M*00 Fuel Used output

[stevesingo]

Can I scale the fuel used output to match the fuel computer of a particular vehicle? If so, any pointers?

Steve

[RossB]

This would depend on what type of signal the computer needs to see. The Fuel Used Pulse function generates a pulse for every 0.1 unit of fuel used. This is calibrated in the Injection Setup menu by adjust ing the Fuel Used Cal parameter.

[stevesingo]

Ross,

The fuel computer uses the raw injector pulse width signal (batt V switched to earth). The fuel computer is calibrated to different models by means of a coding plug which has information for flow and number of cylinders.

Steve

[Martin]

Is your Computer input high impedance? (Im sure it must be)......Then you can just use the Injector signal itself

[stevesingo]

I can use the injector output, but the MPG will then be out as I'm using much larger injectors and I don't know how to recalibrate the OBC.

Can I configure an aux output to switch to earth with a pulswidth proportional to Inj PW, i.e a percentage of InjPW?

Steve

[Martin]

The Frequency will not vary(motec?) but you can try having an Aux table set up to RPM and Fuel Injector pulse width (Steady Frequency of 50Hz would be equivalent of 6000Rpm four stroke.) You can vary the DC on the table and try and get it as close as possible. You can manipulate DC for different RPM to make up for the increase in total injector dead time as RPM increases. (Higher RPM = more injector openings per time = more time spent in dead time zone = more total dead time)