This possible while using E85?

[NGOT8R]

Mines more of a daily driver so I feel like the dedicated e85 tune would be annoying for me.

I was debating between a 93 tune and a flex tune for the moment to add a little horsepower. I was just curious what everyone is getting from these types of tunes, performance wise.

I hear you. That’s why I run on my Flex 95% of the time. I was just suggesting getting the E85R tune at the same time, because it should t cost you anything extra. Only use it when you want to go max effort.

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[Zrussian13]

I ran the car down to zero miles left then filled it up with 85. Started the car up and let it idle for 10-15min. Then drove it around for 30min no more then 50% throttle.
Getting an Innovate Motorsport dual gauge ethanol kit installed in a week so I’ll least know what % the 85 is.

Your flex tune should always be faster than the pump gas tune unless your putting ethanol free gas in. Even running e30 timing is better than 91/93. Down low you won't feel much difference unless your on a dedicated E tune but up top you will. Or at least you should if your tunes right. Are you running an aftermarket Intake? I know the turbulence on some can effect the maf reading and make the ethanol learning logic struggle but it's still workable if you do it right.

Also I wouldn't install an ethanol sensor on a returnless system. You'll probably be ok but I wouldn't want a restriction on the feed side of my fuel system.

 

[Fusion Training Systems]

Your flex tune should always be faster than the pump gas tune unless your putting ethanol free gas in. Even running e30 timing is better than 91/93. Down low you won't feel much difference unless your on a dedicated E tune but up top you will. Or at least you should if your tunes right. Are you running an aftermarket Intake? I know the turbulence on some can effect the maf reading and make the ethanol learning logic struggle but it's still workable if you do it right.

Also I wouldn't install an ethanol sensor on a returnless system. You'll probably be ok but I wouldn't want a restriction on the feed side of my fuel system.

I have a JLT, 1050 injectors, kooks LT, cat back exhaust and larger TB.
Note taken on the gauge. I just thought it help reading the fuel so I know exact % of fuel.
It goes back in the shop next week for the tuner to check everything out and make adjustments as needed.
Thank you.

 

[Zrussian13]

I have a JLT, 1050 injectors, kooks LT, cat back exhaust and larger TB.
Note taken on the gauge. I just thought it help reading the fuel so I know exact % of fuel.
It goes back in the shop next week for the tuner to check everything out and make adjustments as needed.
Thank you.

I had a jlt when I was NA too and sometimes it struggled to adjust right on the flex tune. If I wasn't getting gas from a station I knew well, I'd test the fuel. Then I'd calculate exactly what my e% should be so I could make sure my afr adjusted right. At first it would settle in way off so I'd have to do a quick kam reset and let it relearn. I had to adjust my learning procedure to get it adjusting better on the first try.

 

[NGOT8R]

Something else to consider when tuning is, if you think you will want to lock out your IMRC system, do it before the tune, or it will cost extra down the road to turn them off in the tune. I installed an MMR IMRC lockout kit on mine and had to pay an additional $150 to turn them off in all four of my existing tunes.

 

[ChitownStang]

I used a local tuner who has a great reputation with mustangs. He had it on the dyno and road along with me while data logging everything.
He himself owns the same year mustang as mine on a flex tune and never has issues.
Could it be also maybe the fuel I’m getting is lower than 85?

My only station that has E85 near me tests consistently at E70 and my Flex runs fine on it.
Do custom tuners have the same tools as bigger tuners online I wonder.
People like Lund won’t do Flex but PBD and Livernois do it no problem.
My local tuner says he will only do dedicated 93 or E85 tune no flex.
So many different stories when I was doing all my research

 

[Prodigal]

Isn’t a flex tune sort of a decent across the board but great nowhere type tune?
I have easy access to 100% 91 octane and E85. I would only use the flex as a transition from one to the other but would expect it to perform lesser than either the 91 pure gas or the E85.

 

[NGOT8R]

When did Lund stop doing Flex tunes? They did one for me in 2020 and my car lives on that tune. Very rarely do I switch over to my dedicated E85 or 93 tunes.

 

[GregO]

I have a JLT, 1050 injectors, kooks LT, cat back exhaust and larger TB.

I’m going out on a limb here and singling out the 87mm throttle body tables, 93 vs. Flex.
Just a WAG but figured I’d throw it out there and let that idea get kicked around a bit.

 

[Zrussian13]

Isn’t a flex tune sort of a decent across the board but great nowhere type tune?
I have easy access to 100% 91 octane and E85. I would only use the flex as a transition from one to the other but would expect it to perform lesser than either the 91 pure gas or the E85.

If your running e85 on a flex tune it will make the same peak power as a dedicated e85 tune. It just ramps in slower so it will make less power under the curve. With the A10 I'd bet its not very noticeable because if how fast you get into the powerband but on the mt82 you can definitely feel the difference down low. On 91 your flex tune and 91 tune should make the same power.

 

[ChitownStang]

When did Lund stop doing Flex tunes? They did one for me in 2020 and my car lives on that tune. Very rarely do I switch over to my dedicated E85 or 93 tunes.

I think with 2021 models it stopped

 

[AZ18yote]

As was previously stated maf turbulence can affect flex tunes. That was the primary factor on the Steeda closed intake not being able to run correctly with flex tunes.

Tuning for e85 alone, no other changes is usually good for 30-40whp by itself. The flex should have the same peak power as a dedicated e tune, but the dedicated tune will be adding spark earlier with the assumed e % so you will get better power down low / sooner.

 

[Zrussian13]

When did Lund stop doing Flex tunes? They did one for me in 2020 and my car lives on that tune. Very rarely do I switch over to my dedicated E85 or 93 tunes.

Not sure when they stopped but I never used my 91/93 tune either. Same power on the flex tune. I did use my e85 tune when ever possible though. The extra timing down low helps make up for the gearing and lack of down low torque from the ohc engine.

 

[junits15]

Your flex tune should always be faster than the pump gas tune unless your putting ethanol free gas in. Even running e30 timing is better than 91/93. Down low you won't feel much difference unless your on a dedicated E tune but up top you will. Or at least you should if your tunes right. Are you running an aftermarket Intake? I know the turbulence on some can effect the maf reading and make the ethanol learning logic struggle but it's still workable if you do it right.

Also I wouldn't install an ethanol sensor on a returnless system. You'll probably be ok but I wouldn't want a restriction on the feed side of my fuel system.

I think you mean "your flex tune should be the same as your 93 tune unless using ethanol free gas"

All mustang stock tunes after 2011 are made for e10, so a properly running flex tune will be identical on 93 when compared to a 93 tune from the same vendor, unless that vendor has purposefully made their "93 only" tune to be for ethanol free gas.

the issue with flex on these cars is that the system was never designed to be a power adder. It’s based off the flex f150 coyote. It doesn’t really matter if you e content is slightly off from inferred in that scenario because it was never intended to be changing timing that much anyway. Fuel trims take up the slack, and as long as the car makes the same power it’s good.

Using it as a power adder is different, it needs to learn fast and precisely, which it doesn’t.

it’s a funky system, it’s great considering that it requires no additional sensors, but I wish it was more precise or that we could use a real sensor. It works exactly as ford intended it.

 

[Magnetic Stang]

I currently have a flex tune and each time I go from switching from 93 to E85, my car seems to do a few things it doesn’t while on 93.
I literally runs perfect on 93 and when switching fuels, when I come to a stop the car idles down to around 500 and feels like it’s going to stall but never does. On 93 it never does that.
Also when running 0-60ft, 1/8th mile and 60-120mph, it’s actually little slower. It doesn’t give you that “push you back into the seat feeling” like the car wants to keep pulling like it does on 93.
Could the timing, AFR and spark not be tuned correctly when it switches fuel?
Would having a designated 93 and E85 tune be a better option rather than flex?
Car literally feels like it’s losing power on 85.
Any suggestions would be greatly appreciated

I had a similar issue with mine. My setup was just a JLT CAI and exhaust. I ended up getting an updated tune (it was tuned for the JLT CAI) and went back to the stock airbox and K&N drop in filter and it's ran perfect ever since. Personally it seemed like it was a drivability issue with the JLT CAI on E85. It seemed ok driving but idling is when it showed up. Drop down to 500rpm and act like it was doing to die. If i let the clutch out slowly just to move the car (at a light or a drive thru) the rpm's would go up to 1000 or 1100 and hang there. None of this has happen once I took off the JLT CAI.

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