Lund Flex Tune and learning question

Deca

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So I took receipt of the RTD and Lund flex tune, but only later Lund informed me that the flex tune needs to be 'learned' everytime I fuel the car. My impression was that since it is 'flex' I can just go ahead and fuel 93 and E85 however I please and the system will adapt based on ethanol%. However, now I understand that everytime I fuel up, I have to do 10 minutes of idle + neutral revs before driving. Is this right, any experiences? Why can't the car learn on the fly while driving?

thanks!

 

NGOT8R

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It can learn while driving. I never idle more than a couple of minutes before I begin driving. I do however, take it easy until the ethanol content is learned. Usually takes me 15-20 minutes of driving.
 

jvandy50

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when i used the nGauge it would light up green when ready to go WOT...you could still drive the car beforehand, but no WOT until completely learned. and it never took 10 minutes.
 
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Deca

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thanks - don't think it can have anything to do with the fact that they moved to RTD instead of nGauge? they're quite adamant: "It'll take a good 10 mins of idle and neutral rev holds for the fuel to start mixing and for the ethanol % to start learning properly. Do not drive it immediately. It may learn incorrectly since the other fuel may remain in the lines and it may lock too soon to the wrong ethanol %."

so not only idle, but also neutral revving...
 

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You expecting it'll automatically adjust to any % ethanol right away ? Factory flex fuel vehicles take some time, and that's with a ethanol sensor, which our mustangs do not have. Don't matter if it's a nGauge or RTD, procedure is the same.
 
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Deca

Deca

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Not right away- but expected it to learn it while driving, not me idling/revving at the gas station
 

WildHorse

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Not right away- but expected it to learn it while driving, not me idling/revving at the gas station
They want you to clear all the fuel out of the lines before you start driving. For Lund, they're just looking after their asses. Less chance of blowing it up if you just sit there till it learns haha.
 

honeybadger

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FWIW, when I was on the dyno and did a fuel change, we just ran the car for 5-10 mins at ~2k to clear the lines. The car just pulled a crap ton of fuel on the short term trims while we did that. Just don't hit WOT while doing it
 

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Another thing to note is, with a flex fuel tune, the ECU is able to compensate for varying grades of ethanol and/or pump gas, unlike the E85R tune. I stay on my flex tune 95% of the time because it does exactly what is says: provides flexibility. I don’t sit and idle when on my flex tune after fill ups, but I don’t hammer the car until it learns the ethanol content which is generally within 15-20 minutes of normal driving for me.
 
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Deca

Deca

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Thanks guys - this all makes much more sense now compared to lund’s ass cover comments. Noticed that AFR is quite significantly lower on E85 than on 93. However, machine gunning is also less in E85! Other than that...not sure I really feel an improvement lol
 

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to lund’s ass cover comments.
My ass covering comment is the SOLE reason why LUND tells you to do it like that. Don't believe me ? Ask them directly. Afterall, they are the ones who wrote the tune.
 

MaskedRacerX

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Thanks guys - this all makes much more sense now compared to lund’s ass cover comments. Noticed that AFR is quite significantly lower on E85 than on 93. However, machine gunning is also less in E85! Other than that...not sure I really feel an improvement lol
When I was running my Flex Tune ('19 GT), I'd just run the 93 down pretty low, fill up with E at the pump, pull over to the side, let it idle for a minute, then just drive away, really easy, <3k RPM, and watch the AFRs, you'd see them drop, 12, 11, then stabilize at mid-10s in about 4-5 minutes (call it, 8-9 miles). My E supply is at a Gate station ~10 miles away, so that pretty much gave me the cycling I needed.

I was using an X4 tuner, so relied on the AFRs, which is possibly a touch reckless, but it worked, er, I guess, I never quite got my E tune worked out, mid-to-upper RPMs it pulled like crazy, I just had some low RPM stumbling issues - went back to just a 93 tune (it's a good one though, also worked over the A10).

Like you, I wanted the flexibility when E wasn't available, and the Gate here it isn't pure E85, it's a Flex mix, so the pump indicates a range 55-75 IIRC.
 
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Deca

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My ass covering comment is the SOLE reason why LUND tells you to do it like that. Don't believe me ? Ask them directly. Afterall, they are the ones who wrote the tune.
Ofc I believe you - was going back and forth with their Calibrator before I came here, but didnt get a straight answer.
 
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Deca

Deca

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When I was running my Flex Tune ('19 GT), I'd just run the 93 down pretty low, fill up with E at the pump, pull over to the side, let it idle for a minute, then just drive away, really easy, <3k RPM, and watch the AFRs, you'd see them drop, 12, 11, then stabilize at mid-10s in about 4-5 minutes (call it, 8-9 miles). My E supply is at a Gate station ~10 miles away, so that pretty much gave me the cycling I needed.

I was using an X4 tuner, so relied on the AFRs, which is possibly a touch reckless, but it worked, er, I guess, I never quite got my E tune worked out, mid-to-upper RPMs it pulled like crazy, I just had some low RPM stumbling issues - went back to just a 93 tune (it's a good one though, also worked over the A10).

Like you, I wanted the flexibility when E wasn't available, and the Gate here it isn't pure E85, it's a Flex mix, so the pump indicates a range 55-75 IIRC.

Cool - kept it idling for the recommended 10mins + rev holding. Even after those 10 minutes AFR was still 13-14, after driving now 10-11 idd. I understand btw that HPT may be releasing a phone app to monitor using the RTD
 

 
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