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Old 12-30-2015, 01:51 PM   #47 (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: 66.42 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
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Originally Posted by MichaelRTJ View Post
I could see the benefit on a very short trip, or a relatively short on a cold winter day. But other than that, it doesn't seem to have any advantages.
IDK if this has come up in this thread, but a standard line here has been that a WAI reduces pumping losses. The ECU adjusts AFR, so the mix won't become lean as the warmer, thinner air gets pumped into the engine. But less mass of air means less fuel too... that means you get less fuel/air at a given throttle position. Therefore to accomplish the same power you open the throttleplate further, reducing the parasitic losses caused by the engine trying to suck air/fuel in past the throttle plate.

So the warmer the engine, the warmer the air, the better the reduction in pumping losses. Therefore, I'd guess short trips will not see a benefit, unless IAT climbs high, fast, somehow.

IDK if a WAI can help warmups... maybe?
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.

Last edited by California98Civic; 12-30-2015 at 01:53 PM.. Reason: typos
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