Quote:
Originally Posted by jmcc
For back to back under controlled conditions maybe. Question was about generating a BSFC map and the errors in the fuel calculation in the ECU make this too inaccurate to be useable (in my opinion).
Reason for inaccuracy: fuel flow is calculated as a function of rail pressure and injection duration for a nominal injector. Injector flow particularly will vary, and needle lift vs electrical pulse will also be inconsistent.
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OBD is accurate, but not precise.
What are you going to do with BSFC once you know it on a chassis or engine dyno?
Probably try to figure out most optimal engine parameters to run the engine at.
But you would need to compare that to precise measurements of the aerodynamics of the car, which would require a lot of time in a wind tunnel with a moving floor.
Another option is to drive your car down the road with a MPGUino and learn where your car gets the best MPG.
Sure it won't be PRECISE, but it will be hella accurate.