Glossary

AC (Alternating Current)

an electrical current whose magnitude and direction vary cyclically, as opposed to direct current, whose direction remains constant. The usual waveform of an AC power circuit is a sine wave.

AFR (Air Fuel Ratio)

The ratio between the mass of air and the mass of fuel in the air:fuel mixture. For gasoline the stochiometric mixture is 14.7:1 at sea level. In naturally aspirated engines, maximum power is commonly reached at ratios between 12.5 and 13.3:1

Alpha-N

Fuel calculation method based on angle of the throttle and engine speed.

Batch Injection

All injectors discharging fuel at the same time, usually once per engine revolution.

Boost Control

Electronically controlled valve that controls the amount of pressure the turbo is allowed to build.

CAN bus (Controller Area Network)

A multicast shared serial bus standard, originally developed in the 1980s by Robert Bosch GmbH, for connecting electronic control units (ECUs).

CAS (Crank Angle Sensor)

CLT (CooLant Temperature sensor)

Temperature sensor in the coolant system. Helps to determine warmup fuel enrichments on a cold engine.

Closed Loop

In a closed loop system the ECU is using feedback from a EGO sensor in order to adjust the air/fuel mixture.

DC (Direct Current)

The constant flow of electrons from low to high potential. In direct current, the electric charges flow in the same direction, distinguishing it from alternating current (AC).

DVM (Digital Volt Meter)

Small measuring device that typically can measure voltage, amperage, and resistance.

DPAK (Discrete Packaged IC)

DSP (Digital Signal Processor)

ECM (Electronic Control Module)

See ECU.

ECU (Electronic Control Unit)

Also known as an Engine Control Unit or EMS (Engine Management System). An electronic system, fundamentally a computer, that controls an internal combustion engine by reading several sensors in the engine and using the information to control its fuel and/or ignition systems. Genboard is a programmable ECU.

EDIS (Electronic Distributorless Ignition System)

Ford ignition system found on almost any fuel injected 4 cylinder vehicle between 1990 and 1995. This module controls the spark timing based on signals from the crank position sensor and the main ECU. Since Genboard can directly control ignition functions, compatability is mainly for users who already have their ignition controlled by an EDIS module.

EFI (Electronic Fuel Injection)

A means of metering fuel into an internal combustion engine. In modern automotive applications, the fuel metering task is only one of several functions performed by an engine management system.

EGO (Exhaust Gas Oxygen)

Sensor located in the exhaust system that measures the Air/Fuel ratio.

EGT (Exhaust Gas Temperature)

Sensor located in the exhaust system that measures the temperature of the exhausted engine gasses. Can be used as an indicator of how well the air/fuel ratio in the combustion chamber is being burnt. Also used to avoid destructively hot exhaust gas temperatures.

FET (Field Effect Transistor)

An electronic component that can be used for amplification, switching, voltage stabilization, and many other functions. User configurable FETs are used in a switching capacity in the Genboard application.

Firmware

Software that is embedded in a hardware device. It is often provided on flash ROMs or as a binary image file that can be uploaded onto existing hardware by a user.

Hardware

The physical part of a computer, including the digital circuitry, as distinguished from the computer software that executes within the hardware.

Software

A list of instructions that enables a computer to perform a specific task, as opposed to the physical components of the system (hardware).

Econoseal III

Type of wiring connector which provides an interface between Genboard and engine components. There are two Econoseal III connectors on a standard Genboard; one with 36 pins and one with 18 pins. The abbreviated notation referring to these connectors is EC-36 (36 pin) and EC-18 (18 pin). If another number follows either of these abbreviations, it is a reference to a pin number in that connector. For example, EC-36/1 refers to pin number one on the 36 pin connector.

Alubus

The extruded aluminum case which houses the Genboard circuit board and associated components. This is the standard and recommended case for Genboard, but a case from a different source may be used.

Thermocouple

Temperature sensor.

K-type Thermocouple

(Also known as "type-k") General purpose thermocouple capable of measuring temperatures between -200 and 1200 degrees Celcius. Made from Chromel (Ni-Cr alloy) and Alumel (Ni-Al alloy). K-type thermocouples are used for measuring exhaust gas temperatures in the Genboard application.

Flyback

A method of absorbing high voltage spikes in electronics created by inductive loads (injectors, ignition coils, and any other device actuated by a coil of wire) when they are switched off.

Genboard

Genboard is one of the most advanced EFI systems ever developed.

Hall effect

Method of sensing engine speed and position based on a slotted metal ring passing through a magnetic field.

HighZ

High Impedance Injector designed for 12V. Typically HighZ injectors have an internal resistance of more than 10 ohms.

Impedence

Electrical resistance of a coiled wire, measured in Ohms

TDC (Top Dead Center)

Refers to the position of the crankshaft when the number one cylinder and piston are fully extended in the direction of the cylinder head.

BTDC (Before Top Dead Center)

Refers to the position of the crankshaft, usually in degrees, relative to TDC, after the number one cylinder and piston have passed top dead center while rotating.

PWM (Pulse-width Modulation

Rapidly switching a device on and off to emulate a tightly controlled voltage regulated system. Pulsewidth modulation costs less to implement than an analog system which gives the same result and reduces power consumption of the device being powered.

COP (Coil Over Plug)

An ignition system in which each spark plug is fitted with its own coil, and the spark plug connector and ignition coil are integrated into one unit. In a dual overhead camshaft engine, this system is know as "coil over plug". In an overhead valvetrain engine, this system is known as "coil near plug" since the ignition coils are not integrated with the spark plug connector and are not located over top of the plug.

IAC (Idle Air Control)

An electronically controlled valve that directs air around the throttle baffle, thus controlling the engine idle speed.

IAT (Intake Air Temperature)

Temperature sensor located somewhere in the inlet. Air mass varies based on temperature, so we use this sensor to correct the VE.

IGBT (Insulated Gate Bipolar Transistor)

Transistors capable of very rapidly switching high power circuits. Used to control ignition coils in the Genboard application.

Knock Sensor

A small piezoelectric microphone, on the engine block, connected to the engine's ECU. Spectral analysis is used to detect the trademark frequency produced by detonation at various RPM. When detonation is detected the ignition timing is retarded, reducing the knocking and protecting the engine.

Lambda

Ratio between the air:fuel ratio and the ratio which represents a stoichiometric mixture for the given fuel. Any fuel at stoichiometric mixture gives a Lambda of 1. Lambda values greater than 1.0 indicate excess air and are called lean mixtures. Lambda values less than 1.0 indicate excess fuel for complete combustion, and are called rich mixtures.

LCD (Liquid Crystal Display)

Small display usually used for displaying menus, values etc. while Genboard is active.

LED (Light Emitting Diode)

Small, low powered light, usually used for indicating status and/or activity.

Loadsite

Single coordinate in either the VE table or the spark table.

LowZ

Low Impedance Injector that has a very low resistance, typically less than 5 ohms.

MAP (Manifold Absolute Pressure)

Measures pressure in the engine's intake manifold. Pressure is measured relative to a perfect vacuum, not to atmospheric pressure. Very important part in a Speed Density based injection system; engine load is based around pressure in the intake manifold.

MCU (Micro Controller Unit)

NBO2 (Narrow Band Oxygene)

Oxygen sensor located in the exhaust. The narrowband version is used in many (espcially older) OEM applications.

NTC (Negative Temperature Coefficient)

OEM (Original Equipment Manufacturer)

PDA (Personal Digital Assistant)

Small handheld device sometimes used for logging data from the ECU.

PID (Proportional Integral Derivative)

RPM (Revolutions Per Minute)

A measure of engine speed based on the crankshaft rotation.

RPM Trigger

Usually either a Hall or VR sensor located near a tooth wheel on the crankshaft.

Sequential Injection

SMD (Surface Mount Device)

Electrical components designed for mounting on the surface of a PC board.

Stepper

See IAC.

Stoichiometry

The optimal mixture of air and gasoline. Different types of fuel have different stoichimetric values.

TPS (Throttle Position Sensor)

Sensor indicating the angle of the throttle.

VE (Volumetric Efficiency)

The engines ability to fill the avalible volume in the cylinders.

VE Table

The ratio (or percentage) of what volume of fuel and air actually enters the cylinder during induction to the actual capacity of the cylinder under static conditions. Engines that can create manifold pressures above atmospheric will have efficiencies greater than 100%.

VEMS (Versatile Engine Management System)

VR (Variable Reluctance)

A magnetic sensor paired with a toothed wheel to measure crankshaft position and rotational speed (RPM). The position of the crankshaft triggers events such as ignition coil discharge or injector opening.

Wasted Spark

An ignition system in which both ends of the secondary windings of the ignition coil are connected to spark plugs. The spark plugs which are fired from that coil are paired so that when they are fired, one cylinder is on the power stroke and the other is on the exhaust stroke. The plug on the exhaust stroke resists firing because of the conditions in the combustion chamber, and most of the power is directed to the plug in the freshly charged cylinder. Since the small arc created in the cylinder on the exhaust stroke does nothing useful in this system, it is called "wasted" spark.

WBO2 (Wide Band Oxygene)

A sensor inserted into the exhaust system of a gasoline engine to measure the concentration of oxygen remaining in the exhaust gas. a wideband sensor is accurate through a much wider range of air:fuel ratios than older narrow band sensors, which are only accurate when air:fuel ratios are very close to stoichiometric (14.7:1 air:fuel ratio).

WOT (Wide Open Throttle)