Flex Fuel Tune for silverado 2017

[eisaalali]

Hello Guys,

As you know the Silverado 2017 has flex fuel sensor

So as you increase the % of ethanol the stoich is changing but should I change the MAF calibration everytime I increase the ethanol or no

Example :

The car is tuned on MAF only and now it has pump gas with 0% ethanol but all the Flex fuel calibration is active So if I add E30 or E20 it will change the stoich but should I change the MAF calibration.

Thanks,

[TriPinTaZ]

no, there is no need to change the MAF. That is what the flex fuel sensor is for. It knows the stoich changes with the ethanol content and it adjust fueling. The MAF doesn't measure the volume of fuel needed, it measures airflow and the ECU calculates the volume of fuel needed based on stoich ratio, ethanol percentage and some others. Changing ethanol content doesn't change your airflow.

[eisaalali]

Thank you so much

no, there is no need to change the MAF. That is what the flex fuel sensor is for. It knows the stoich changes with the ethanol content and it adjust fueling. The MAF doesn't measure the volume of fuel needed, it measures airflow and the ECU calculates the volume of fuel needed based on stoich ratio, ethanol percentage and some others. Changing ethanol content doesn't change your airflow.

[5FDP]

You'll just want to do other changes for flex fuel to optimize it.

Like different commanded air fuel ratios and timing for wide open throttle. I run a leaner mixture on higher ethanol content and a few degrees more timing.

12.5 to 12.6 on 89 octane and 12.9ish on E60+.

[kevin87turbot]

Actually, most of the 2017 Silverado's do not have a flex fuel sensor. Most of them are equipped with a virtual flex fuel sensor. It's a strategy that GM uses in order to save the cost of installed an actual sensor. Typically, the 2014 Silverado's have a real flex sensor. Some of the 15 models do as well. The only 17 model that I've seen with a real flex fuel sensor was a police vehicle. Here's how you can tell if yours has one. If you click on the Flex Fuel tab, it will show Sensor or Virtual.

flex fuel screen.jpg

[eisaalali]

Actually, most of the 2017 Silverado's do not have a flex fuel sensor. Most of them are equipped with a virtual flex fuel sensor. It's a strategy that GM uses in order to save the cost of installed an actual sensor. Typically, the 2014 Silverado's have a real flex sensor. Some of the 15 models do as well. The only 17 model that I've seen with a real flex fuel sensor was a police vehicle. Here's how you can tell if yours has one. If you click on the Flex Fuel tab, it will show Sensor or Virtual.

flex fuel screen.jpg

Thank you so much, I have checked my Truck and made sure that it has a real flex fuel sensor,

[eisaalali]

You'll just want to do other changes for flex fuel to optimize it.

Like different commanded air fuel ratios and timing for wide open throttle. I run a leaner mixture on higher ethanol content and a few degrees more timing.

12.5 to 12.6 on 89 octane and 12.9ish on E60+.

Yes with higher ethanol content you can run leaner

[Awaters54]

Does anyone have a Flex fuel tune they wouldn't mind sharing for a 2017 Silverado 5.3?