MoTeC Global Forum

Had a good weekend at the races but noticed after tuning at sea level, then racing at ~4300ft elevation that the Lambda went from .85 at sea level to ~.767 range at elevation. We raced anyway and it was fun. I looked in the ECU and the Gen I Hayabusa Atmospheric Pressure Sensor (APS) is connected but it's labeled as "Fuel Pressure" in the ECU on AV4 input and the sensor has a custom table.

Is there a preset config for the stock Hayabusa Atmospheric Pressure Sensor?
When I set AV4 input to read the stock Busa APS, what do I need to do to tell the M84 that I want it to compensate the fuel table for changes in atmospheric pressure? Comp1 in the Fuel Compensations is locked to EGT and Comp2 is locked to User Channel 2 when I right click and select Axis Setup.

It looks like the "Fuel Pressure" compensation is locked to "Fuel Pressure" in the axis setup and that one is AV4 which is actually my Baro sensor on the Busa so maybe I just use that?

We set a new class record at 202.5mph in the dirt! Thinking of how fast we could have been with the Lambda dialed!

I think you need to wire your APS to AV8 (User 1), then change the name to "APS" (Adjust->Sensor Setup...->Input Setup...->Other (then click Change on User 1). This can be used as the Y axis of the Fuel Comp 1 (don't enable the X-axis unless you need to). User 2 is connected to an AT input and probably is unsuitable for the APS.

If the calibration for AV4 seems correct for your sensor (ie, it reads the same as your map sensor when the engine is stopped), then I would use that for the AV8 input.

Normally a compensation table for atmospheric pressure would be:
0 kPa = -100%
100 kPa = 0%