# Abbreviations and Terminology ## This document contains all of the commonly used abbreviations and terminology used by rusEFI TFSI - Turbo Fuel Stratified Injection - A VW direct injection lean burn strategy GDI - Gasoline Direct Injection EGR - Exhaust gas recirculation DI - Direct injection Hall - A type of sensor that requires a power and earth wire in addition to its signal wire, the output is normally a 5v square wave. High side - A driver that is open circuit when off and powered to 5v or 12v when on. Low side - A driver that is open circuit when off and grounded to earth when switched on. High/Low driver - a pushpull or HighLow is an output that is powered "high" (12v or 5v) and switched to low (earth). SMD - Surface mount device, interchangeable with SMT SMT - Surface mount technology, interchangeable with SMD VANOS - BMW variable valve timing system Valvetronic - BMW variable valve lift system DISA - BMW variable inlet manifold resonance system VISA - BMW variable inlet manifold length system ETB - Electronic throttle body PID - A proportional–integral–derivative controller VSS - Vehicle speed sensor VCC - Common Collector Voltage; the positive supply voltage for an integrated circuit VDD - the DC Power supply connected to Drain Terminal of any FET circuit. TLE - Short for TLE8888 the Infineon chip on the MRE RE - rusEFI REO - rusEFI Online MRE - Micro rusEFI PNP - Plug and play NTC - Negative temperature coefficient, used in context of temperature sensors and refers to the resistance increasing as temperature decreases. PFI - Port fuel injection MBT - Mean best timing, used in context of spark timing, it is the spark timing that results in the best torque MFB - Mass fraction burned, often stated with a number after i.e. MFB10/MFB50/MFB90 and refers to the fraction of the fuel burned by mass. CR - compression ratio Stoichiometric - The ideal quantity of fuel to burn with a quantity of air for complete combustion. For gasoline this is 14.7:1, ethanol is 9:1 and methanol 6.47:1 TVIS - Toyota variable intake system, a variable inlet length system that switches on/off a set of longer intake manifold runners. IMEP - Indicated mean effective pressure IVC - Intake valve closing EVC - Exhaust valve closing IVO - Intake valve opening EVO - Exhaust valve opening SI - Spark injection VVT - Variable valve timing CoV - Coefficient of variability EGT - Exhaust gas temperature BMEP - Brake mean effective pressure High and low Z - High and low resistance, used in terms of fuel injectors, normally around 14 ohms for high impedance and ~4 ohms for low. Injector impedance - The resistance of the fuel injectors, see high and low Z Smart coil - A type of ignition coil that has its ignition drivers (IGBT) built into the coil, this means they only receive a 5v signal to activate. Primary coil - The primary winding of an ignition coil Secondary coil - The secondary winding of an ignition coil. LQFP - Low profile quad flat package SOIC - small outline integrated circuit TE - TE connectors, they produce the ampseal connectors on the proteus and a lot of OEM ECUs.

AAP

Absolute Atmosphere Pressure

AFR

Air Fuel Ratio - See also Lambda, Stoichiometric AFR is the ratio of air to fuel, often expressed as "14.7:1"

AIT

Air Intake Temperature

Baro

Shorthand for Barometric pressure

BTDC

Before TDC, Before Top Dead Center - See also ATDC

CAS

Crank Angle Sensor Also See [CPS](http://en.wikipedia.org/wiki/Crankshaft_position_sensor)

CLT

Coolant Temperature

CPS

Crankshaft Position Sensor

EDIS

Electronic Distributorless Ignition System - An older Ford ignition system that combined a set of ignition IGBTs and some electronics to assist the ECU. Obsolete on modern ECUs.

EGO

Exhaust Gases Oxygen - see also lambda sensor, WBO2, Often used when referring to air fuel sensors like the lambda sensor. Sometimes also used as HEGO or Heated Exhaust Gas Oxygen.

EOI

End Of Injection - See also SOI

IFR

Injector Flow Rate

IGBT

http://en.wikipedia.org/wiki/Insulated-gate_bipolar_transistor A common type of transistor used for switching high power devices like ignition coils with a low power/voltage output.

IPW

Injector Pulse Width

MAF

Mass Air Flow, often used in the context of air flow or load sensors.

MAP

Manifold Absolute Pressure or perhaps Manifold Air Pressure, often used in the context of load sensors.

NGC

Chrysler Next Generation Controller

PIP

Profile ignition pickup See http://en.wikipedia.org/wiki/Profile_ignition_pickup

RUSEFI

Really Uber Simple EFI? Robust Ultra Simple EFI? Retarded Unproven Shitty EFI?

SOI

Start Of Injection - See also EOI

Sequential

Often this refers to Sequential injection, which means the injectors fire individually for each cylinder and often at a specific crank angle. This can be handy for engines direct injection or to try to spray the injector into the cyl while the intake valve is open. If an engine can inject onto an open inlet valve it will reduce the amount of fuel wetting the port walls and help reduce low load emissions. Sequential is required for direct injection engines like common rail diesel.

Speed Density this is a method of predicting how much fuel should be delivered to an engine. This is a MAP based system which uses pressure to make a prediction of how much O2 is entering the cyl.

Staged injection

The use of 2 injectors for one cyl. This commonly means at low RPM and lower loads, one injector is turned on which allows for finer control over idle fuel delivery, while at higher RPM and higher Loads both injector inject fuel which allows for larger amounts of fuel to be delivered.

TDC

Top Dead Center

TFI

Thick Film Ignition - Ford distributor - Likely unsupported at this time.

Volumetric Efficiency, often expressed as a decimal value i.e. 0.8 (for 80%)

VOL

Short for engine volume

WOT

Wide Open Throttle