Not a bad thought. With an MPGuino (which I have, but not yet installed), a tachometer and a vacuum guage (both on the to-do list), you could get a pretty decent approximation for BSFC. The torque measurement might not be perfectly precise, but if done on a very level stretch of road (ridiculous long stretches of dead flat road are kind of a speciality around here... well, within 50km of where I live, anyhow) with a warmed up car in several different gears and several throttle positions, something usefulcould probably be done with the data. Enough to do A-B testing, anyhow (still not keen on A-B-A for a header
)