If a BMW or Range Rover engine is built for supercharging from the start, the power increase becomes almost insane. The real job of a supercharger is to compress air and thereby move the greatest mass of air through an engine which it must then use effectively.

Supercharging an engine is the basic definition of substantially charging the cylinders with “more air” than a normally aspirated engine could ever achieve alone. The saying, “there is no replacement for displacement”, is arguable.

So why Supercharge?

In essence, any popular supercharger whether a roots, screw or centrifugal type, when compared, size for size, is a by far a more effective means of moving significantly greater quantities of air through a piston powered engine.

Compared to a naturally aspirated engine, a supercharged engine effectively forces the engine to perform as if it has far more displacement or cubic inches because the drastically increased induction process is now more determined by the engines supercharger and not just the basic displacement of the engine.

The most well known positive displacement supercharger is the Roots type which was adapted for aircraft engines towards the end of World War I. In the late 1950’s the Roots Supercharger was successfully used by Mercedes-Benz and Auto Union F1 cars and on the British F2 cars. Top Fueler drag racing legends like Don Garlits were instrumental in using Roots Superchargers.

The most commonly used Roots blowers are the big 6-71 and the 8-71 manufactured by Weiand, Edelbrock, Magnuson, I-Charger, BDS, Littlefield, and Eaton which could blow about 20-25 psi into a Hemi motor and bump the output to 2,500 horsepower with 3,200 lb-ft of torque. A typical copy in design to the Roots blower is a small block Chevy oil pump.

The Magnuson Superchargers have rotors which have a steep helix and are now classified as hybrid Roots screw type compressors. Instead of the classic top surface air entry, the air enters at the front of the unit. A vacuum referenced bypass butterfly equalizes the supercharger inlet pressure with manifold pressure. This virtually eliminates all parasitic losses other than the unit’s bearing losses. The form of the case discharge into the manifold has also been refined. Mounting a modern super-efficient unit on an intercooled base/intake manifold compliments the setup, and is the key to higher power on otherwise lower-octane fuel.

Centrifugal superchargers develop boost by imparting motion into the air. When the air meets a resistance to this motion, the slowing of the airflow turns the kinetic energy into pressure energy. For that reason, the boost and airflow throughput of a turbine supercharger are more interdependent on the characteristics of the engine it is feeding.

CLICK HERE for more information on BMW and Range Rover Roots Type or Centrifugal Supercharged engines built by 'V8 ENGINE' your Range Rover and BMW Engine Specialists.