Understanding
Supercharging, Part 1

By Darren Mayer
Drawing and photos courtesy Kobelco and by Jeff Burk
3/7/03

Supercharger engineer and designer Darren Mayer plies his trade at Kobelco designing and building superchargers. Over the years, he has been involved in building winning supercharged Pro Mod and Pro Street cars. His supercharged Nova Outlaw Street car was a two-time winner of the World StreetNationals. Mitch Stott used one of his Kobleco 'chargers on the Chrysler Hemi that powered his 'Vette to the first ever five-second doorslammer pass. Mayer owns Thundercraft Engines, which built the supercharged engine shown above, and Redline Designs. In addition, he is currently the crew chief for Johnny Rocca's new "Darkhorse" '51 Merc.

This is the first of a two part series that will introduce the reader to all forms of mechanically driven compressed air devices. In the second installment Mayer will deal specifically with the advantages and disadvantages of using a supercharger by the sportsman and budget racer.

 

Supercharged! The word sends the same message to all gearheads around the globe. Doorslammers around the world rely on some form of supercharging to increase the horsepower available to propel their hot rods faster than could be expected of any naturally aspirated engine. What are the popular means of supercharging today's doorslammers? Superchargers are simply devices that force air into an engine at a greater rate than mechanically possible under normal atmospheric conditions (thus the term "blower"). If one considers supercharging as a means of increasing the amount of oxygen per intake cycle, then it is safe to say supercharging can be done via mechanical or chemical means.

CHEMICAL

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This is a way to introduce a high pressure oxygen liberating chemical into the intake stream resulting in an increased oxygen content charge that is super-cooled. Nitrous oxide is the popular door car chemical that has been making power for many years dating back to warplanes in WWII. Nitrous oxide (N2O) is an inert gas that is neither flammable nor breathable, as the oxygen atoms are attached to a nitrogen atom. Until the oxygen atoms are liberated, the gas is not useful. After the oxygen atoms are broken from the nitrogen atom (via heat) the oxygen can be used as an ingredient in the combustion process. Because of the increased oxygen, an increased fuel quantity is needed to produce the increased power and also to stop engine damage from an oxygen-rich condition called running lean.

While nitrous oxide is impressive with the amount of power it can increase to the engine's power, it is not as effective as a mechanical supercharger.

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