True Flex Fuel Tune

[engineermike]

@vaeevictiss your concern is justified and exactly why we are focusing on this. So far, my favorite fail safe is only toggling the borderline timing adder when inferred alcohol is over 55%. This will toggle it off pretty quick when switching to 93. Secondly, this allows me to watch the A/F gauge in the car. 55% alcohol is 11.5/1 inferred A/F, so I know when it hits 12/1 at steady state, it's using the "low" timing values.

@junits15 I get what you're saying about the knock adder but man I hate the power delay when waiting for 10 deg knock advance to come in. I have mine set up to only need to deg knock advance and I cap it at 2 as well. That said, I tried getting octane adjust to work because that would have been much easier than building the humidity-timing device. However, I tried everything I could find and I couldn't get octane correction to budge off of 0. Others have had similar experience with the Gen3 and finally just concluded that the logic isn't active in the OS. That said, it's possible PCMTech has what's needed to make it work but I haven't gone down that rabbit hole yet.

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[junits15]

@junits15 I get what you're saying about the knock adder but man I hate the power delay when waiting for 10 deg knock advance to come in. I have mine set up to only need to deg knock advance and I cap it at 2 as well. That said, I tried getting octane adjust to work because that would have been much easier than building the humidity-timing device. However, I tried everything I could find and I couldn't get octane correction to budge off of 0. Others have had similar experience with the Gen3 and finally just concluded that the logic isn't active in the OS. That said, it's possible PCMTech has what's needed to make it work but I haven't gone down that rabbit hole yet.

I actually was trying to say the reverse of that, if sh*t hits the fan, the car can remove 10* of timing, so as long as we don't increase borderline and MBT by more than 10 degrees, it should be able to pull out all of our additional timing and bring us back to "stock".

That is unfortunate, I didn't know it was so complicated to get that working, I honestly assumed it was just a few switches and tables. I should have know better by now lol. I used to have an 87-93 tune for my ST that worked with octane adjust. It was pretty nifty but suffered from being slow to learn which caused me to ditch it. That was before I knew how to do any of this so I was reliant on a tuner. Another thing to look into I guess! Anyway enough derailing about OAR.

I'm very excited to try this ethanol tweak once my dongle comes in!

 

[K4fxd]

That Brazil switch has me intrigued.

 

[engineermike]

@junits15 i have mine set up to be about 3 deg shy of knock before knock adder then it adds 2. When ethanol is over 55% it adds 7 deg. So theoretically it will be about 4 deg past knock right on the hit if erroneously using e85 timing on 93. This seems quite deep into knock for the initial hit and probably dangerous.

I supposed I could take 4 deg out of the borderline tables and the initial hit would be right at knock if it erroneously applies e85 timing to 93, but then I’d have to wait on about 6 deg of knock advance before I get all the power when on 93.

 

[junits15]

@junits15 i have mine set up to be about 3 deg shy of knock before knock adder then it adds 2. When ethanol is over 55% it adds 7 deg. So theoretically it will be about 4 deg past knock right on the hit if erroneously using e85 timing on 93. This seems quite deep into knock for the initial hit and probably dangerous.

I supposed I could take 4 deg out of the borderline tables and the initial hit would be right at knock if it erroneously applies e85 timing to 93, but then I’d have to wait on about 6 deg of knock advance before I get all the power when on 93.

Hmmm that is a lot to ask of the KR system. I guess you're right then, we can't rely on KR to protect us in a bad situation.

its better than nothing, but probably not enough to really rely on.

 

[junits15]

@junits15 i have mine set up to be about 3 deg shy of knock before knock adder then it adds 2. When ethanol is over 55% it adds 7 deg. So theoretically it will be about 4 deg past knock right on the hit if erroneously using e85 timing on 93. This seems quite deep into knock for the initial hit and probably dangerous.

I supposed I could take 4 deg out of the borderline tables and the initial hit would be right at knock if it erroneously applies e85 timing to 93, but then I’d have to wait on about 6 deg of knock advance before I get all the power when on 93.

Just out of curiosity, how do you add your timing? Are you blanket adding it across all the tables? Or are you tuning individual cam angle pairs?

 

[engineermike]

Just out of curiosity, how do you add your timing? Are you blanket adding it across all the tables? Or are you tuning individual cam angle pairs?

You talking about knock adder, ethanol adder, or borderline adder?

 

[junits15]

You talking about knock adder, ethanol adder, or borderline adder?

Oh wow I was completely confused, I forgot we're using the ethanol adder table for this.

The question was about borderline/mbt and adding to the mapped points, but that's not relevant to ethanol because we have the adder table.

 

[K4fxd]

Can anyone find the ethanol adder table in a gen 2. I'm striking out. It has the blend table but no adder that I can find.

Thanks

 

[K4fxd]

Could I use the octane adjustment table and use it as an adder instead of subtracting?

 

[Grimreaper]

Its not in the gen2 that I've ever found. Hptuner had a post years back that there wasn't one during bin compiling as well.

Pcmtech read my roush file but isn't defined yet. Sent to their support to see what they can do. Would love access to traction control..

Given the variables that can change stft/ltft, flex should be a bit softer than e85 tunes. There are guys on here that have lost motors na running 93 on flex tunes. Personally I use it for fuel changes only and leave timing set at highest 93 will allow.

 

[engineermike]

Could I use the octane adjustment table and use it as an adder instead of subtracting?

I think it will work, sort of. Learning lower timing could be painful.

 

[WildHorse]

injector data and spent time to fine tune my maf curve.

Doesn't Ford Flex learn alcohol content by watching fuel trim, MAF readings, and injector pulse width ?

 

[engineermike]

Doesn't Ford Flex learn alcohol content by watching fuel trim, MAF readings, and injector pulse width ?

I believe the learning *rate* is purely a function of average fuel trim and some pid feedback loop driving the fuel trim to 0. However, if the fuel trims aren’t near zero base-case, then the learning is doomed to be inaccurate. Garbage in gabage out. Therefore, in order for the learning to work right, the injector data and maf curve need to be accurate in order for base-case fuel trims to be low.

 

[K4fxd]

This does look like the solution for FI flex tunes.

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