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Old 09-14-2023, 07:52 PM   #76 (permalink)
Ecky
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Quote:
Originally Posted by djr48312 View Post
Gasoline can cruise lean as you say but shouldn't E85 be able to go to a leaner lambda value?
I'm not certain, and I'd like to hear what others have to say on the topic.

Gasoline isn't knock limited going lean. Once you get past maybe lambda 1.05 or so, combustion temperature drops and emissions start to get clean (NOx drops). Catalysts don't work at this ratio.

At around lambda 1.3, most normal AFR sensors cease to read actually, which is what has always stopped me from running leaner. Honda uses sensors in their lean burn cars that read accurately to at least lambda 1.5, and the combustion chambers in those cars are able to combust at those ratios efficiently and reliably. I'm uncertain if ethanol can actually combust leaner, but it might just buy virtue of having more fuel per amount of air.
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