If you have any to add, please post them in a reply and I'll add it to the list and delete your reply.
However, DO NOT post asking about general internet terms/slang/acronyms. You simply need to google those to find your answers.
NOTE: This thread is subject to regular pruning.
Acronyms & Basic Terminology
- 4EAT – Four Speed Electronic Automatic Transmission
- 5MT – Five Speed Manual Transmission
- 5EAT – Five Speed Electronic Automatic Transmission (includes Sportshift)
- 6MT – Six Speed Manual Transmission
- ABS – Anti-lock Braking System
- AFR (or A/F) - Air to Fuel Ratio
- ALK - Anti Lift Kit
- ALS: Anti Lag System (EM trick to keep the turbo spooled when off the throttle)
- AT – Automatic Transmission
- ATDC = After Top Dead Center (relative to piston location)
- ATF – Automatic Transmission Fluid
- AutoX – Autocross
- AVCS – Active Valve Control Sysem
- AVLS – Active Valve Lift System
- AWD – All Wheel Drive
- AWHP - All Wheel Horse Power
- BBK - Big Brake Kit
- BHP – Brake HorsePower (measured BEFORE transmission)
- BOV – Blow Off Valve
- BPV - By-Pass Valve
- BTDC - Before Top Dead Center (relative to piston location)
- CAI – Cold Air Intake
- Cat – Catalytic Convertor
- Catback -- Catback (after the Catalytic Converter) exhaust section
- CBE = Cat Back Exhaust
- CEL – Check Engine Light
- CF – Carbon Fiber
- Cf -- drag coefficient or coefficient of drag (airflow resistance)
- CO2 – Carbon Dioxide
- Diff – Differential
- DP -- Down Pipe
- DC -- Double Clutch
- DCCD -- Driver Controlled Center Differential
- DOHC – Dual Overhead Camshaft
- DRL = Daytime Running Lights
- EBC – Electonic Boost Controller
- ECT - Electronically Controlled Transmission
- ECU – Electronic Control Unit (engine control unit)
- EDM - European Domestic Market
- EFI – Electronic Fuel Injection
- EG – Subaru 6-cylinder engines (up through mid to late 90’s)
- EG33 – Subaru 3.3 litre 6-cylinder engine code (SVX)
- EGT - Exhaust Gas Temperature
- EJ – Subaru 4-cylinder engines (early 90’s and newer)
- EJ20 – Subaru 2.0 litre 4-cylinder engine code
- EJ205 – Subaru 2.0 litre turbo engine (US WRX)
- EJ22 – Subaru 2.2 litre 4-cylinder engine code
- EJ25 – Subaru 2.5 litre 4-cylinder engine code
- EJ255 – Subaru 2.5 litre turbo engine (US Forester XT, Baja Turbo)
- EJ257 – Subaru 2.5 litre turbo engine (US WRX STi)
- EM - Engine Management
- EMS = Engine Management System
- EWG - external wastegate
- EZ – Subaru 6-cylinder engines (post EG series H6 engines)
- EZ30R – Subaru 3.0 litre 6-cylinder engine code (BL/BP Legacy and new Outback)
- FDR - Final Drive Ratio
- FHI - Fuji Heavy Industries
- FMIC – Front Mount Intercooler
- FWD – Front Wheel Drive
- FSB -- Front Sway Bar
- H4 – Horizontally Opposed 4 cylinder (boxer)
- H6 – Horizontally Opposed 6 cylinder
- HF - High Flow (usually used in conjunction with a catalytic converter)
- HID – High Intensity Discharge (headlights)
- HT-- Heal and Toe
- IC -- Intercooler
- JDM – Japanese Domestic Market
- LHD = Left Hand Drive
- LSD – Limited Slip Differential
- MAF or MAS – Mass Air-Flow Sensor
- MAP – Manifold Absolute Pressure Sensor
- MBC – Manual Boost Controller
- MIL – Malfunction Indicator Lamp (CEL)
- MT – Manual Transmission
- MY – Model Year
- NOS - Nitrous Oxide
- OBD - On Board Diagnostics
- OE – Original Equipment
- OEM – Original Equipment Manufacturer
- OL/CL - Open Loop / Closed Loop
- Pinks --certain STI parts... springs, swaybars, injectors, timing belts. Due to their color.
- Pot -- (ie. 4-pot brake) pistons on caliper.
- P&P -- port and polish of cylinder heads to improve airflow.
- PPG -- Pfitzner Performance Gearbox
- RallyX – Rallycross
- RHD = Right Hand Drive
- RPM - Revolutions Per Minute
- RSB -- Rear Sway Bar
- RWD – Rear Wheel Drive
- SOA – Subaru Of America
- SOHC – Single Overhead Camshaft
- SPT = Subaru Performance Tuning
- SWRT = Subaru World Rally Team
- STi (pre-06) / STI = Subaru Technica International
- TDC = Top Dead Center (relative to piston location)
- TMIC – Top Mount Intercooler
- TBE -- Turbo Back Exhaust
- TGV - Tumble Generator Valve
- TR - Tuner Ready (aka '06 WRX TR)
- TSB - Technical Service Bulletin
- TT – Twin Turbo
- UDP – Under Drive Pulley
- UP -- Up Pipe
- USDM -- United States Domestic Market
- VDC – Vehicle Dynamic Control
- VIN – Vehicle Identification Number
- VTD – Variable Torque Distibution
- WGA - wastegate actuator
- WHP – Wheel HorsePower
- WOT – Wide Open Throttle
- WRB = World Rally Blue
- WRC = World Rally Championship (competiton or WRC Spec cars)
Impreza Bodies:- GF = 5-door Impreza body
- GG = Impreza Wagon
- GM = 2-door (old gen) Impreza body
- GC = 4-door (old gen) Impreza body
- +
- 0 = 1.6L (not certain about this one)
- 2 = 1.8L
- 4 = 2.2L
- 6 = 2.5L
- 8 = 2.0L
- GD = New Gen Bodies
Thanks to:
Uncle Meat of the Cobb Tuning WRXForum.com, LegacyGT Forum, XimportnWRX, MidKnight, Max, Jhokur, anukaoen, nofear6235