Results 1 to 8 of 8

Thread: Flex Fuel Question

  1. #1
    Tuner in Training
    Join Date
    Jun 2011
    Posts
    36

    Flex Fuel Question

    Just going through the Tuning Shool book on Flex Fuel Tuning, when adding a flex fuel sensor and selecting "sensor" in the drop down menu for flex fuel, the book doesn't touch on how to set up the Stoich table. It has you fix up the PE Spark Advance Correction Mult vs Composition table. I read somewhere to set the Stoich table to gas settings all the way accross, that would leave your EQ ratio the same no matter how much alcohol it's seeing. I can't find anything more on this, so do I need to set up the Stoich table for flex fuel or just leave it gas all the way? Thanks.

  2. #2
    Senior Tuner Ben Charles's Avatar
    Join Date
    Aug 2009
    Location
    Calibrating
    Posts
    3,371
    Setup stoich as a flex fuel vehicle!!! Stoich is a multiplier if fuel.. so we don’t want ethanol targeting 14.x stoich ratio

    Email Tunes, [email protected]
    96 TA Blown/Stroked, 4L80E/Fab 9
    15 C7 A8 H/C 2.3 Blower/PI
    14 Gen 5 Viper
    Custom Mid Engine chassis, AKA GalBen C

  3. #3
    Tuner in Training
    Join Date
    Jun 2011
    Posts
    36
    Quote Originally Posted by Ben Charles View Post
    Setup stoich as a flex fuel vehicle!!! Stoich is a multiplier if fuel.. so we don’t want ethanol targeting 14.x stoich ratio
    I agree. Here's a copy and paste of what the write up says and the link also:

    Fuel params:
    - open loop tables and PE tables on newer OS's blend between gas and alcohol tables using blend factor below
    - blend f*actor 0 is gas table, 1 is alcohol, 0.5 is middle, you get the idea. (usually this has values in it, again fix if all 0's)
    - Note: if your stoich table has a flex fuel cal in here you need to set it to something constant across the whole table (ie. gas numbers) otherwise as you change the freq, the stoich will change.
    - obviously you need to be open loop for the fuel stuff to work.

    https://www.g8board.com/forums/115-i...uel-setup.html

  4. #4
    Senior Tuner Ben Charles's Avatar
    Join Date
    Aug 2009
    Location
    Calibrating
    Posts
    3,371
    I didn’t look at the write up.. but some of what you posted is incorrect

    Email Tunes, [email protected]
    96 TA Blown/Stroked, 4L80E/Fab 9
    15 C7 A8 H/C 2.3 Blower/PI
    14 Gen 5 Viper
    Custom Mid Engine chassis, AKA GalBen C

  5. #5
    Tuner in Training
    Join Date
    Jun 2011
    Posts
    36
    Quote Originally Posted by Ben Charles View Post
    I didn’t look at the write up.. but some of what you posted is incorrect
    Out the window it goes then. Thanks Ben.

  6. #6
    Senior Tuner
    Join Date
    Jan 2014
    Location
    Australia
    Posts
    1,970
    yep checked the write up and yea thats bad info but nobody corrects it, best to find a factory flex tune and copy over what suits and adjust timing to suit your engine

  7. #7
    Tuner in Training
    Join Date
    Jun 2011
    Posts
    36
    Quote Originally Posted by 07GTS View Post
    yep checked the write up and yea thats bad info but nobody corrects it, best to find a factory flex tune and copy over what suits and adjust timing to suit your engine
    Yeah sometimes these internet folk can throw you off. That’s why i asked, something was off about it for sure. I’ve got it handled now, thanks for the input.

  8. #8
    Potential Tuner
    Join Date
    Mar 2019
    Location
    Illinois
    Posts
    1
    Quote Originally Posted by EmmerichLSx View Post
    Just going through the Tuning Shool book on Flex Fuel Tuning, when adding a flex fuel sensor and selecting "sensor" in the drop down menu for flex fuel, the book doesn't touch on how to set up the Stoich table. It has you fix up the PE Spark Advance Correction Mult vs Composition table. I read somewhere to set the Stoich table to gas settings all the way accross, that would leave your EQ ratio the same no matter how much alcohol it's seeing. I can't find anything more on this, so do I need to set up the Stoich table for flex fuel or just leave it gas all the way? Thanks.
    Emmerich LSX, I'd be very interested to her you feedback after reading through the Tuning School "GM Advanced" book that includes Flex Fuel tuning. I've got the other three GM GenIV books, but have been holding off on this one until after my class with them next month.