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Flex tune for E85 and gas

covidcommander

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#1
Wondering how this type of works? They use the a/f ratio to know the e85 content and make the changes?
 


moparjim

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#2
They use inferred logic from info given by the o2 sensors. Same way GM and Dodge have their flex fuel setups. Ford uses a sensor. I may have mixed up Ford and GM but you get the idea.🤔
Arguably this method is slower to react to changes.
 


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#3
E85 is just a regular tune with changes made for the fuel used. Flex is completely different. Not sure which you're asking about.
 


moparjim

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#4
E85 is just a regular tune with changes made for the fuel used. Flex is completely different. Not sure which you're asking about.
Correct there I go assuming again.🤦
 


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#5
LOL, the question was worded a bit funny so I'll give ya this one :LOL:
 


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#6
To make this post even more fun these cars aren’t even tuned in AFR 😂 isn’t dodge fun😊

if a straight e85 tune is wanted. There are many changes to be made to get the afr gauge in your car to display correctly. A lot of tuners don’t do that and just adjust injector data to make the e85 work.
As said flex is a whole different game.
 


OP
covidcommander

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Thread Starter #7
E85 is just a regular tune with changes made for the fuel used. Flex is completely different. Not sure which you're asking about.
Flex tune... sorry
 


OP
covidcommander

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Thread Starter #8
LOL, the question was worded a bit funny so I'll give ya this one :LOL:
Yeah my brain works funny sometimes 🤷‍♂️
 


OP
covidcommander

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Thread Starter #9
To make this post even more fun these cars aren’t even tuned in AFR 😂 isn’t dodge fun😊

if a straight e85 tune is wanted. There are many changes to be made to get the afr gauge in your car to display correctly. A lot of tuners don’t do that and just adjust injector data to make the e85 work.
As said flex is a whole different game.
Yeah it would be how the flex tune works...

I was watching a video and they were talking about the neural network being disabled when using a flex tune. Just trying to understand how it works after watching a whole bunch of videos on hp tuners
 


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#10
Yeah it would be how the flex tune works...

I was watching a video and they were talking about the neural network being disabled when using a flex tune. Just trying to understand how it works after watching a whole bunch of videos on hp tuners
There are very limited videos on hemi tuning. Everyone is pretty hush hush about it. But whatever you saw about flex fuel not using NN is false. I bet 99.9 percent of all flex cars still have NN enabled.
 


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covidcommander

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Thread Starter #11
There are very limited videos on hemi tuning. Everyone is pretty hush hush about it. But whatever you saw about flex fuel not using NN is false. I bet 99.9 percent of all flex cars still have NN enabled.
Yeah idk sometimes. I'm confused enough without false information
 


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#12
Yeah idk sometimes. I'm confused enough without false information
If you are looking to try and tune yourself. Start with 93. No added boost. Get a feel for things. Then add injectors. Tune those in and then go from there. You could also play around with your stock injectors a bit if you were looking to practice.
There are a few of us on here that take on this challenge. But this just isn't something you are going to figure out in 5 or 10 hours. You are going to have numerous hours into trial and error depending on how crazy you plan on going.
 


OP
covidcommander

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Thread Starter #13
If you are looking to try and tune yourself. Start with 93. No added boost. Get a feel for things. Then add injectors. Tune those in and then go from there. You could also play around with your stock injectors a bit if you were looking to practice.
There are a few of us on here that take on this challenge. But this just isn't something you are going to figure out in 5 or 10 hours. You are going to have numerous hours into trial and error depending on how crazy you plan on going.
No just wondering what they do. I wouldn't tune my own car. That's above my pay grade. I could swap injectors pullies etc. I leave the tuning to the professionals
 


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#14
No just wondering what they do. I wouldn't tune my own car. That's above my pay grade. I could swap injectors pullies etc. I leave the tuning to the professionals
Keep in mind different tuners do some things differently, so there is not necessarily only one correct way of doing things. I personally am not a fan of inferred flex tunes, so we do not do them for customers. I realize tuning information is "hush hush" with the hemis, but the just of it involve installing a software patch then there are a lot of changes within the flex fuel tables that have to be modified.

Ive done it onvmy personal car, but now just run a dedicated e70 tune, and swap pulley and tune for trips so I can run 93
 


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#15
Keep in mind different tuners do some things differently, so there is not necessarily only one correct way of doing things. I personally am not a fan of inferred flex tunes, so we do not do them for customers. I realize tuning information is "hush hush" with the hemis, but the just of it involve installing a software patch then there are a lot of changes within the flex fuel tables that have to be modified.

Ive done it onvmy personal car, but now just run a dedicated e70 tune, and swap pulley and tune for trips so I can run 93
I like flex option for daily driving reasons.I'd never want to push one to the limits as far as timing goes. I see a lot of tuners posting dyno numbers and saying only fuel change no tune or boost change. That can be dangerous. Also depending on the tune the learning takes time so if I have e85 in and run it low and fill it right up with 93 and go floor it right away. There is going to be a whole lot of timing coming my way way and if to aggressive the knock sensors wont stand a chance. Also hp tuners isn't 100% there yet. My car has a glitch with the flex patch where the fans will never shut off. They've been working on that for awhile now. If I sent my PCM in and had it flashed to another OS I wouldn't have the issue.
 


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#16
Flex is great, but as a consumer you have to educate yourself on some of the nuances. Giving time for the car to figure out what's in it on fuel changes and monitoring that "somehow". I use the the AFR gauge personally since it'll show what the car thinks is in the tank and I'll know when it's figured it out. Mine usually does it within 5 minute or so, so like Jon says don't just pull out of the gas station and go WOT. Mine's a 2016 model so the FF stuff didn't give me too many problems, but different OS react differently as Jon also points out, so keep that in mind. Some just flat won't work from what I hear as well, so changing OS versions is the solution there. Not a huge deal at all though, just need someone who can do it. OEMs change OS versions on in the field vehicles at times so don't be worried about that.

Going back and forth 5 gallons at a time also isn't recommended. Run one fuel most of the time, and when you wanna change from say E85 to 93 then run the car to almost empty and fillup with the new fuel you plan to run.

Reviewing Flex Fuel information from the owner's manual of an OEM Flex Fuel vehicle will pretty much say these same things.
 


BULL

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#17
Flex is great, but as a consumer you have to educate yourself on some of the nuances. Giving time for the car to figure out what's in it on fuel changes and monitoring that "somehow". I use the the AFR gauge personally since it'll show what the car thinks is in the tank and I'll know when it's figured it out. Mine usually does it within 5 minute or so, so like Jon says don't just pull out of the gas station and go WOT. Mine's a 2016 model so the FF stuff didn't give me too many problems, but different OS react differently as Jon also points out, so keep that in mind. Some just flat won't work from what I hear as well, so changing OS versions is the solution there. Not a huge deal at all though, just need someone who can do it. OEMs change OS versions on in the field vehicles at times so don't be worried about that.

Going back and forth 5 gallons at a time also isn't recommended. Run one fuel most of the time, and when you wanna change from say E85 to 93 then run the car to almost empty and fillup with the new fuel you plan to run.

Reviewing Flex Fuel information from the owner's manual of an OEM Flex Fuel vehicle will pretty much say these same things.



It would seem that changing "up" to a tank of E85 wouldn't be a problem, right???

But going "down" to 91/93 would be a problem if the car has "adjusted" itself to the E85.


Well from a spark standpoint anyway, I guess injectors would be jacked....

Nevermind...
 


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#18
Exactly, it's best to let it figure everything out before you started giving it too much loud pedal.
 


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#19
Here are a few pictures of a non flex tune so no values are entered. But maybe this will help give an idea of just a tiny part of what is required to make the flex work.
1648669579241.png
1648669772308.png
 




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