E85 Questions

[stangman638]

There is logic built into the sw that the PCM uses that, if turned on, allow the PCM to make adjustments based on an "inferred" ethanol content in the fuel. The inferred calculation is based on what the stock wideband o2's are reading in regards to fuel trims. This process "inferred ethanol content", is not an exact reading of the ethanol content compared to other mfg's that incorporate actual ethanol sensors. This is why the ethanol percentage we see can seem to be slow to react and also why tuners have to be cautious in flex fuel tunes and can't be too agressive with timing at part throttle or timing at lower rpm, high load inputs. The flex fuel tables for the F150 and the mustang are essentially the same they just aren't active in the stock mustang tunes.

E85 only or commonly referred to as E85 "race" tunes use a hard input of stocih, meaning the tune is indicaitng that an 85% ethanol blend fuel will be only used in the car. Tuners can be more agressive, especially at part throttle and erlier in the torque curve on adding more timing. That's why E85 only tunes often feel stronger than flex tunes, especially in everyday stoplight to stoplight driving. I strongly prefer the feel of the E85 only tune but also understand that running this tunes means I am responsible for finding and using E85 with 85% ethanol content.

The alc% shown on Ngauge I learned isn't all the accurate either in the flex tune, I was showing nearly 85% on my Ngauge, but a buddy that has an ethanol sensor got gas at the same station and its really 75-76%. I was told not to load the E85 tune unless I have 75% ethanol, finding true E85 at a pump isn't likely at most stations.

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[Loki-GT]

@Loki-GT

I'm almost positive all stations say that. Winter blend is about 51% then once they switch to summer blend it starts to rise. I have 56% in my tank now with no issues. AFR is around 11.3 since it's not full e85 and knock sensor rarely goes positive no more the +1.50 and see as much as -9.99 knock, 0 drivability issues. If you have the FF tune you'll be fine to do it now.

I went back to the station with 0 miles till empty showing up 2 miles before I got there. I idled for another 10 minutes and then shut the car off, put 8 gallons of E85 in and waited, AFR dropped to 9.7, I installed the E85R tune and drove it for 20 minutes before doing a WOT and logging it. It felt fantastic, when it hit 2nd it spun into 3rd where it spun a bit more. There is a definite difference between stock and E85 and I'm guessing I got pretty close to actual E85 with the AFR reading, but in another thread they said it could be off. I heard the NGauge can give AFR readings, wouldn't they be the same as the one the car gives since it's reading from the same source?

 

[Bluemustang]

I went back to the station with 0 miles till empty showing up 2 miles before I got there. I idled for another 10 minutes and then shut the car off, put 8 gallons of E85 in and waited, AFR dropped to 9.7, I installed the E85R tune and drove it for 20 minutes before doing a WOT and logging it. It felt fantastic, when it hit 2nd it spun into 3rd where it spun a bit more. There is a definite difference between stock and E85 and I'm guessing I got pretty close to actual E85 with the AFR reading, but in another thread they said it could be off. I heard the NGauge can give AFR readings, wouldn't they be the same as the one the car gives since it's reading from the same source?

The Ngauge reading should be the same, yes. I wouldn't go by readings. If you are using an E85 tune you must test it yourself.

 

[shogun32]

I think I should put a 'beer tap' in the side wall of the gas tank, "pull a glass" (ideally with little froth/head) and measure that way. Swirl it around, take a whiff... Does ethanol have a notable aroma and after-taste?*JK*

Is everyone running up-sized injectors or do the stock ones flow enough to keep up for 'normal' non-supercharger applications?

 

[Zelek]

I think I should put a 'beer tap' in the side wall of the gas tank, "pull a glass" (ideally with little froth/head) and measure that way. Swirl it around, take a whiff... Does ethanol have a notable aroma and after-taste?*JK*

Is everyone running up-sized injectors or do the stock ones flow enough to keep up for 'normal' non-supercharger applications?

2018+ have bigger injectors already so you're fine while N/A.

 

[18 Smoke]

2018+ have bigger injectors already so you're fine while N/A.

They actually have smaller port injectors, but they have 8 more with the DI and that extra fuel gives you all you need for N/A power

 

[MustangPP1]

The alc% shown on Ngauge I learned isn't all the accurate either in the flex tune, I was showing nearly 85% on my Ngauge, but a buddy that has an ethanol sensor got gas at the same station and its really 75-76%. I was told not to load the E85 tune unless I have 75% ethanol, finding true E85 at a pump isn't likely at most stations.

So you can load straight E85 tune when its above 75%?

 

[stangman638]

So you can load straight E85 tune when its above 75%?

That's what Dakota told me yes.. 75% min.. I guess they left some cushion in the tune.

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