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Old 06-13-2018, 10:21 PM   #9 (permalink)
Cyborg ECU
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Join Date: Mar 2011
Location: Coastal Southern California
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Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 59.86 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
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Originally Posted by 19bonestock88 View Post
I wish that were my BSFC map, but I have the 2.2L Ecotec thatís also found in the Malibu, Cobalt, Cavalier, etc...
Ah. I also don't have a map for my specific engine, either. But I always do pulses at 75%-80% load in the best gear to keep me 1700-2200 RPM (sometimes 1500 and sometimes 2500). There is a general lesson from reading multiple BSFC maps for NA gasoline engines and that is that the 75% load, maybe 80%, from 1700 RPM, maybe 1500, up to maybe 2500 RPM is the area of best BSFC. And if that is not the exact best in my car, it would be damned close. Then I can experiment.

I think the general lesson might be that you could be leaving some potential untapped with the 40-50% load, high gear acceleration you described. On the map I posted above--and some others--50% load at 1000 rpm is in the 325 band, whereas if you down shifted and hit 75% load at maybe 2500 rpm you would be in the 250 island. That is maybe 20% more efficient. I got that right, yes?

See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.

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