Quote:
Originally Posted by jimepting
A single full power pull traces a pattern across a portion of the BSFC contour.
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Correct, kind of. This contour that you speak of is just a single line across the top of the operating range on the chart, as others have noted.
Quote:
Originally Posted by jimepting
...BSFC data is for full throttle and that is virtually never the situation when one is attempting to find the best fuel economy.
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This is wrong. BSFC = brake specific fuel consumption. In layman's terms this means fuel consumed per unit of power produced. You still have a value for this when the engine is at part throttle. The contour plots that are often posted here are in fact values of BSFC across the entire operating range of the engine, zero to full throttle from idle to redline. Obviously this could encompass an enormous amount of data points. But generally speaking you only need to map the engine at a handful of load points (okay maybe a dozen), every 100 rpm or so. Then toss the data in excel or matlab and crank out a contour plot. If you are looking for max efficiency of your engine this is not a hard thing to do for the quality of data that you'll get.
Test drive, whether the engine in the BSFC chart you posted was at WOT is not a function of engine rpm. If you reference the top line of the data range, that is exactly what those two circle data points are, at WOT. The chart contains all data from zero load to full load across the entire rpm range of the engine. The vertical axis is engine load (torque). We need a more solid BSFC explanation thread that we can link to. Maybe I'll start drafting one.
Any type of sensor that generates a voltage or current signal can be used to measure a given parameter of engine operation... as long as you know how to interpret the data. If you have equipment to measure cylinder pressure, its an extremely valuable tuning tool, though not easy to acquire.
Obviously its a little tricky to pull an engine from a vehicle just to throw it on a dyno stand. But if you're building up a project car, repairing a bad wreck, etc, why not set it up on the dyno to shake it down? Much easier than finding problems later in the vehicle.
Congrats on the dyno acquisition, hope to see some data posted here some day.