GenBoard/VerThree/FlexFuel (2023-08-30 13:17:35)

Flex Fuel Sensor input :

See GenBoard/VerThree/FlexFuel/HardWare for hardware specific info

Summary: Using the GM/Continental sensor directly is possible using a digital input (wheelspeed1, wheelspeed2, or from a digital on 2nd serial with appropriate adapter if desired) wheelspeed2 most typically

Sensor outputs 50Hz at 0% Ethanol, 150Hz at 100% ethanol

VemsTune Setup:

Note: It is recommended to use 1.2.38 firmware. Several more anytrims were added in 1.3.32 which helps here.

To set up adjustments based on ethanol content (example):

Motorsports -> Anytrim Control

Anytrim 1 = Fuel Trim, Speed2 Input

Anytrim curve: Set the fuel adjustment curve. Roughly 0-30% from 50kph (0% Ethanol) to 150kph (100% Ethanol)

Use additional anytrims if you want to adjust boost target, etc.

With anytrim function


TODO: Flex fuel configlet to set multiple config options with 1 click (also: update VT help)

Speed sensor settings for flexfuel guide works:

In anytrim the road speed is always +50 to actual ethanol content so tuning is from 50kmh - 150kmh representing 0-100% Ethanol content.

It is common to add a new symbol in VemsTune. You can edit the firmware version's calc-model-common .ini file in C:\Program Files (x86)\VemsTune-2018-01-04\config\include

ex. calc-model-common-1.2.38.ini or if there isn't a calc-model-common for your firmware, edit C:\Program Files (x86)\VemsTune-2018-01-04\config\vemsTune-v3-<firmware>.ini

Add a stanza that is "ethanol = speed2-50" if you use wheelspeed2 for your ethanol sensor

Save and close the ini file. Start (or restart) VemsTune, and go to View -> Editors -> Add new symbol descriptor

Choose "All" for a filter, and look for ethanol or whatever you named it. Choose a symbol group that makes sense. We use Fuel/Enrichments in our setups. Set a title that you like Ethanol or Flex-Fuel is sensible. Click Create.

Then you can add or modify a gauge to display ethanol content. Right click an unused or un-needed gauge, "Change Gauge Data", Fuel/Enrichments, Ethanol

Hopefully we can soon get this integrated into VemsTune and re-released so it's built-in (as below)


Is it possible to develop V3 so that Speed Sensor settings allow to designate which speed input is Flex Fuel (which then automates these settings)

At the same time fuel temperature which is represented by duty cycle could also be implemented as fuel temp and also allowed in anytrim as fuel correction. Just two channels that would make a world of difference in user approach to flex fuel and working with varying fuel temp for proper fuel amount calibration.

This would allow anytrim fuel, ignition and boost control to be reflected by actual ethanol content channel.