05 - FIM03 Fuel Flow Modes
FIM03 features a dedicated fuel flow function using channels 2 & 3 which allow the module to automatically scale and create the following fuel flow related channels:
- Fuel used (L,Gal) – Channel 2
- Fuel flow rate (L/Hr, Gal/Hr) – Channel 3
In addition two internally calculated channels are generated:
- Fuel consumption rate (L/100 km) – Channel 5
- Fuel consumption rate (km/L, MPG) – Channel 6
Channels 2 and 3 must be connected to the fuel flow sensor. In this output mode two new channels 5 and 6 are created for the fuel consumption channels. FIM03 must be connected in the following way to be able to output all of the channels listed above:
Channel 2 input is dedicated to a fuel used measurement.
Channel 3 input is dedicated to a fuel rate measurement.
Note: Channel 3 must be connected to the fuel flow input when fuel consumption data is required, e.g. km/l and L/100 km
Fuel Used – Channel 2
Fuel Flow – Channel 3
Note: Fuel consumption rate can only be calculated if a speed source is selected.
Fuel Consumption Rates (Channels 5 & 6)
FIM03 will only generate the fuel rate data for channels 5 & 6 if channel 3 is connected to a fuel flow sensor and configured correctly as above. In addition, if FIM03 is being used with a Racelogic VBOX the speed source must be set to ‘Speed on VBOX CAN ID 0x302’. If using any other speed source then ‘Speed on Channel 4’ must be selected.
Note: When Channel 4 Is used as the speed source it must be configured to measure speed in km/h, otherwise the Fuel Consumption rates on Channels 5 & 6 will be wrong.
Using an alternative speed source for fuel flow measurement on the FIM03.
Speed is required by the FIM03 to calculate the Fuel Consumption rates. In most cases this will come from the VBOX via the existing CAN connection. If it is required to use a speed source other than that from the connected VBOX, Channel 4 of the FIM03 can be set to be the speed source for the calculation of the internal channels (5&6).
In the graph below taken from VBOX Tools, fuel used is displayed in green.
Fuel flow rate (L/100 km) is displayed in blue.
Speed is displayed in red and RPM in brown.
The flow rate can be seen at a high level as the vehicle is accelerating and the RPM climbs. As the RPM drops because the throttle pedal has been lifted, the flow rate drops to zero in line with then the fuel injectors stop injecting.
The fuel used line can be seen rising in line with the fuel flow rate.