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How to Datalog and Submit Your Project File

  • Updated

Your eFlexTuner software can datalog all eFlexFuel fueling parameters. This can be helpful in troubleshooting or creating a custom fueling tune for your vehicle. This article will show you how to datalog and submit an eFlexFuel project file, which contains the datalog.

If you have an eFlexPro2 with an aftermarket wideband connected to your harness, your datalog will include your Air-Fuel exhaust data, allowing you to create a custom fueling tune. Read the article "How to connect an Aftermarket Wideband (Ex. AEM X-Series) to the eFlexPro Harness" for additional information: https://support.eflexfuel.com/hc/en-us/articles/15857293217052 

Step 1: Connect your eFlexTuner software while your vehicle is running. If you are having Bluetooth connection issues, refer to this article: https://support.eflexfuel.com/hc/en-us/articles/16101881615132 

Step 2: Confirm your connection before logging. If you see "eFlexFuel Connected" highlighted in green in the bottom left of the eFlexTuner window, you may proceed. 

Step 2: Select the "Log" tab above the eFlexTuner fuel map window.

Step 3: Click the circular "Record" button at the bottom of the log window.

NOTE: All eFlexFuel parameters will be logged during your datalog. You can select different parameters to view while logging by clicking the gear icon at the right of the icons.

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Step 4: After your datalog is complete, save your Project File on your laptop.

You can now email your vehicle's Project File (.efp) which will include your vehicle calibration and datalog. The .efp file can be found by opening the eFlexTuner folder (wherever you have it saved), and entering the Projects folder:

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Step 5: Email your Project File (.efp) to support@eflexFuel.com and include your full name, vehicle details, and vehicle modifications. Include the reason for sending your project file (custom tune request, troubleshooting, etc.) along with any description or details that are relevant.

AFR Vs. Lambda Overview

AFR (Air-Fuel Ratio) and lambda are two different ways of measuring the air-fuel mixture in an engine. Here's a simple explanation of the key differences:

Air-Fuel Ratio (AFR)

AFR represents the mass ratio of air to fuel in the engine's combustion mixture. For gasoline, the stoichiometric (ideal) AFR is typically 14.7:1, meaning 14.7 parts air to 1 part fuel by mass. In oversimplified terms, AFR is calculated by multiplying the lambda output from your O2 sensor (O2, CO, CO2 and HC) by a fuel's stoichiometric AFR. AFR gauges are typically set by default to stoichiometric 14.7 for gasoline, thus the "actual AFRs" displayed are only accurate for gasoline. Since the stoichiometric AFR differs for all fuel types, this formula will change depending on fuel type.

Lambda

Lambda is another way to display air-fuel ratio but is simpler than AFR. Lambda is calculated directly from the output from your O2 sensor (O2, CO, CO2 and HC), without an additional formula based on fuel type. This means that lambda is a consistent measure of O2 sensor output and reliably reports the air fuel ratio regardless of ethanol %. A lambda value of 1.0 always indicates the stoichiometric mixture, regardless of the fuel type.

Key Differences

  1. Measurement scale:
    • AFR uses absolute values that will differ by fuel type (e.g., 14.7:1 for gasoline)
    • Lambda uses a relative scale where 1.0 is always stoichiometric
  2. Fuel compatibility:
    • AFR values vary for different fuels
    • Lambda values are consistent across fuel types
  3. Richness/leanness interpretation:
    • For AFR, lower values indicate a richer mixture
    • For lambda, values below 1.0 indicate a richer mixture, above 1.0 indicate a leaner mixture
  4. Calculations:
    • Lambda is calculated from O2 sensor outputs (combinations of O2, CO, CO2, HC)
    • AFR is calculated by multiplying O2 sensor outputs (combinations of O2, CO, CO2, HC) by a specific fuel's stoichiometric AFR.
    • In other words, you can convert lambda to actual AFR by multiplying the lambda value by the fuel's stoich AFR. This is basically what your wideband gauge is doing!

Advantages of Lambda

  1. Consistency: Lambda provides a consistent scale across different fuel types, making it easier to compare and adjust mixtures.
  2. Simplicity: It's easier to calculate percentage changes from stoichiometric using lambda.
  3. Fuel flexibility: Lambda is particularly useful when working with varying ethanol blends.

While both AFR and lambda provide valuable information, many tuners prefer lambda for its simplicity and consistency when working with varying ethanol blends. Remember, normal gasoline is 0-10% Ethanol (AKA E0-E10) while E85 is 51-85% Ethanol, and you can run any mix of the two (E0-E85) with the eFlexPro kit installed.

See this Motortrend article for further reading on AFR Vs. Lambda: https://www.motortrend.com/how-to/1711-explained-the-difference-between-lambda-and-afr/

 

Still have questions? We are here to help!

  • First, try visiting the Customer Support Center at support.eflexfuel.com and searching and/or browsing our troubleshooting guides. Most answers are there!
  • Email us at support@eflexfuel.com 
  • Call us Mon-Fri between 9AM-5PM PT at 833-539-3835

 

Thank you for joining the #E85Movement!

 

We hope you make the most of your additional torque and horsepower. We invite you to follow us on Facebook (eFlexFuelUSA) and Instagram (@eflexfuel) to join a community of likeminded individuals. Most importantly, have fun and enjoy your drive!