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  • E10 AFR Conversion

    I called the Edelbrock tech line today and confirmed that the provided wideband O2 sensor is calibrated for pure gasoline. That said, I believe the further you go from Stoich, the more inaccurate your AFR will be if using E10 (most gas nowadays is E10: 10% ethanol).

    So bear with me:

    The O2 sensor is calibrated that 14.7 is stoich, like pure gasoline, stoich for E10 is about 14.1.

    That said, if you are running E10, it will still detect stoich as 14.7. So the ECU says 14.7, commands 14.7, but you're really getting 14.1 (if using E10).

    Now that's fine if you are commanding stoich, because the end result is the same, however the further you go from 14.7 the more inaccurate (rich) your mixture will be, I made a conversion table in Excel to visualize the difference (below). You can see in the table that 14.7 = 14.1, stoich for pure gas left, and E10 right. The problem is that if you command 12.5 for WOT, you are actually getting about 11.99 if running E10.

    So the question is, is there some magic in the ECU that can detect E10 and adjust the AFR accordingly, or should we be doing the math and adjusting the AFR for E10 in order to hit our target?
    EFI AFR E10 Conversion.jpg


  • #2
    When you get "Hard Core" about it, you use a Lambda Gauge as a reference for the fuel your using.

    So you need to install a Lambda Gauge that can switch back and forth between the 2. Then adjust the AFR accordingly.

    Link to more information: http://blog.innovatemotorsports.com/...he-difference/

    Or go to Wikipedia....I like the "extra" links on their page.
    In my neighborhood, if you open your hood to check your oil, and the vehicle still runs after you close it.......Then your labeled the Neighborhood Mechanic.
    https://forums.edelbrock.com/filedat...?photoid=42773

    Comment


    • #3
      Originally posted by BITE_ME View Post
      When you get "Hard Core" about it, you use a Lambda Gauge as a reference for the fuel your using.

      So you need to install a Lambda Gauge that can switch back and forth between the 2. Then adjust the AFR accordingly.

      Link to more information: http://blog.innovatemotorsports.com/...he-difference/

      Or go to Wikipedia....I like the "extra" links on their page.
      So the short answer is "yes".

      Lamdba = 1 = Stoich

      Pure gas lambda (1) is 14.7
      E10 lambda (1) is ~14.1

      PF4 system in stock configuration will always show lambda (1) as 14.7, so to accurately tune for E10 you'd have to convert for lamdba (1) to be 14.1, using the difference.

      14.1 / 14.7 = .9592

      That's the formula I used for the above table and should be accurate conversions for those of us running E10, which is just about everyone.

      I was wondering why my exhaust tips get black so fast. I'm commanding an idle of 13.6, which is really 13.0 because we can only get E10 in premium around here.
      Last edited by Atarchus; 06-28-2021, 01:30 PM.

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      • #4
        No.

        Pump gas is inconsistently made ( only aviation fuel is tightly regulated....you don't want planes falling out of the sky ). So you could be getting a funky mix in your E10.

        Or put another way:
        The pump could say E10. But it might be regular gas.....Hence why some new vehicles have gas type Sensors.

        A cheat sheet like you have, will get you close. But it will not be accurate.......You need a Lambda Gauge......the Bosch LSU 4.9 in the Pro-Flo 4 kit is actually a Lambda Sensor that displays AFR for convenience....just like how the MAP sensor displays vacuum vs kPa.

        Or put the best way possible:
        Americans are to dumb to understand Lambda readings ( ditto for kPa ) so we use a reference scale that the rest of the World ditched a long time ago.


        ​​​​​​

        In my neighborhood, if you open your hood to check your oil, and the vehicle still runs after you close it.......Then your labeled the Neighborhood Mechanic.
        https://forums.edelbrock.com/filedat...?photoid=42773

        Comment


        • #5
          Remember.
          Your also going to have a random amount of denaturant added with the E10: EIA Link https://www.eia.gov/tools/faqs/faq.php?id=27&t=10
          In my neighborhood, if you open your hood to check your oil, and the vehicle still runs after you close it.......Then your labeled the Neighborhood Mechanic.
          https://forums.edelbrock.com/filedat...?photoid=42773

          Comment


          • #6
            It's too bad they don't have an "advanced" option to tune in lambda, seems like that would be a much better way to tune, and safer if someone were to get a odd mix of gas.

            Comment


            • #7
              In general, most pump gas for the last 5+ Years is E10 (or E15 in a few states) unless specified as non-ethanol fuel. All ProFlo4 Development is done with 91 octane E10 (Best Standard Pump Gas in CA). There for, all Calibrations and fueling tables will be based on this fuel blend.

              As Bite_Me stated, the specific blend of fuel dispensed from the pump can vary a little bit day-to-day & station-to-station. We have not found theses fluctuations to be enough to require AFR adjustments, but the E-Tuner app does give the ability to adjust Target AFRs and monitor corrections for applications that require a bit more adjustment for various combinations & fuel blends.

              Comment


              • #8
                Originally posted by EFI Tech View Post
                In general, most pump gas for the last 5+ Years is E10 (or E15 in a few states) unless specified as non-ethanol fuel. All ProFlo4 Development is done with 91 octane E10 (Best Standard Pump Gas in CA). There for, all Calibrations and fueling tables will be based on this fuel blend.

                As Bite_Me stated, the specific blend of fuel dispensed from the pump can vary a little bit day-to-day & station-to-station. We have not found theses fluctuations to be enough to require AFR adjustments, but the E-Tuner app does give the ability to adjust Target AFRs and monitor corrections for applications that require a bit more adjustment for various combinations & fuel blends.
                Then I guess the question is, what is the software designed to recognize as lambda? 14.7 or 14.1?

                *Edit*
                reread your post, sounds like it's calibrated for E10, not pure gas as I was told on the tech line
                Last edited by Atarchus; 06-28-2021, 04:47 PM.

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                • #9
                  A PF4 user can test their fuel after fill ups to proper adjust their AFR's.

                  https://www.amazon.com/REV-X-Super-T.../dp/B073HLSVHX

                  For the concerned Customer, click on the above link : /\ /\ /\
                  Don't get too caught up in the numbers.
                  Just give the Engine what it wants &
                  Let the numbers be what they are.

                  Jim McFarland....

                  Comment


                  • #10
                    Originally posted by Atarchus View Post

                    Then I guess the question is, what is the software designed to recognize as lambda? 14.7 or 14.1?

                    *Edit*
                    reread yours post, sounds like it's calibrated for E10, not pure gas as I was told on the tech line
                    You have to remember it's a Lambda Sensor that measures air, by the "current" it's reference cell makes in reference to a "voltage".... it's not like the old sensors that made a "voltage" that you could read with a multi meter.

                    Link to Bosch Lambda sensor ( Americans call a O2 sensor ) click on "Technical Specifications", look at the 4 rows of data and remember "Please note: UA is not an output signal of the lambda sensor, but the output of the evaluation circuit. Only IP correlates with the oxygen content of the exhaust gas. Amplification factor v=17 is typically used for lean applications (lambda>1), amplification factor v=8 is typically used for rich applications (lambda<1)."...... different fuels will have different Amplifications.

                    Link: https://www.bosch-motorsport.com/con...Tabs=51877259/
                    In my neighborhood, if you open your hood to check your oil, and the vehicle still runs after you close it.......Then your labeled the Neighborhood Mechanic.
                    https://forums.edelbrock.com/filedat...?photoid=42773

                    Comment


                    • #11
                      Understood, the sensor will read lambda the same no matter what fuel source. However, that signal is either tied to 14.7 or 14.1 in the software. Meaning, sensor sends signal for lambda and the software interprets that signal as either 14.7 or 14.1 depending on how it's calibrated to the sensor. The above post makes mean believe that the software is meant to recognize lambda as 14.1 afr, though nobody has really specifically stated that. If the software recognizes 14.7 as lambda and we're running E10, then the afr displayed by the software is inaccurate.

                      *Edit*

                      Included a shot fe the E-Tuner Manual as well stating stoich is 14.7

                      Screenshot_20210628-204557.png

                      Also found this, the Edelbrock documentation on the CAN Bus output. Notice on the bottom it lists AFR (14.65), this further supports my theory that the system uses 14.65 (14.7) as lambda and is calibrated for pure gas, not E10.
                      Screenshot_20210628-201901.png
                      Last edited by Atarchus; 06-28-2021, 08:48 PM.

                      Comment


                      • #12
                        I got through your first sentence then, grazed the rest.....but I did grasp what your saying.

                        Let's start with the last part first:
                        The systems are tuned on a dyno, in a controlled environment.....Hence why the offset......the Lambda is not adjustable, but the AFR can be corrected for, or more specifically, it's "offset" for the fuel used, by using a very expensive "Reference Lambda Sensor ( AKA O2 Sensor )".......Hence why Edelbrock uses pump fuel, like you or I buy for Calibrating the "Whole" system.

                        There are hundreds of options in the Master Software that only need to be set once. Edelbrock has all ready set-up all the hard stuff. So you don't have too.....if your going to be the type of person who's going to say "But I want to set every possible option my self." Then sell your Edelbrock system, and buy a Haltech, Holley or other system that requires the use of a PC. It's the only device capable of running very complex software.
                        Edelbrock used to sell systems that required the use of a PC. But Normal People only use their phones, or tablet today. Very few people have or need a PC today. Just like no one wears watches, or has pen or paper with them.
                        We as humans have evolved away from computers as a device to own......ask any 10 year old. They want a X-Box, or PlayStation. They don't want, or need a PC.

                        If you had/have read the links I posted. You would see that 2 to 5% of the 10% used in E10 is/could be regular gasoline...... changing the AF ratio for those types of numbers means your next post would be about "Do I need to change the AF ratio for the fuel additives I just poured in the fuel tank"......Both of those scenarios have the same answer. No.

                        If your using E15. Then maybe.....some places ban the stuff. But the pumps might still have the stickers on them.

                        If E85. Then Yes. But your not supposed to run E85 in a Edelbrock EFI system.....Heck. You can't run it in their carburetors.






                        ​​​​​​
                        In my neighborhood, if you open your hood to check your oil, and the vehicle still runs after you close it.......Then your labeled the Neighborhood Mechanic.
                        https://forums.edelbrock.com/filedat...?photoid=42773

                        Comment


                        • #13
                          So basically the answer is: stop overthinking it

                          Would still be nice if they gave us the option to tune in lambda. That would ensure that the system runs at optimum performance and efficiency no matter how the gas at the pump is mixed.

                          Comment


                          • #14
                            Yes.

                            Your on your own when it comes to what you put in your fuel tank.

                            In my neighborhood, if you open your hood to check your oil, and the vehicle still runs after you close it.......Then your labeled the Neighborhood Mechanic.
                            https://forums.edelbrock.com/filedat...?photoid=42773

                            Comment


                            • #15
                              Kind of on topic, but it's about Edelbrocks #1405 Carburetor : https://forums.edelbrock.com/forum/n...hanol-gasoline
                              ​​​​​
                              In my neighborhood, if you open your hood to check your oil, and the vehicle still runs after you close it.......Then your labeled the Neighborhood Mechanic.
                              https://forums.edelbrock.com/filedat...?photoid=42773

                              Comment

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