12A engine designation of all 2 rotor engines with 1200cc of displacement; engines were all made from 1985 and prior
13B engine designation of all 2 rotor engines with 1308cc of displacement
20B engine designation of 3 rotor engines that were only offered in Japan-only Mazda Eunos Cosmos; stock 20B's in Mazda Eunos Cosmos were all twin, sequential turbo and mated only to automatic transmissions
ACV "Air Control Valve" - one of the primary air control units for emissions; located right above the turbocharger
AFAIK "As Far As I Know"
AFK "Away From Keyboard"
AFC "Air-flow Converter" - usually referenced to the A'PEXi S-AFC; this electronic unit can modify fuel delivery curves; see our "Fuel Computers" section in Tech | Mods | Electronics for more details
AFM "Airflow Meter" - primary metering sensor component that detects the amount of air entering the engine; also known as MAF (mass airflow meter) or MAS (mass air sensor)
AFR "Air/Fuel Ratio" - term usually used with the word "gauge; used to describe the ratio of air to fuel in the intake charge mixture
AIC "Additional Injector Controller" - electronic unit that can control additional fuel injectors added into the intake; HKS uses the "AIC" moniker
AIT "Air Intake Temperature" - term usually used with the word "sensor"; the AIT sensor monitors intake charge temperatures, and relays signal back to the ECU
A'PEXi "A'PEX integration" - Japan aftermarket sutomotive tuners that offer a wide range of products for most Japanese vehicles; founders of A'PEXi were ex-employees of HKS (see HKS); U.S. website > http://www.apexi-usa.com/; Japan website > http://www.apexi.co.jp
ATDC "After Top Dead Center" - referenced in degrees, it's the relative position after TDC; see related "TDC" and "BTDC"
BAC "Bypass Air Control" valve - primary air bypass valve that controls idle on the engine against varying engine loads
bar unit of pressure used to describe boost; 1 bar = 14.5 psi; also see kg/cm²
BBIAB "Be Back In A Bit"
BBL "Be Back Later"
BOV "Blow-Off Valve" - intake relief valve that opens up when engine is under boost and throttle plates are shut abruptly, like under shifting; if excess boost isn't relieved, the pressure will back up to the turbo compressor causing an undesirable condition called compressor surge - compressor surge will cause damage to the turbo!
BTDC "Before Top Dead Center" - referenced in degrees, it's the relative position before TDC; see related "TDC" and "ATDC"
BTW "By The Way"
CARB Not short for "carberator", but an acronym for the "California Air Resouce Board"; this particular CARB initiates the strictest guidelines for air quality in the state of California; CARB controls all aspects of automotive emissions testing in the state of California
CARB EO CARB "Executive Order" - all aftermarket automotive parts that have a CARB EO number have been subjected to (and passed) rigorous automotive emissions testing by CARB themselves; a CARB EO # allows aftermarket components to (easily) pass a visual test when undergoing an extensive emissions test in the state of California; see related "CARB"
CBV "Compressor Bypass Valve" - what Mazda calls the stock BOV; see "BOV"
CHRA "Center Housing and Rotating Assembly" - turbocharger term used to describe the center housing, shaft, turbine wheel, and compressor wheel assembly; this basically describes the whole turbo minus the turbine and compressor housings
CPU For the FC3S, it uses a CPU to control:  horn, hazard lights, turn signals; a common component that has cold solder joints that crack and fail, rendering the horn (usually) inoperable
DIY "Do It Yourself"
DTSS "Dynamic Tracking and Stabilizing Suspension" - designed into all FC3S models, this rear passive steering system controls toe settings depending on load to the rear tires
DOT "Department of Transportation" - U.S. governing body that controls all aspects of highway travelling; lighting lenses are embossed with "DOT" to certify them for safe use on U.S. roads; brake fluids are also graded with a "DOT" scale - always use DOT3/DOT4 minimum rated brake fluid
EBC "Electronic Boost Controller" - any number of electronic units used to control boost on a turbocharged engine via a solenoid valve on the wastegate vacuum hose
ECU "Engine Control Unit"/"Engine Computer Unit" - main computer that controls all facets of the engine
EGR "Exhaust Gas Recirculating" valve - critical emissions control valve; located on the back of the lower intake manifold, it recirculates exhaust gases into the intake charge to keep combustion temperatures low
EGT "Exhaust Gas Temperature" - usually used with the word "gauge"; describes the heat of the exhaust that's exiting the engine
EMS "Engine Management System" - used to describe any electronic unit that can control either fuel delivery or ignition timing or both; usually used to describe a stand-alone, aftermarket computer; see related "ECU"
EVC "Electronic Valve Controller" - HKS line of electronic boost controllers
FC shortened form of "FC3S"; see "FC3S"
FCD "Fuel-Cut Defensor" - electrical unit used to prevent programmed over-boost fuel-cut in the stock ECU; the FCD is usually spliced into the boost sensor and modifies it's signal
F-CON Short for the HKS PFC F-CON, this unit is able to adjust fuel delivery via a piggy-back computer unit that attaches to the stock engine harness and ECU via plug-through connectors
FC3S Mazda internal code name for the 2nd generation RX-7 made from 1986-1991 in the U.S.; Japan automotive enthusiasts also use this nomenclature
FD shortened form of "FD3S"; see "FD3S"
FD3S Mazda internal code name for the 3rd generation RX-7 made from 1993-1995 in the U.S.; Japan automotive enthusiasts also use this nomenclature
FMIC "Front-mount Intercooler" - aftermarket intercooler installed in the front bumper
FSM "Factory Service Manual" - official reference material the (Mazda) manufacturer uses for repair; contains all material relavant to the vehicle regarding specifications, repair, and maintenance; available from the (Mazda) dealer
FWIW "For What It's Worth"
FYI "For Your Information"
GCC "Graphic Computer Controller" - HKS line of electronics that allows RPM-based control of other HKS electronic components
HKS Famed Japan tuner company; the letters "HKS" stands for the co-founders and company names:  Hasegawa-san, Kitagawa-san, and the Sigma Company; U.S. website > http://www.hks-usa.com; Japan website > http://www.hks-power.com
HP "Horsepower" - fundamental unit of power in the U.S.; see related "PS"
IAT "Intake Air Temperature" Sensor - sensor which signals intake temperature back to the ECU; located on the throttle body "cap" right before the throttle body itself
IHI "Ishikawashima Harima Industrial" - manufacturer of turbochargers, most notably those kits for A'PEXi
IMHO "In My Honest Opinion"
IMO "In My Opinion"
kg/cm² unit of pressure used to describe boost; 1 kg/cm² = 14.2 psi; also see "bar"; a lot of Japan boost gauges use this unit
KKK "Kuhnle, Kopp & Kausch" - Famed European turbocharger manufacturer; recently changed name to "KKR"
KKR Famed European turbocharger manufacturer; see "KKK"
Kouki Japanese word loosely translated as "after"; denotes RX-7s (in this case) after the minor/model change, which covers 1989-1991 models; term is commonly used by Japanese auto enthusiats; see related "Zenki"
LIM "Lower Intake Manifold" - the 13B intake manifold is divided into two pieces - the lower section mates with the engine block itself; see related "UIM"
LSD "Limited Slip Differential" - component located in the rear differential that allows left versus right tire slippage when turning but locks up (i.e. left and right side tires) under "demanding" conditions especially when power is being applied; this is desirable for superior traction
LOL "Laughing Out Loud"
MAF "Mass Airflow" meter - see "AFM"
MAP "Manifold Absolute Pressure" sensor - a fancy name to call a pressure sensor; also used to describe a type of engine load-sensing ECU system
MAS "Mass Air(flow) Sensor" - see "AFM"
MIG "Metal Inert Gas" - welding technique usually for mild steel applications; this welding technique is very quick and cheap, unlike TIG welding; see related "TIG"
MOP "Metering Oil Pump" - see "OMP"
NOS More widely known for being "Nitrous Oxide Systems", old domestic V8 enthusiasts use this acronym to stand for "New Old Stock"; "New Old Stock" stands for original automotive parts that have been kept stashed away for many years and then recently uncovered or found (by choice or accidently)
OEM "Original Equipment Manufacturer" - refers to a stock, (Mazda) dealer item
OMP "Oil Metering Pump" - Mazda uses an oil injection system that injects engine motor oil into the combustion chamber.  The OMP is the main controlling unit that dictates how much oil should be injected.
OT "Off Topic"
OTOH "On The Other Hand"
PITA "Pain In The Ass"
PS "Pferdestärke" - German equivalent to "horsepower"; "PS" unit is used almost exclusively by Japanese automakers and Japanese auto enthusiasts; 1hp = 1.01387ps; 1ps = 0.98632hp
PST "Pipe Sealant with Teflon" - paste thread sealant; "PST" is a brand name by Permatex
ROFL "Rolling On Floor Laughing"
RPM "Revolutions Per Minute" - usually used to describe speed of the engine turning; one RPM = one full revolution of the engine "crankshaft" or eccentric shaft on a rotary engine
RTV "Room Temperature Vulcanizing" silicone - a fast-curing sealant used in engine components assembly; use only "automotive/O2 sensor safe" silicone sealants, as this does not contain acetic acid which can harm O2 sensors
SEMA "Specialty Equipment Manufacturing Association" - industry association that governs the automotive aftermarket industry; website > http://www.sema.org/
SST "Special Service Tool" - used by Mazda dealers for specialized work
SSR "Speed Star Racing" - one of the top rim manufacturers in Japan
TB "Throttle Body" - primary component that controls the amount of air that enters the engine via butterfly plates
TDC "Top Dead Center" - used to describe when the engine's "#1" rotor (or piston) is at the peak/highest of it's compression cycle; see related BTDC/ATDC
TID "Turbo Inlet Duct" - stock, black, rubber duct that connects the AFM to the turbo itself; stock TID tends to crack and lead to intake vacuum leaks
TIG "Tungsten Inert Gas" - a specialized and expensive welding technique, usually for chrome-moly, stainless steel, and aluminum; this time-consuming welding technique produces very nice and neat welds; see related "MIG"
Torsen (LSD) Short for "torque sensing", this particular type of LSD is the most linearly locking of all the various LSD types; the "Torsen" name is owned by the Zexel-Gleason company; see related "LSD"
TPS "Throttle Position Sensor" - sensor used to measure the amount of throttle input back to the ECU; located on the throttle body front-side
TSB "Technical Service Bulletin" - internal Mazda memo for Mazda dealerships that provide tips for problems; note:  dealers are not required to acknowledge TSB's to customers who are aware of them
UIM "Upper Intake Manifold" - intake manifold is divided into two pieces - the upper intake manifold is directly after the throttle body; see related "LIM"
WAG "Wild Ass Guess"
WG "wastegate" - primary component that controls boost levels on a turbo
WOT "Wide Open Throttle" - term used to describe the throttle (plates) being fully open or the gas pedal being fully depressed
Zenki Japanese word loosely translated as "before"; denotes RX-7s (in this case before the minor/model change, which covers 1986-1988 models; term is commonly used by Japanese auto enthusiats; see related "Kouki"

Questions?  Comments?  Send mail to:  reted(at)fc3spro.com