Tech Tips

In this F-Body and Third Generation World I was amazed at how much "lingo" and "shop talk" it is presumed you know. Which I didn't. Below are common abbreviations for parts, conditions, systems, and shop talk for club and member boards.

AFPR ~ Adjustable Fuel Pressure Regulator
BTDC ~ Before Top Dead Center
CFM ~ Cubic Feet Per Minute
CPU ~ Central Processing Unit
ECM ~ Electronic Control Module
EFI ~ Electronic Fuel Injection
ET ~ Elapsed Time
~ Gallons Per Hour
HP ~ Horsepower
IAC ~ Idle Air Control
MAF ~ Mass Air Flow
~ Manifold Absolute Pressure
MAT ~ Manifold Air Temperature
MPI ~ Multi Port Injection
~ EGO ~ Exhaust Gas Oxygen
PROM ~ Programmable Read Only Memory
PSI ~ Pounds Per Square Inch
RPM ~ Revolutions Per Minute
SCFM ~ Standard Cubic Feet Per Minute
SD ~ Speed Density
~ Throttle Body Injection
TPI ~ Tuned Port Injection
TSB ~ Technical Service Bulletin
WOT ~ Wide Open Throttle
VE ~ Volumetric Efficiency

Internet Chat and Board Talk

IMHO ~ In My Humble Opinion
IMO ~ In My Opinion
LOL ~ Laugh Out Loud
LMAO ~ Laughing My Ass Off
Back to Top ~ On a chat board, to send message to top of post and keep it alive.
BRB ~ Be Right Back ~ Used in live chat to take a break.
FWIW ~ For What It's Worth
BTW ~ By the Way
SOTP ~ Seat of the Pants ~ To describe the intensity of mod results.
J/K ~ Joke
AFAIK ~ As Far As I Know
OMG ~ Oh My God

Additional Definitions

Closed Loop
Open Loop
Limp Home

Open Loop Operation ~ Is the mode in which the system is being controlled by components other than the O2 Sensor, for example at engine warm up and wide open throttle.

Closed Loop Operation ~ Is the mode in which the system is being controlled by the O2 sensor, after O2 warm-up which is app. 600°F. This is effective at partial throttle and idle, and is the mode that enhances driveability and fuel economy.

Limp Home ~ In this mode the ECM declares emergency and changes timing and fuel enrichment to get you home or to a service point for repairs. Improper setup, failed sensors, and trouble codes will send the car into the limp home mode which is in actuality not a very drivable mode.

MAF ~ Mass Air Flow ~ As used by GM is a sensor used to determine the amount of incoming airflow and this calibration is used to meter fuel to provide proper air/fuel ration. This is accomplished by the use of a heated wire measuring how much air is required to cool to a certain degree. This creates a resistance that is measured and interpreted by the ECM. The MAF system is limited in the amount of CFM it can flow but is extremely tolerable to bolt on modifications.

SD ~ Speed Density ~ As a means of reducing cost GM incorporated the Speed Density system in 1990. Using the MAP (Manifold Absolute Pressure) Sensor to sense pressure changes in the intake fuel is added or subtracted accordingly. The SD system is not restricted by CFM ratios and responds to RPM variations quicker, but is more sensitive to engine modifications made. Calibrations have to be reprogrammed with each new mod.

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