Confused about Flex Fuel Tune

[goldeneagle6747]

Okay I had thought I did enough research on my own and was ready to reach out to Lund for a flex fuel tune and got this response.

" We make tunes for both 93 and E85 but they are separate and not a flex tune, we stopped flex tuning because it caused nothing but issues as people were driving on it constantly instead of only using it for transition like it was meant. "

So I guess my question is, have recent developments shown the Flex Fuel actually isn't a safe tune? I was under the assumption that it was from all I read, and if it is, are there any reputable shops doing it?

If not, could I still switch between an e85 and 93 tune if needed without too many issues? There are a few e85 stations in my area but I don't know what they test at and I don't want to be left stranded if I need to take a road trip.

If not part 2, how much am I loosing out on with a 93 tune vs a e85 tune.

Car is completely stock but looking at getting catted LTHs in the nearish future.

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[NGOT8R]

Here’s a video that explains why Lund stopped writing Flex tunes.

 

[goldeneagle6747]

Here’s a video that explains why Lund stopped writing Flex tunes.

Thank you, I'll give it a watch after work. I tried searching this forum and reddit for an explanation and didn't find one in the limited searching I can do while nobody is in eyesite of my computer.

 

[K4fxd]

Most of that VId is a bunch of BS.

I see you have a gen 3 coyote, you need to find someone who tunes with PCMtec and understands Ford logic. Or wait till Lund offers PCMtec's can based flex option.

 

[NGOT8R]

I got my Flex tune from Lund just over 3 years ago and it works perfectly. I actually ran on it the majority of the time until last year when I put the car on the E85R tune permanently. I can say that my car did not run as smoothly on 93 with the Flex tune loaded, so I only ran 93 if I couldn’t fined E85.

 

[NGOT8R]

Thank you, I'll give it a watch after work. I tried searching this forum and reddit for an explanation and didn't find one in the limited searching I can do while nobody is in eyesite of my computer.

Basically the Flex was always intended as a transition only tune..

 

[goldeneagle6747]

What is the current day recommendation then? I have no issues using e85 99% of the time, my main concern was the gas stations e85 not always being a perfect e85. Is the easiest answer just a 93 tune if I don't want to have to test the gas every time?

 

[K4fxd]

Basically the Flex was always intended as a transition only tune..

From Lund I suppose it was.

 

[K4fxd]

What is the current day recommendation then?

Find someone who tunes with PCMtec and understands Ford's logic. I'm not sure but @engineermike might be in the tune business.

 

[K4fxd]

Here is one thread of many about flex

https://www.mustang6g.com/forums/threads/true-flex-fuel-tune.190160/

 

[SheepDog]

Okay I had thought I did enough research on my own and was ready to reach out to Lund for a flex fuel tune and got this response.

" We make tunes for both 93 and E85 but they are separate and not a flex tune, we stopped flex tuning because it caused nothing but issues as people were driving on it constantly instead of only using it for transition like it was meant. "

So I guess my question is, have recent developments shown the Flex Fuel actually isn't a safe tune? I was under the assumption that it was from all I read, and if it is, are there any reputable shops doing it?

If not, could I still switch between an e85 and 93 tune if needed without too many issues? There are a few e85 stations in my area but I don't know what they test at and I don't want to be left stranded if I need to take a road trip.

If not part 2, how much am I loosing out on with a 93 tune vs a e85 tune.

Car is completely stock but looking at getting catted LTHs in the nearish future.

You get both a 93 and E85 tune, when you purchase the E85 Tune because the tuner will first want to dial in the gasoline calibration, before switching you to E85. You are never "stranded" when running the E85 tune. If you are almost out of fuel, and only gasoline is available, then flash your 91/93 tune and put some gasoline in it. Once you are down to a gallon or so, fill er' up with E85 and flash back to the E85 calibration. Most stations get either E70ish, or E85. Both of which are fine on an E85 calibration. Some stations like in Arizona get E54 which would require a slight change to the tune. Get yourself a test kit, or better yet, get the Fuel-It ethanol sensor kit and never guess again.

E85 (or E70 for that matter) over 93 is a dramatic improvement in power.

 

[goldeneagle6747]

You get both a 93 and E85 tune, when you purchase the E85 Tune because the tuner will first want to dial in the gasoline calibration, before switching you to E85. You are never "stranded" when running the E85 tune. If you are almost out of fuel, and only gasoline is available, then flash your 91/93 tune and put some gasoline in it. Once you are down to a gallon or so, fill er' up with E85 and flash back to the E85 calibration. Most stations get either E70ish, or E85. Both of which are fine on an E85 calibration. Some stations like in Arizona get E54 which would require a slight change to the tune. Get yourself a test kit, or better yet, get the Fuel-It ethanol sensor kit and never guess again.

E85 (or E70 for that matter) over 93 is a dramatic improvement in power.

This the one you are talking about? I have never seen this mentioned but I will look into it.

https://fuel-it.com/products/fuel-it-flex-fuel-kits-ford-mustang-5-0?variant=40077183484043

 

[SheepDog]

This the one you are talking about? I have never seen this mentioned but I will look into it.

https://fuel-it.com/products/fuel-it-flex-fuel-kits-ford-mustang-5-0?variant=40077183484043

Correct. Sends the data to an app on your phone. No more fuddling around with a test tube, bottle of water, spilling fuel on yourself etc.

 

[Dapepper9]

OzTuning, OrtizPerformance and others still flex tune. Oz has it down pat and I wouldn't hesitate to do it.

 

[mejohn50]

The Ford OEM flex logic can be made to work just fine. There are two caveats though:

1) you have to find someone who does it right and adjusts ALL the parameters.

2) you have to understand the limitations of the system. Ford even says in their own bulletins that their flex logic isn’t for filling up with whatever fuel back and forth without a care in the world. It’s more for using one type of fuel primarily, and when you don’t or can’t use that fuel, you can safely fill up with the other type of fuel while understanding there’s a transition period that you need to be aware of.

The PCMTEC sensor-based flex fuel is another option. I think there’s only a handful of US cars running it right now, but I wouldn’t be surprised to see kits and tunes soon. The PCMTEC implementation also has a lot more room to make it work how the tuner wants. Nearly any table in the tune can be blended based on ethanol content.

I have played with the Ford flex logic on a boosted Coyote that was already on the ragged edge on pump gas with zero issues. But, once I saw PCMTEC’s sensor-based flex fuel I pretty much stopped testing the Ford logic and waited until I could add the sensor to my setup. I am just waiting for a custom designed bracket to mount the ethanol sensor under the hood and I’ll be good to go.

If it were me and my money, I’d wait to see the PCMTEC flex fuel roll out and go from there.

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