Flex fuel tunes

[3rdgenyote]

So I’ve heard flex fuel tunes are bad but I haven’t been told why I’m trying to figure wether I should bother with a flex tune or just go full e85 and just buy the drums of it… also has anyone heard of or been tuned by p1 tuners?

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[shogun32]

Just buy an E85 tune if you have a good, local source. Otherwise wait another 3 months while some smart cookies on this forum fully unravel the brain-dead ethanol detection Ford ships in the Mustang, so it works properly. Go do a search. You'll find plenty on the topic.

 

[HKusp]

Read this, you'll know more than you do now.

More than you probably want to.

 

[WildHorse]

Just buy an E85 tune if you have a good, local source. Otherwise wait another 3 months while some smart cookies on this forum fully unravel the brain-dead ethanol detection Ford ships in the Mustang, so it works properly. Go do a search. You'll find plenty on the topic.

I'm still convinced you'll need a ethanol sensor. That would be the safest/easiest way.

 

[3rdgenyote]

Makes sense

 

[ChitownStang]

0 issues with my Livernois Flex Tune. Fill it up with either 93 or E85 and drive normal for 10-15 min .
Runs great and strong.
problem and danger with E85 tune is that if it's not good e85 that you are tuned for or you can't find it you are in far worse shape. Flexibility is really nice and there is no downside other than maybe a few HP from a straight e85 tune.
My 2cents

 

[engineermike]

I've been playing with Flex tuning for the past few months. As of now, my conclusion is as follows:

- It can be super easy and safe. You can copy over all of the F150 flex/FFV/FF/alcohol/PM/methanol/etc parameters into the Mustang tune except for the borderline knock ethanol adder. Let the knock advance do what it does and you will very safely reap most of the benefits of E85. The downside to this is that you have to "wait" for the knock advance to get all of the extra timing in every time you go WOT.

- If you want better torque response, you can add 5-10 deg to that borderline FFV modifier table and the response will be better. Should you choose to do this, I would highly recommend reading the 2016 GSB from Ford and just heeding the last 3 bullet points. Flex Fuel Job Aid ─ 2003 and Newer (oemdtc.com) Also, if set up this way, an extra layer of protection is to simply watch the A/F ratio gauge when switching fuels. If it's running above 13/1, then you know that it's removed the additional flex timing.

- There's one catch....earlier I said copy "all" of the F150 parameters into the mustang tune. The problem here is that most tuners use HPTuners software to modify the files. HPTuners did not define the fuel volume in the fuel lines and pumps, so the risk is that the car locks into the wrong fuel before it has a chance to "see" it at the engine. Then, you could be applying too much timing if switching from E85 to gas. PCMTec does define these parameters. This is a must-do if doing flex tuning. @ChitownStang I believe Livernois does not use HPT for tuning so it wouldn't surprise me if they had this parameter corrected.

 

[ChitownStang]

I've been playing with Flex tuning for the past few months. As of now, my conclusion is as follows:

- It can be super easy and safe. You can copy over all of the F150 flex/FFV/FF/alcohol/PM/methanol/etc parameters into the Mustang tune except for the borderline knock ethanol adder. Let the knock advance do what it does and you will very safely reap most of the benefits of E85. The downside to this is that you have to "wait" for the knock advance to get all of the extra timing in every time you go WOT.

- If you want better torque response, you can add 5-10 deg to that borderline FFV modifier table and the response will be better. Should you choose to do this, I would highly recommend reading the 2016 GSB from Ford and just heeding the last 3 bullet points. Flex Fuel Job Aid ─ 2003 and Newer (oemdtc.com) Also, if set up this way, an extra layer of protection is to simply watch the A/F ratio gauge when switching fuels. If it's running above 13/1, then you know that it's removed the additional flex timing.

- There's one catch....earlier I said copy "all" of the F150 parameters into the mustang tune. The problem here is that most tuners use HPTuners software to modify the files. HPTuners did not define the fuel volume in the fuel lines and pumps, so the risk is that the car locks into the wrong fuel before it has a chance to "see" it at the engine. Then, you could be applying too much timing if switching from E85 to gas. PCMTec does define these parameters. This is a must-do if doing flex tuning. @ChitownStang I believe Livernois does not use HPT for tuning so it wouldn't surprise me if they had this parameter corrected.

This is great info Mike, thank you.
It’s funny how some of these tuners you ask say they don’t recommend to drive on the Flex tune then they will say, I do it and it works fine. That was Wengard that said that.
Lund won’t do Flex anymore.
And PBD said it was fine to run always on the Flex.
So many different answers really confuse people.
I was really thinking of Wengard for the A10 tunreal people seem to love but that answer on the Flex has scared me away.

 

[engineermike]

Iirc wengard uses hptuners.

 

[junits15]

This is great info Mike, thank you.
It’s funny how some of these tuners you ask say they don’t recommend to drive on the Flex tune then they will say, I do it and it works fine. That was Wengard that said that.
Lund won’t do Flex anymore.
And PBD said it was fine to run always on the Flex.
So many different answers really confuse people.
I was really thinking of Wengard for the A10 tunreal people seem to love but that answer on the Flex has scared me away.

The worst part is that they could make this work. These guys are big and have push with HPT, but the current functionality of flex through HPT is "good enough" to make money on so they just let it ride as is.

Its not for lack of hardware, its lack of software. Which is just unfortunate.


Also PCMtech has true flex in the works with a sensor, which would be a good solution if mike and the others involved can't get the inferred flex to work as we need it.

 

[nnnnnn]

Isn't it better to get a good E-85 tune then install a pro flex commander to do the flex tuning for you and save yourself the headache? Just a suggestion

 

[engineermike]

Isn't it better to get a good E-85 tune then install a pro flex commander to do the flex tuning for you and save yourself the headache?

No.

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