N/A flex tune understanding

[sdskinner73]

I have my car tuned by Wengerd. I ran the 93 tune, then e85 for most of summer. Now that temperatures will start dropping as well as E85 quality, I swapped to a flex tune. He told me if I was going to use just 93 for winter, use the 93 tune instead. I was under the impression a flex tune is so you can use either/or, but seems I was misinformed. I live in Indiana, so E95 in our winter is not ideal for starting the car. I don’t want to blowup his emails. Can someone explain the correct way to use a flex tune?

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[robvas]

Just do what he says and flash back to the 93 tune until spring.

 

[EFI]

The flex tune can adjust for E10 93 gasoline, but it takes a while to learn the new fuel and trims. A 93 tune will be obviously quicker to adjust, but in the end both will do the same.

If you have the option for a pure 93 tune, just go with that as the tuner recommended.

 

[sdskinner73]

Just do what he says and flash back to the 93 tune until spring.

I will over the next couple weeks. But to do that, do I use 93 on the next full tank, and in the second fill up swap tunes? I asked for the flex tune so I don’t have to drop my tank so low to swap.

 

[robvas]

I will over the next couple weeks. But to do that, do I use 93 on the next full tank, and in the second fill up swap tunes? I asked for the flex tune so I don’t have to drop my tank so low to swap.

Fill up on 93 when you get to a quarter tank and load your 93 tune and be done with it.

 

[sdskinner73]

Fill up on 93 when you get to a quarter tank and load your 93 tune and be done with it.

Perfect. Never tuned on anything besides 93 before now, so trying to be safe. Thanks!

 

[engineermike]

If a flex tune can’t:

• Fully adapt to a fuel switch in 10 minutes.
• Avoid locking into a new fuel prematurely.
• Float spark timing as a function of ethanol %.
• Cold start easily even at cold temps.

…then it’s not really a flex tune.

 

[sdskinner73]

If a flex tune can’t:

• Fully adapt to a fuel switch in 10 minutes.
• Avoid locking into a new fuel prematurely.
• Float spark timing as a function of ethanol %.
• Cold start easily even at cold temps.

…then it’s not really a flex tune.

He did not say it can’t do those things. But recommended to use the dedicated tune if sticking with that specific fuel. I’m not risking e85 sitting when it gets cold. In the garage it’s not an issue, but leaving work at negative temperatures could be. Not really worth the risk to me.

 

[junits15]

He did not say it can’t do those things. But recommended to use the dedicated tune if sticking with that specific fuel. I’m not risking e85 sitting when it gets cold. In the garage it’s not an issue, but leaving work at negative temperatures could be. Not really worth the risk to me.

What are you worried about happening when the e85 gets cold? I've run it year round without issues.

 

[robvas]

What are you worried about happening when the e85 gets cold? I've run it year round without issues.

Depends on what "cold" means

 

[junits15]

Depends on what "cold" means

I’ve run it in the teens, which means it spent the night below zero. It won’t freeze if that’s the concern.

 

[sdskinner73]

I’ve run it in the teens, which means it spent the night below zero. It won’t freeze if that’s the concern.

That is exactly my concern. I’ve read conflicting things about it. I live in central Indiana, so depending on the day, I could see negatives in the winter.
But at the very least, it wouldn’t hurt to drop some HP for the winter anyways

 

[junits15]

That is exactly my concern. I’ve read conflicting things about it. I live in central Indiana, so depending on the day, I could see negatives in the winter.
But at the very least, it wouldn’t hurt to drop some HP for the winter anyways

The freezing point of ethanol is -174F, colder than gasoline. it will not freeze in your tank.

But I get what you're saying you can't really beat the car up in the winter anyway.

 

[robvas]

I’ve run it in the teens, which means it spent the night below zero. It won’t freeze if that’s the concern.

Of course it won't freeze, but hard starting etc.

 

[junits15]

Of course it won't freeze, but hard starting etc.

Yeah that can happen, but properly done tunes won’t. I think most of the big names here have decent cold start behavior on e85.

mines copied from the f150 it’s amazing how well it works. It’s getting cold now, I should get a video. I had a lot of help from some very smart people to get the cold start flawless.

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