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Thread: E-85 Stociometric Reading On Wideband A/F Gauge

  1. #1
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    E-85 Stociometric Reading On Wideband A/F Gauge

    Hello. I have a question about the A/F ratio readings I'm getting running 68% ethanol, according to VCM scanner. In open loop, my autometer sport comp. shows 14.7:1. In PE. mode it's around 13:1. Am I missing something here? Why would it be that lean in open loop? Any thoughts on this would be greatly appreciated.

  2. #2
    Tuning Addict 5FDP's Avatar
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    Because it's still reading on the gas scale and your open loop for gas is still going to be 14.7ish.

    Tune in lambda if you want to run E85.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
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    Lambda does simplify things, but air fuel comes from lambda readings, so nothing wrong with using them... You just have to realize that because your commanding different stoichiometric values doesn't mean that the car is going to run at those values - they're only there so the ecm can adjust the quantity of fuel to achieve the same burn... You can even keep using air fuel error with some work to the math equation for the changing stoichiometric and alcohol values...
    2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
    2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80

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  4. #4
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    Quote Originally Posted by Blackhawks1 View Post
    Hello. I have a question about the A/F ratio readings I'm getting running 68% ethanol, according to VCM scanner. In open loop, my autometer sport comp. shows 14.7:1. In PE. mode it's around 13:1. Am I missing something here? Why would it be that lean in open loop? Any thoughts on this would be greatly appreciated.
    Lambda lambda lambda. Widebands don't actually read AFR.

    /deadhorse

  5. #5
    Tuner in Training b2319dragracer's Avatar
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    So how do I make my readings in Lambda?

  6. #6
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    Change the transform for the external input.