Quote:
Originally Posted by teoman
What would be needed to obtain this bsfc chart from an existing car assuming you had all of the car's canbus data?

You'd need all the data contained within those efficiency maps. Torque, RPM, and fuel consumption (HP can be derived from RPM and torque, or torque can be derived from RPM and HP).
What you would be missing is a dyno; a way to measure horsepower at a given RPM.
I'm not sure how precisely fuel consumption can be measured from the canbus either. If I understand correctly, fuel consumption is calculated based on fuel pressure, injector flow rate, and "open" time. If that's the case, you're assumptions about flow rate for a given open time would have to be fairly accurate.
Even with a dyno, you'd need to run many scenerios, such as low torque and high RPM, high torque and high RPM, and everything inbetween. And then the same for low RPM...
There has to be a way to mathematically estimate the map based on a few measurements.