AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 271)

Page 271 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
Combustion
The burning of the fuel-air mixture in the cylinder.
Combustion Chamber
Space left between the cylinder head and the top of the piston at TDC; where combustion of the
air-fuel mixture takes place.
Compression Ratio
The ratio of the cylinder volume at BDC to the volume at TDC.
Options
Single value in an engine calibration. Can sometimes be referred to as an option. Options and
tables (2D and 3D) make up the tuneable portion of an engine calibration file.
Continuity
Little or no resistance in an electrical circuit to the flow of current. A solid electrical connection
between two points in a circuit. The opposite of an open circuit.
Controller
In automotive electronics, refers to a module made up of semiconductor circuits sometimes
containing imbedded software code.
Data
Information calculated or obtained directly from sensor inputs to a controller.
Data Analysis
The task of interpreting information obtained from engine sensors and controller calculations.
Density
The ratio of the mass of something to the volume it occupies. Air has less density when it is
warm and less density at higher altitudes.
Digital Circuit
Electronic circuits whose outputs can change only by specific amounts and between a limited
number of different voltages.
Stoichiometric
The air/fuel ratio for complete combustion; all the fuel is burned using exactly all the oxygen in
the air. For gasoline, this ratio is 14.7:1 or 14.7 parts of air to 1 part fuel.
Display
Device used to indicate information in a human readable form.