Jump to content

Instantaneous Fuel Consumption


Recommended Posts

I'm trying to get a limited fuel warning that will calculate total fuel remaining in my cell and if my burn rate is too high to allow me to finish an event by bring up an alert. I realize that this is currently beyond the G4 plus extreme I'm running (and should be) however given I can CAN Bus this to my raspberry pi then calculate total burn and distance remaining I can generate this logic myself. My problem is this, my engine is rotary and doesn't meet the criteria for Instantaneous Fuel Consumption. 


The Instantaneous Fuel Consumption is a calculated number that has the following requirements:

·Only one injector per cylinder (no staged injection).
·Only works on Injection Modes that inject once per cylinder per 720 degrees of crankshaft revolution.
·Four stroke engines only.
·The Engine Capacity must be accurate.
·The Injector Flow must be accurate.




Again I realize that, given some assistance, I could create a string of CAN Bus data from which I could possibly calculate the Instantaneous Fuel Consumption, however completing this logic in ECU will certainly give me a considerably better starting point from which to calculate my total burn. 





Edited by redmist
Link to comment
Share on other sites

The answer is helmholtz Shooting flames with a rotary engine :D

I dont think the provided instant fuel value would be much use in your scenario, because it gives a litres per km result that relies on a wheelspeed DI input for the km part of the equation.
Which I'm imagining will be wildly inaccurate in the case of a big HP rotary driving on dirt!

It sounds like a litres per minute figure is what you'd be after instead, you can probably get a good enough approximation of this from datalogging Effective Injector Pulsewidth.

Edited by Davidv
Link to comment
Share on other sites

The answer is helmholtz Shooting flames with a rotary engine :D

The guffaws could he heard outside my house!!! ;)

Hadn't realized that Instantaneous Fuel Consumption was burn l/km which isn't as much help as I had envisaged. I do have provision for 4 wheel speed sensors and have two GPS devices (Aim Evo4 and Raspberry Pi 2) in the Tatum. However it looks like I'll have to calculate fuel burn based on Effective Injector Pulsewidth, the flow of the primary and secondary injectors and fuel pressure..... I wonder how accurate simply adding up the effective injector pulse-width sample say 1hz and deducting it from a known numeric total injector pulse width per tank. If it's accurate enough it'll simplify the math slightly and allow the pi more clock cycles to deal with Can Bus data and paddle shifter calculations.
You would think a project manager would have a better sense of feature creep and how to kill it. Guess I'm too connected... 


Edited by redmist
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...