-stroke engine design in 1901, forcing air into the engine in an attempt to lower the inlet air temperature. While compressing air actually raises the inlet temperature, he did discover that he increased power by some six percent using forced induction. Since then, superchargers of many types have been designed and used to force air into internal combustion engines with varying levels of success, and through that process modern superchargers have evolved into one of three basic designs. Today, nearly all automotive supercharger systems are Centrifugal, Roots, or Screw-type, and fortunately there are some extremely well-engineered and reliable systems available for our Mopars new or old. With modern intercoolers to lower inlet air temperatures, there's just about no limit to the power you can make with any of these supercharger systems.
Centrifugal Superchargers...
Centrifugal Superchargers Named for their inertial compressor, Centrifugal superchargers offer manageable boost, in a small package for easy underhood mounting.
While the Centrifugal supercharger may look more like what we think of as a turbo rather than a blower, it is engine driven by pulleys or gears and thereby is considered a supercharger. Though not driven by exhaust gases like a turbocharger, the Centrifugal supercharger does share the same type of inertial compressor. This style compressor requires high rpm, sometimes 50,000, so the compressor rpm is multiplied by a precision gear-case with bearings which can be oiled either by engine oil, or by a self-contained oiling system.
Centrifugal superchargers...
Centrifugal superchargers systems are easy to install, and a reliable way to get more power from your Mopar. Most street, or even stock factory engines with cast internal parts can easily handle moderate amounts of boost without sacrificing reliability.
Unlike Roots and Screw type compressors, the centrifugal compressor, sometimes called the impeller, is not a positive displacement pump, so boost increases gradually as a function of rpm. This makes the centrifugal supercharger a great choice for street cars, especially those that are traction limited. By virtue of its design and smaller size, centrifugal superchargers can be mounted further from the intake, making them somewhat easier to intercool and keeping the compressor away from the engine, reducing air inlet temperatures.
"Big Daddy" Don Garlits had...
"Big Daddy" Don Garlits had an extremely successful career in Top Fuel, using Roots style blowers with nitro methane fuel almost exclusively. Big Daddy is still at it, making exhibition passes in one of his early "Swamp Rat" diggers as recently as the Mopar Nationals.
Most centrifugal superchargers use a belt from the crankshaft to drive the gear-case, but in extreme, high-boost applications a cogged belt or even gear-drive is sometimes necessary. Manufacturers make centrifugal superchargers in all sizes, and most come as complete kits with all the necessary components. For older muscle cars, systems are available that blow through the carburetor, and for modern Mopars the kits come with new fuel injectors and computer programmed tuning. Centrifugal supercharger systems offer great power, good reliability, and are relatively easy to install for the average mechanic.
Vortech, Paxton, and ProCharger...
Vortech, Paxton, and ProCharger all manufacture quality centrifugal supercharger systems. For the new Hemi, a centrifugal supercharger sits hidden under the hood in most cases.
This diagram shows the various...
This diagram shows the various types of superchargers, or blowers, designed over the years. Today nearly all popular automotive superchargers are Centrifugal, Roots, or Lysholm Screw designs.
For carbureted applications,...
For carbureted applications, the supercharger can be ducted into the carb, commonly called a blow-through system.