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Old 09-27-2010, 06:03 PM   #6 (permalink)
UFO
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Quote:
Originally Posted by autoteach View Post
You cannot use fuel injector duty cycle by itself for figuring out fuel consumption. As someone said above, the opening and closing affects the actual open time. The other part that you are overlooking is the fuel pressure. There are very few cars on the road that use steady state fuel pressure, so figuring out flow will be tough. As for using engine load, that is different, although, still unable to tell you consumption without a BSFC map.
All the fuel injection systems I've worked on have constant fuel pressure across the injector. And there are of course opening and closing times that add error into using the duty cycle as linear, but as long as you are using mid-range duty cycles, the error is manageable for a relative calculation.
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