This data has been compiled from a few resources across the web. Feel free to add terms and edit existing terms.
- 1g
Refers to the first generation DSM that was built between 1990 and 1994.
- 2g
Refers to the second generation DSM that was built between 1995 and 1999.
- ABS - Anti-lock Braking System
A computer-controlled system that can "sense", in a braking situation,
when one or more wheels have stopped turning, yet the vehicle is still moving.
The computer will then quickly release and re-apply the brakes repeatedly, thus
giving the driver more control of the vehicle.
- AWD - All Wheel Drive
A full-time
four-wheel drive system that, on the Diamond-Star cars, is accomplished via a
torque-splitting center differential that divides the torque between the front
and rear differentials. See also: FWD, RWD.
- AWS - All Wheel Steering
A system
that actively turns the rear wheels (usually no where nearly as much as the
front wheels) in the same direction as the front wheels to aid in high-speed
cornering and to improve the overall "feel" of the car. The
Mitsubishi Galant VR-4 and 3000GT VR-4(Stealth R/T) have AWS systems.
- CAS - Crank Angle Sensor
The positional sensor on a 1G that informs the ECU what the crank and cam shaft position is for timing the ignition and injection events. There are three different types of CAS on the various 1Gs. The 90 model used optical sensors and had a pigtail to connect to the engine harness. The 91 to 93 "green top" CAS used optical sensing and an connector on the CAS body for the engine harness. The 94 cars used the "black top" CAS used hall effect sensors. See also: CKS, CPS.
- DOHC - Dual Over-Head Camshaft
The engine has two camshafts that are above the head. These engines do not have
push rods, etc., that are typical of non OHC engines (e.g. typical chevy 350).
Some DSM cars are equipped with a 2.0 L DOHC engine. Some people call it DOH "Cam",
but if you think about it, there are two Cam *shafts*, each having many lobes
(cams) - unless you have a 1-cylinder engine. See also: SOHC.
- DSM - Diamond Star Motors
A joint
effort by Mitsubishi (three diamonds) and
the Chrysler Corporation (penta-star) to
build some of the most incredible automobiles in the world. The vehicles were
produced with the names Eagle Talon, Mitsubishi Eclipse, and Plymouth Laser.
DSM cars are assembled in
Normal, Illinois.
The '94-and-up Mitsubishi Galant is also assembled at the DSM plant in IL;
previous Galant's were assembled in Japan. The Eclipse and Galant (since '89)
share the same platform.
- ECU - Engine Control Unit
The
computer that monitors and controls the various engine parameters.
- EGT - Exhaust Gas Temperature
Usually refers to a gauge that displays the temperature perceived by a sensor
that is mounted on the outside of an exhaust manifold/header/etc.
- EGR - Exhaust Gas Recirculator
An emission-control system that directs some exhaust gases back into the intake
manifold to reduce the formation of nitrous-oxide (NOx) pollutants. EGRs
typically operate off manifold vacuum, and therefore only operate in the
off-idle state up to WOT.
- EVC - Electronic Valve Control
This device is a basic closed-loop process controller. Its operation is very
similar to an electronic cruise control device. You input a desired boost level,
and it monitors the actual real time boost pressure. It then adjusts wastegate
opening to maintain a stable boost pressure (supposedly) as engine load and RPM
changes. Without a closed-loop control that incorporates an integral correction
factor, boost pressure will always vary *somewhat* depending upon engine load
and speed. The EVC isn't perfectly "tuned" for all possible
engine/turbo configurations, and it is prone to under/over correction at times.
The wastegate control is achieved by modulating a solenoid that regulates the
amount of air that reaches (and thereby opens) the wastegate.
The control module in the cockpit has controls that allow you to set
one of four different boost levels - Off, Low, High and Manual. The Manual
control has an adjustable-as-you-drive control for boost levels. The Low and
High are small pots in the back of the control unit that you set once and leave.
- FCD - Fuel-Cut Defencer
In In
Diamond Star applications, this comes with the PFC. In most
cases, it appears that you can't buy it separately. The operating principle of
the device is that of a frequency limiter. It is connected to the output of the
Air-Mass sensor pin 2 on turbo TLE's - pin 1 on Galant VR-4's). The output
frequency from the FCD tracks the input frequency until it reaches the limit
setting... the output frequency then stays the same even if the input frequency
(coming from the AMS) continues to increase. By fooling the ECU into believing
that Mass Airflow never exceeds a predetermined amount, fuel cutoff is avoided.
Unfortunately, fooling the ECU into believing the engine is consuming less air
than it really is, results in a leaned-out mixture once limiting has begun.
Because the turbo DSM's are set up to run quite rich on the top end, no harm is
done expect possibly in extreme circumstances.
(NOTE: Other "hacks" have been discovered that will serve the
same basic purpose: Removing the lower honeycomb section, enlarging the lower
AMS inlet, and adding resistors/pots to the baro sensor and thermistor circuits
are all somewhat effective techniques.)
- FWD - Front-Wheel Drive
The engine
and transmission of a vehicle transfer the power to the ground via the front
wheels. In certain high-performance vehicles, FWD also causes condition called
Torque Steer, where the vehicle tends to pull in one direction when the driver
mashes on the throttle. See also:
AWD, RWD.
- LSD - Limited-Slip Differential
A special differential that limits the amount of slip (spinning) that will occur
on a wheel that has no traction before the other wheel (with traction) begins to
move. On the AWD DSMs, the LSD unit is a viscous coupler that will shift the
torque to the wheel that has traction. Available only on the rear axle of AWD
DSMs (was not available for Galant VR-4). None of the DSMs have front LSD
units; they were determined to be unnecessary.
- MAF/MAS - Mass-Air-flow Sensor
The device used to measure volume of air being consumed by the engine. DSM cars
use a specific type of sensor called a "Karman Vortex airflow sensor".
The upper inlet of the sensor has an obstruction in the airflow path that
generates a constant stream of vortices (think of them as miniature tornadoes)
directly behind the obstruction. The velocity of the incoming airflow determines
rate at which these vortices are spun off. By placing an ultrasonic speaker and
microphone across the stream of vortices, their rate can be counted. (the
vortices spin off in alternating directions and thereby produce a alternating FM
shift of the received signal from the speaker) In addition to measuring incoming
airflow velocity, the mass airflow sensor unit also measures air temperature and
the local barometric pressure in order to provide the ECU all the data it needs
to do a true determination of the MASS of the air that the engine is consuming.
Generally speaking, Mass Airflow measurement is more precise than the
speed-density system which has been largely replaced in newer automotive
designs. Its (MAF) calibration is not affected when mods that change the engines
volumetric efficiency are performed.
- NT or N/T
Refers to the Non-Turbo version of the DSM. There were Non-Turbo 1g cars and 2g cars. The Non-Turbo 1g cars consisted of models that came with a 1.8L engine and a 2.0L 4G63 engine. The 2g Non-Turbo cars had a 420A Chrysler engine.
- PFC - Programmed Fuel Computer (also PF-CON,
FCON)
HKS sells this "piggy-back" computer, and its
purpose is to fool the stock ECU into delivering more fuel under certain
conditions. It's important to note that this "piggy-back" computer (as
they call it) does not exactly work *with* the stock ECU the way that HKS ads
might lead you to believe. The PFC doesn't share any data or address lines with
the ECU, the only connection it has is thru the lines that originally ran
directly to several engine sensors. By altering the signals from these engine
sensors, the ECU is "fooled" into delivering an different quantity
(usually more) of fuel.
There are limitations with this system, because the factory ECU it still
is in final control and has the same limitations.
It should NOT be viewed as a substitute for an self-contained engine
computer/control system. A true aftermarket engine control computer will provide
vastly greater function and flexibility. The major advantage of the PFC-FCON is
that it is fool-proof and very easy to install.
- RPM - Revolutions Per Minute
Used to state how fast an object is rotating (e.g. the crankshaft of an
internal-combustion engine). The tachometer displays the RPM of the engine of a
car.
- RWD - Rear-Wheel Drive
The engine
and transmission of a vehicle transfer the power to the ground via the rear
wheels. This method of automobile propulsion is exemplified by the Mustangs and
Camaros in your rear-view mirror. See also: FWD,
AWD.
- S-AFC
A tuning device made by Apex'i.
- SOHC - Single Over-Head Camshaft</STRONG>
An
engine with a single camshaft that is mounted over the head. Certain DSM cars
are equipped with a 1.8 L SOHC engine. See also:
<A HREF="#dohc">DOHC</A>.
- TSB - Technical Service Bulletin
Sometimes
referred to as "silent recalls". These are service notices that the
automaker sends to the dealers to notify them that certain conditions have been
experienced by a significant number of owners. They suggest actions that can be
taken to try to solve the problem. These are NOT safety recalls; the dealers
are not required to perform the service suggested by the TSB for free (or even
at all). If you know of a TSB by number, call dealers in your area to be sure
they know what you are talking about, before you just drop off your car for a
known (at least to this list) service problem. For the Diamond-Star cars:
Mitsubishi and Chrysler Corp. do NOT always issue identical TSB for the same
problems; you may have to dig a while to get your problem(s) resolved.
- VBC - Variable Boost Control
Also called MBC (Mechanical Boost Control) - A fancy name for a simple bleeder
valve. A device (air pressure regulator, aquarium valve, ice-maker valve, etc.)
that bleeds off a bit of boost pressure that is supposed to be going to the
wastegate control valve, thus delaying the opening of the wastegate.
- VPC - Vein Pressure Converter
This device allows the removal of the stock air-mass sensor. It simulates the
signal that the air-mass sensor normally supplies the computer. It uses standard
speed-density measurements to determine (estimate) the air mass being consumed.
Speed-density works by factoring together engine RPM and manifold pressure.
Barometric pressure and ambient air temperature also also fudged into the final
calculation. The calculations are highly dependent on the volumetric efficiency
of the motor. For this reason, the VPC needs to be "tuned" differently
for engines that have different levels of modifications. Many people report that
low speed operation and idle quality is adversely effected. While this is not
always the case, it is an indication of the fact that this device isn't a "plug
n' play" solution. Once the VPC is tuned to provide a reasonable facsimile
of the signals that the stock Airflow Sensor previously provided, the major
advantage of the VPC becomes apparent. The elimination of the stock
(restrictive) air-mass sensor increases incoming airflow capacity substantially.
It is credited with providing very substantial horsepower increases mainly by
virtue of the reduced intake restriction. Some advantage is also attributable to
the fact that the air-fuel mixture can be easily changed with the front panel
controls. Supposedly, the output signals from the VPC are held within a range
that won't cause the ECU to fall into a fuel-cutoff mode. (A few people report
that fuel cut problems still exist however - despite their best efforts to cure
them)
(NOTE: See the section on the PFC. The VPC is
completely separate from the stock ECU (engine computer). It doesn't (can't)
change it's programming or performance limits in any way. It merely provides the
ECU with input signals that are supposed to mimic those normally provided by the
original airflow sensor.
It consists of a pressure sensor and a temperature probe that goes into
the air-stream right before the throttle-body. There is control unit that has a
socketed EPROM that is changed depending on the car, weather the stock injectors
are installed, boost levels, etc. The control unit has a interface that plugs
into the harness between the stock computer and the wiring harness.
There are two models, the VPC and VPC-II. The II is the newer model
that does not have front panel adjustments, just a single 16 position rotary
switch. The older model, has three adjustment ranges on the front for
different RPM ranges/mixture levels. I am told if you can get the right chip in
the VPC-II it's much better than the VPC-I, but the VPC-I is better if the
chips maps do not quite match your engine.
- WOT - Wide-Open Throttle
Your right
foot (with the accelerator pedal beneath it) is firmly planted on the floorboard
of the vehicle.
