E85 help needed

I have a 2020 F150 3.5 ecoboost. I?m trying to run E85 due to the high fuel prices and ease of its availability near me. Not looking for a race tune or anything. Just the ability to run it. I see a partially filled out flex fuel option but I?m not sure how to proceed with filling in the blanks as I can?t find any reference material for a flex fuel enabled vehicle. Also has anyone been successful with this? The learning curve here is steep but I?m trying to be safe about it.

Is it possible to just change the stoich and run it?

Thanks for any help.

You can just change the stoic if you are always going to run a consistent mix but you will run out of fuel when you reach around E35/E40 based on your tune. You will use approx 30% more fuel than standard gasoline. There is a great video on YouTube by Goat Rope Garage showing adjusting the parameters of you want to convert to the flex fuel tune. I’m a few steps ahead of you in the conversion process. Also, just going to the E35 gave me about a 50 ft lb torque increase without any other tuning changes except flex fuel enabling.

Ok sounds good. I did find some info on a thread you were previously on as well. So I made a few changes to my file to attempt a "flex fuel" tune. Looks like I need to upgrade the HP Pump in order to run E85 so I'll stick with E30 for testing / tuning etc.. If you have a chance could you look at my tune file to see if anything stands out? If not I understand but since you've been where I am right now I figured you might see things I currently don't.

I?ll check it out when I get some time tomorrow and let you know if anything stands out. I?m still new to quite a few things but can probably point out the obvious. Also, you can either upgrade the high pressure or just the low pressure if you want to use E85. High pressure will offer more direct injection but still may require a booster pump or larger injectors based on the tuning. If you get a larger lift pump and port injectors (less than half the cost), you can run the stock high pressure setup and the remaining required fuel will be through the port injectors. Direct injection is better performance wise, but most say that above E40, you are maxing the effects regardless of injector style used.

Everything looks very close to my file. A few variables are .01-.001 difference but nothing that would cause issues or may even be better than what I have. The only thing I noticed you have to adjust is your (Fuel/Oxygen Sensor/Sensor bias/) settings. There are 4 tables for flex fuel settings. These tables adjust your 4 sensors (02's and cat 02's) voltages based on how they register AFR. They are already defined for regular fuel but are not for flex fuel. Some people copy the tables from the regular fuel over. I personally took the variations from a 5.0 flex fuel f-150 and adjusted my settings based on the differences they had between the regular gas to flex fuel. These changes are something probably not going to make a difference since most are like .001-.008 changes. The only thing to be careful of is your fuel rail pressures and lift pump pressures. At E35-E40, I'm running my pressures pretty lean at WOT. My desired high pressure rail is 2,000 PSI and I'm around 850-900 PSI. I'm about to install a larger lift pump (as soon as I use up this full tank of fuel I have now) and see how everything tracks.

Thank you!

I will update my file. I dont have access to a 5.0 flex table so I'll just copy over what I have.

I?ve got it running on E30 pretty well. The only thing I?m noticing is low speed higher load acceleration. Like light acceleration the truck feels a little like it?s struggling to go. If I use more accelerator it?s fine. The fuel pressures are good. Nothing in logs is standing out as an issue. Wondering if anyone has any ideas? Should I charge driver demand in the pedal settings or something? At WOT it runs out just fine. It?s just a part throttle butt dyno feeling I suppose. It?s just different.

I haven’t noticed anything like described. In theory, it should only require more fuel vs air with the characteristics. Any chance before you were having more knock with regular gas limiting power at higher loads but now you don’t have any so it just has more power top end (making it feel like less low-mid)?

that?s a possibility. I usually run 93 all the time but the fill up before making it run e30 was just 87. So that introduced some changes it how it drove. So when I started doing e30 I mixed e85 with what was in the tank then topped off with 88 octane e15 so it?s possible my calculations were off. Since then I?ve been filling up with e30 from the pump and also leaned out my stoich a little bit. Like .14. It?s been running pretty good since the last fill up. Getting about 19 to 20 mpg as well.

I ended up making a dedicated e30 tune. Works way better than trying to use the flex fuel tables.

Here is a E85 tune for you but the timing has not be turned up yet Under mapped 0 to 14. My truck only uses 0-7. I send you the charts and graft you to data log with. I also disabled popcorn for you and disabled skip shift and some other limiters you missed.
I am still working on the timing for my 87 octane and then I will work on my E85 timing next. Do not copy the MBT mapped settings are to high. I have ran this tune for a little while and its strong.Attachment 134276 I have the channels and grafts made out but can not post here. I would need an email address to send them to you. Mine is [email protected]