[Company Logo Image]     Performance Trends Inc

    Producing Quality Computer Tools for Racers and Engine Builders since 1986







What is Supercharging?


Typical Supercharger - Image courtesy of Magnuson Products Inc
A supercharger forces air into the combustion chamber to provide more oxygen to provide better combustion. They are like air compressors and come in many different configurations.

How they work

Supercharges usually run off of a pulley that is connected to the engine like the alternator or power steering pump. They force the air into the combustion chamber by compressing the air via a turbine or screws.


Types of Superchargers

There are 2 main types of Superchargers, Positive Displacement and Dynamic Compressors.

Positive Displacement

Positive Displacement superchargers produce a fixed amount of pressure that doesn't increase much as the engine increases RPM's. That means the added benefit decreases at higher RPM's.



Roots Type Supercharger
Cross Sectional View of a Roots Type Supercharger - Image courtesy of Mustang Revolution
The Roots Supercharger (or Blower) uses a pair of meshing lobes. They trap air in pockets surrounding the lobes and then the air is forced from the intake side of the supercharger to the exhaust side.

The Roots Supercharger was patented in the 1860's by the brothers Francis Marion and Philander Roots of India.

Lysholm Screw


Lysholm Screw Supercharger
Cross Sectional View of a Lysholm Screw Supercharger - Image courtesy of Sprintex
The Lysholm Screw aka Twin Screw Supercharger works by pulling air through a set of counter rotating screws that resemble worm gears. These screws are high tolerance and have low leak levels compared to the Roots-Type superchargers.

Lysholm Supercharges are named after Alf Lyshom whom invented them.

Scroll-Type or G-Lader


Scroll Type Supercharger
Scroll Type Supercharger taken apart. Notice the broken vaine. Supercharger - Image courtesy of Blog Auto Parts
The Scroll Type Supercharger works by spinning orbitally and has a very unique spiral shaped rotating lobe. This type of supercharger has higher efficiency, is lower in noise and has less pressure fluctuation.

This superchargers basic concept what was invented in France by Leon Creux in 1905.

Dynamic Compressors

Unlike the Positive Displacement superchargers that produce an almost fixed pressure output at any RPM, the Dynamic Compressors produce more pressure as the RPM's increase.



Scroll Type Supercharger
Cross Sectional view of a Centrifugal Supercharger - Image courtesy of A & A Corvette Performance
The Centrifugal Supercharger is basically half of a Turbo charger. The exhaust turbine is replaced with a belt, gear system or chain to drive the compressor. These superchargers are considered to be the most efficient but doesn't' produce boost a low RPM's.

Axial Flow


Scroll Type Supercharger
Axial Flow Supercharger - Image courtesy of crxsi.com
Axial Flow Compressors work much like Jet Engines. They have several fan blades that compress the air in stages inside the housing. These compressors have a much lower outlet air temperature than other compressor types.

Pressure Wave

The Pressure Wave Supercharger is very complex, rarely used in any vehicles and is not simulated in our Engine Analyzer programs. But if you would like more information on them you can check out this page: Pressure Wave Supercharger.


Programs that take Supercharging into account

We have 3 programs that work with Supercharging when conducting Engine Simulation: Engine Analyzer v3.4, Engine Analyzer Plus v3.4 and Engine Analyzer Pro v3.9.

And we have 3 other programs that take Supercharging into account when making calculations. Compression Ratio Calculator Plus v2.3 calculates Effective Compression Ratio that is used by Supercharger companies to show requirements for boosted engines. And Fuel Economy Calculator v1.1 that takes the extra drag of a supercharger into account for calculating your Miles Per Gallon. And Fuel Injector Calculator v1.1 also takes Supercharging into account.

And if you have a Drag Racing car or a Road Racing car with a Supercharger and want capture your vehicles runs with a data logger we have our Drag Racing Datamite and Road Race Circle Track Datamite v3.7 software that can capture up to 3 different RPM's including the supercharger RPM with our Datamite III USB data aquisition hardware.

Scroll Type Supercharger
An example of how a Scroll Type Supercharger works - Image courtesy of absoluteastronomy.com