The KFX450R has a 32-bit digital fuel injection system which
helps ensure that the engine’s performance remains consistent and is virtually
unaffected by changes in temperature or altitude. This system measures
coolant temperature, air intake temperature, air intake pressure, engine speed
and throttle position, then automatically delivers the ideal amount of fuel to
optimize power delivery.
Why can't this high-tech system deal with adding a free
flowing aftermarket pipe and/or intake?
The simple answer is that unlike automotive applications, a
fuel injected ATV does not have a mass air flow meter. Therefore, there is no
way to measure the amount of air actually taken in by the engine.
The long answer requires a bit more understanding of how a
fuel injected ATV works.
To run at the optimum level and achieve the highest power
output, Dynojet has found that an air/fuel ratio (AFR)
between 13.0 and 13.4 to 1 is best. A fuel injected ATV like the KFX450
uses a "map" that is built into the ECU to decide how much fuel to
deliver at different points of the RPM curve. Various sensors on different
systems allow the curve/map to be shifted up or
down (richer or leaner) to compensate for
altitude and air changes. These sensors do not really
change the shape of the curve they just move it
up and down a small amount.
Even if the fuel curve was perfect on a stock ATV, once you
have altered the airflow through the engine (by changing the exhaust, intake,
etc.) the table that the ECU uses to deliver the correct amount of fuel no
longer matches the altered levels of airflow at different parts of the RPM
range. One of the things to keep in mind is that not all modifications
increase airflow throughout the RPM range. Often it is necessary to lean out
certain areas of a fuel curve for peak output.
The best solution to this problem is to allow the user to add
or subtract fuel at each 250 RPM increment and throttle position so that the
new map matches the new airflow created by the addition of a pipe or intake.
Power Commander III:
The Power Commander is a fuel injection adjustment unit that
plugs "inline" with the KFX450R’s stock ECU (electronic control
unit). The PC uses original equipment style connectors, so no splicing or
cutting of the harness is required.
Changes are made to the bikes fuel via the
Power Commander's onboard microprocessor. With this technology, the PCIII offers a large area of adjustment without making any permanent changes to the
bike’s ECU. Removing the Power Commander returns the bike to its previous
stock condition. Each unit comes complete with software and cable link that
allows you to change between different maps or make adjustments to a map file.
The competition's unit can only be adjusted externally and only
modifies the length or duration of the fuel signal at low, medium and high RPM.
Fuel can only be added - there is no capability to lean the curve out.
The Power Commander can be adjusted externally for fuel delivery
at low, medium and high RPMs. The Power Commander also utilizes fuel maps that
adjust fuel delivery at every 250 RPM along the entire power curve.
Installation:
Remove Seat. Remove 2 screws that hold the side covers to the
fuel tank. Remove the 2 bolts (10mm) from the rear of the fuel tank.
Route the PCIII wire harness from the rear of the bike towards
the throttle body. Be sure to route the loom under the cross member.
Unplug the stock wiring harness from the injector which is
under the rear of the fuel tank.
Plug the PCIII wiring harness in-line of the stock wiring
harness and injector. remove the bolt that secures the stock ground
wire. Attach the ground wire from the PCIII to this same location.
Locate the stock Throttle Position Sensor (TPS)
connector. It is on the left hand side of the bike on the left side of
the throttle body.
We found the easiest way to unplug the TPS connector was to
use a screw driver through the hole in the engine mount. The clip is on
the frame side of the connector and must be pushed in to release the
connector.
This is the TPS connector after it has been removed. The
clip is on the frame side which is shown in the image above.
Maps:
The Power Commander is supplied with a KFX450R base map stored
in the microprocessor. Additional maps are available via download on www.powercommander.com
for different
pipes and intake configurations. Maps can be shared and tweaked easily over the
internet and downloaded to the Power Commander.
Using a computer, you can upload alternate maps or make changes
to the existing map using the Control Center software and USB cable supplied
with your Power Commander.
Maps can also be manipulated, stored and downloaded using the optional Power
Commander LCD Unit.
The Power Commander III LCD Unit can be hooked up temporarily or mounted on the
bike for real time data viewing.
The Power Commander LCD Unit lets you store and download maps to the PCIII.
