HONDA
BIG RED
FUEL INJECTION:
BUILT FOR
THE REAL
WORLD |
A key element in this engine’s consistent
and convenient performance is Honda’s programmed
fuel injection system (PGM-FI). Big Red’s
PGM-FI system uses a 40mm throttle body and a
high-tech 12-hole fuel injector to maximize fuel
atomization. In general, fuel injection provides
Big Red the ability to adjust to real-world variables
in a seamless, automatic fashion—all of
which make the driving experience that much more
effortless. Beginning with a marked increase in
power output, some other benefits include crisp
throttle response; improved fuel consumption;
the elimination of the choke circuitry for easy
cold starting; automatic altitude compensation
to 12,000 feet; automatic temperature compensation
from -13° to +104° Fahrenheit; faster
engine warm-up; and smoother idle control, thanks
to the Idle Air Control Valve (IACV), which establishes
a basic idle setting of 1400 rpm, plus or minus
50 rpm.
Essentially, this system monitors several variables
to control the injected fuel quantity. PGM-FI
is a mapped injection system, meaning that the
basic variables of engine speed and throttle
angle are used to determine mapping. Based mainly
on those measurements, the system looks to the
Electronic Control Module (ECM) for precise
fuel delivery. The ECM adjusts fuel delivery
according to four additional variables: intake-port
pressure, enginecoolant temperature, intake-air
temperature and atmospheric pressure. This fuel-delivery
recalculation process is repeated many times
per second to ensure the correct mixture for
conditions and to provide optimal performance
and remarkably crisp throttle response over
a wide operating range.
HONDA
TRUE AUTOMOTIVE-STYLE
AUTOMATIC TRANSMISSION
|
For a familiar driving experience, Big Red incorporates
an automotive-style transmission. This system
features a hydraulic torque converter, three hydraulic
clutches and an ECM to automatically select one
of three forward gears or, as you choose, reverse.
Among all ATV and Multipurpose Utility Vehicle
(MUV) manufacturers, Honda alone boasts the
only true automotive-style automatic transmission.
Though Big Red’s unit features several
innovations that cater specifically to MUV application,
the torque converter used in this system operates
in principle much like the torque converters
used in trucks and automobiles. Basically, it
links the engine to the automatic transmission
much like a manual clutch connects an engine
to a manual gearbox. Both systems drive the
vehicle and they also come into play when the
vehicle stops.
With a manual transmission, manual actuation
of the clutch temporarily disengages the engine
from the transmission when coming to a stop.
In similar fashion, Big Red’s torque converter
performs this connect/disconnect function automatically
as needed. A torque converter can accomplish
this because it is a fluid coupling, rather
than a solid coupling. At low engine speeds,
the torque converter slips internally, which
allows the engine to spin independently of the
transmission. As a result, the engine of the
stopped vehicle is allowed to run at idle while
the transmission is in gear. When it’s
time to roll, the driver simply steps on the
pedal to increase engine speed, and the torque
converter then transfers power to the transmission
to make the vehicle move.
