Superchargers (also known as a blower, or a centrifugal pump) is a gas compressor used to compress air into the cylinders of an internal combustion engine. The additional mass of oxygen that is forced into the cylinders allows the engine to burn more fuel, which improves the volumetric efficiency of the engine and makes it more powerful. A supercharger is powered mechanically by belt- or chain-drive from the engine's crankshaft.
Roots Type Supercharger
The Roots type supercharger or Roots blower is a positive displacement type device that operates by pulling air through a pair of meshing lobes not dissimilar to a set of stretched gears. Air is trapped in pockets between the lobes and carried between the intake side to the exhaust. The supercharger is typically driven directly from the engine's crankshaft via a belt. In order for most typical Roots superchargers to deliver air at greater pressure than atmospheric, they should be geared so that they turn faster than the engine. It is named for the brothers Philander and Francis Roots, who first patented the basic design in 1860 as an air pump for use in blast furnaces and other industrial applications. Out of the three basic supercharger types the Roots is considered the least efficient. However, it is simple and widely used and thus is invariably the most cost efficient. It is also more effective than alternative superchargers at developing compression at low engine rpms, making it a popular choice for passenger automobile applications.
The twin-screw type supercharger is a positive displacement type device that operates by pulling air through a pair of meshing lobes not dissimilar to a set of worm gears. Air is trapped in pockets between the lobes and carried between the intake side and the exhaust. The supercharger is typically driven directly from the engine's crankshaft via a belt. Unlike the Roots type supercharger, however, the twin-screw exhibits internal compression. As the air passes through the supercharger the air pocket decreases in size towards the outlet. This increases the thermal efficiency of the supercharger beyond that of the more common Roots style supercharger.
Although the twin-screw type supercharger has more potential than the Roots type supercharger, its production costs due to close tolerances put it at a cost disadvantage. Also due to the internal compression the air exiting the supercharger exhaust "pops", this can lead to a whine noise or whistle (or scream!) that has to be tolerated or dealt with via noise suppression techniques. Although not as ultimately efficient as the centrifugal type supercharger, it does not suffer from the latter's lack of low-rpm boost.
Centrifugal Type Supercharger
The centrifugal type supercharger is practically identical in operation to a turbocharger, with the exception that instead of exhaust gases driving an impeller, there is only a compressor housing, and that is driven from the crankshaft via a drive belt. As such the centrifugal exhibits the same benefits and down-sides. Boost increases with the square of RPM (unlike the linear nature of the positive displacement devices), however low-rpm boost suffers due to the fact that air can pass back through the supercharger with little restriction until RPMs rise sufficiently to counteract the effect. Of all the belt-driven supercharger types this type exhibits the highest efficiency, and due to its design and lack of low-down boost is often employed on near standard compression engines. The Roots type supercharger and the twin-screw type supercharger, however, produce low-rpm boost and as such feel far more reactive on the road. Detractors of the centrifugal type supercharger note that it combines the worst qualities of a turbocharger and a supercharger, since it doesn't develop appreciable boost at low RPM (Boost Threshold), but still uses up prodigious amounts of engine power to operate.
HKS Supercharger Kits
HKS Rotrex Supercharger Kits are the latest in forced induction systems for the aftermarket. The centrifugal type supercharger features a unique traction drive, with a closed oil circulation system. The traction drive utilizes fixed ratio planetary rollers that are more efficient then traditional gear-wheels. Because the planetary rollers do not have teeth like traditional gear-wheels noise is decreased and reliability is increased. Click HERE for pricing.
- Edelbrock E-Force Supercharger Kits
The new E-Force Supercharger Kit uses a positive displacement supercharger that is capable of producing over 500 horsepower. This kit includes the supercharger with Eaton internals, manifold, drive pulleys, belt, and all necessary items to install on 1986 & earlier small-block Chevys with standard heads or with Edelbrock E-Tec (Vortec Style) cylinder heads. Kits are available without carburetor, or with our proven 800 cfm Thunder Series AVS carb specifically tuned to run in a supercharged application. Preliminary testing netted a peak of 507 horsepower and 487 ft/lbs of torque @ 5 psi on a 350 c.i.d. with 9.5:1 compression. Click HERE for pricing.
- Vortech Supercharger Kits
Vortech Engineering, LLC offers a variety of automotive performance products including complete supercharging systems, fuel system components and air-to-water aftercoolers for domestic and import vehicles plus marine applications. Vortech has also consistently earned praise from the automotive press for its premier centrifugal supercharging systems and performance enhancing parts and accessories. Click HERE for pricing.
- Paxton Supercharger Kits
Paxton Automotive's NOVI line is based on Paxton Automotive's race-proven gear case, which features billet steel, helical-cut gears (3.45, 3.50:1 or 3.61:1 step-up ratio), aerospace-quality high-speed bearings and direct engine oiling. Some of the fastest race cars in the world use Paxton Automotive NOVI superchargers-a testament to the NOVI's unsurpassed performance in the most demanding situations. Click HERE for pricing.
- ProCharger Supercharger Kits
Prochargers exclusive, patented, self-contained, gear-driven superchargers eliminate tapping into your oil pan, run cooler and produce more power than any of our competitor’s products. Our impellers are created with aircraft grade 7075 T-6 aluminum alloy for tremendous strength and performance. The top tier material used in the construction of every ProCharger billet impeller and compressor housing allows us to use higher step up ratios than the competition. This in turn allows increased boost levels and superior overall performance than other offerings on the market. Because of this unwavering commitment to excellence, ProCharger is the only manufacturer of self-contained superchargers offering a 3-year warranty to ensure years of trouble free performance. Click HERE for pricing.
- Whipple Supercharger Kits
Supercharger Kits Available on eBay