Max power in lambda

[Randall Ross]

WOT tuning

I am currently seeing .82 lambda on wideband @ WOT. I am in Oklahoma and put 91 octane 10% ethanol blend. 93 not available. I have read that gasoline with stoich of 14.7 :1 reaches max power a @ 12.5 : 1. I have also read that a 10% ethanol blend has a 14.2 stoich. I cannot find the max power ratio for this stoich. I love math, but trying to work through the lambda equation would have been easier about 10 years ago. My question is, What kind of reading am I looking for @ WOT on 91 oct 10% ethanol?

[Randall Ross]

Did I just try to complicate something that is suppose to be the easier method? Its .85 still, right?

[eficalibrator]

The max power range will still be in the same general place in units of Lambda. You'll just be multiplying by a different reference AFR number (stoichiometry) for use with the new fuel. Like you said, don't overcomplicate it. If your engine ran best at lambda=0.82 before, I would start there with the new fuel as well.

Greg Banish
Calibrated Success, Inc.

[Randall Ross]

Thanks for the response. I leaned it up just a bit. Runs like a spotted ape. To the track in two weekends.

[gotws6]

what he said lol