E85 Fuel Blending

[Ta2dResqr]

Has anyone checked the accuracy on the Fuel-It bluetooth sensor?

https://forums.nasioc.com/forums/showthread.php?t=2810122 This link is showing a DIY sensor (they use it to link to COBB) with 1% claimed accuracy.

 

[SilvererSHO]

Fuel it only makes the Bluetooth adapter. The sensor itself is a GM sensor. I do believe moisture throws it off and I have seen level climb towards the end of the tank when the weather fluctuate’s in the cold. Ermmm Texas cold. Minnesota is just a little a colder I hear?

Yup, I realize it's just the adapter. So all calculations are done by the sensor and the adapter just relays the info? Or is there more to it? It looks like it works with a few different sensors. Pretty steep price if all it is is an app and a bluetooth adapter.

Yessir, MN is just a wee bit colder. It's the worst environment you could have for E-85 also. Hot humid summers and cold winters. Your E-85 vehicle better be a daily driver as it doesn't last long sitting in a vented to atmosphere tank.

 

[DadMobile]

Yup, I realize it's just the adapter. So all calculations are done by the sensor and the adapter just relays the info? Or is there more to it? It looks like it works with a few different sensors. Pretty steep price if all it is is an app and a bluetooth adapter.

Yessir, MN is just a wee bit colder. It's the worst environment you could have for E-85 also. Hot humid summers and cold winters. Your E-85 vehicle better be a daily driver as it doesn't last long sitting in a vented to atmosphere tank.

It is expensive no doubt. It only takes about 20 minutes to install and you don’t have another gauge.

As far as MN goes, I have done a little ice fishing up there. I love the out doors up in those parts and I can only imagine how E85 would go.

 

[ButtonPuncher]

But Ford does not use ethanol sensors, even on actual flex fuel vehicles. Instead they have some convoluted scheme that works by monitoring changes in fuel trims following a fill up. Guys are using it on mustangs but I haven't heard of anyone doing it on a taurus and honestly I wouldn't trust it anyway.

stripsho and FiveLeeter918, THANK YOU! I've been pulling my hair out trying to figure out where the ethanol sensor is on the Taurus. And trying to figure out how they measure it. I wanted to figure out if it could be added to the SHO.

I was thinking of things in AFR. 14.7 for gas and 9.8 for E85. But what you're saying is that they are using Lambda. 14.7=9.8=1.0 Lambda. So on a power pull, if the target is 0.8 Lambda, then it just trims the fuel to reach that target. It doesn't care if it's gasoline or propane, it's just looking for the right amount of oxygen in the exhaust. NOW I GET IT!

Thanks guys, I haven't had an A HA! moment in a while.

It is a bit ingenious on Ford's part. Instead of implementing a separate sensor, just use one you've already got. And with states all being different, some E0, some E10, and now E15, it makes sense. I guess the only limit on which cars are Flex Fuel is the injector and fuel pump sizing.


Thanks,
Ben

 

[FiveLeeter918]

stripsho and FiveLeeter918, THANK YOU! I've been pulling my hair out trying to figure out where the ethanol sensor is on the Taurus. And trying to figure out how they measure it. I wanted to figure out if it could be added to the SHO.

I was thinking of things in AFR. 14.7 for gas and 9.8 for E85. But what you're saying is that they are using Lambda. 14.7=9.8=1.0 Lambda. So on a power pull, if the target is 0.8 Lambda, then it just trims the fuel to reach that target. It doesn't care if it's gasoline or propane, it's just looking for the right amount of oxygen in the exhaust. NOW I GET IT!

Thanks guys, I haven't had an A HA! moment in a while.

It is a bit ingenious on Ford's part. Instead of implementing a separate sensor, just use one you've already got. And with states all being different, some E0, some E10, and now E15, it makes sense. I guess the only limit on which cars are Flex Fuel is the injector and fuel pump sizing.


Thanks,
Ben

Pretty much. In a nutshell, anything port injected (standard fuel rail with in-tank pump(s)) can use Flex Fuel logic from the factory, but not all is activated from the factory. For example, the F-150 5.0L comes with factory flex fuel, but the Mustang 5.0L does not. It does have the logic built into the PCM, but being a performance vehicle they chose not to activate it. Exactly why, I'm not sure, but it may have something to do with advertised fuel efficiency and the average EPA efficiencies they are required to comply with as a manufacturer.

And yes the manufacturer uses multiple fuel tables, the knock sensors, and lspi adjustments to determine the rough octane of the fuel and develops an "Octane Adjustment Ratio" number that will dictate which fuel/spark tables it references in different instances. It isn't able to adjust for stoichiometric changes, but uses fuel trims and the factory wideband upstream oxygen sensors to adjust AFR on the fly and it can compensate up to 25% fueling before it exceeds the table potential and pops a CEL.

There are a occasionally tuners that try to hide their lambda values but changing the lambda readout instead of the stoich readout, therefore keeping the lambse at 1.00 at all times as the "base point" and then any variance is used to tell how far off commanded it is. Makes it easier to graph, but also harder to keep track of IMO when reviewing logs.

 

[Ta2dResqr]

Pretty much. In a nutshell, anything port injected (standard fuel rail with in-tank pump(s)) can use Flex Fuel logic from the factory, but not all is activated from the factory. For example, the F-150 5.0L comes with factory flex fuel, but the Mustang 5.0L does not. It does have the logic built into the PCM, but being a performance vehicle they chose not to activate it. Exactly why, I'm not sure, but it may have something to do with advertised fuel efficiency and the average EPA efficiencies they are required to comply with as a manufacturer.

And yes the manufacturer uses multiple fuel tables, the knock sensors, and lspi adjustments to determine the rough octane of the fuel and develops an "Octane Adjustment Ratio" number that will dictate which fuel/spark tables it references in different instances. It isn't able to adjust for stoichiometric changes, but uses fuel trims and the factory wideband upstream oxygen sensors to adjust AFR on the fly and it can compensate up to 25% fueling before it exceeds the table potential and pops a CEL.

There are a occasionally tuners that try to hide their lambda values but changing the lambda readout instead of the stoich readout, therefore keeping the lambse at 1.00 at all times as the "base point" and then any variance is used to tell how far off commanded it is. Makes it easier to graph, but also harder to keep track of IMO when reviewing logs.

Is this Logic in the SHO PCM? I see mixed reports on people being able to activate it using HPTuners on various other Fords.

 

[stripSHO]

stripsho and FiveLeeter918, THANK YOU! I've been pulling my hair out trying to figure out where the ethanol sensor is on the Taurus. And trying to figure out how they measure it. I wanted to figure out if it could be added to the SHO.

I was thinking of things in AFR. 14.7 for gas and 9.8 for E85. But what you're saying is that they are using Lambda. 14.7=9.8=1.0 Lambda. So on a power pull, if the target is 0.8 Lambda, then it just trims the fuel to reach that target. It doesn't care if it's gasoline or propane, it's just looking for the right amount of oxygen in the exhaust. NOW I GET IT!

Thanks guys, I haven't had an A HA! moment in a while.

It is a bit ingenious on Ford's part. Instead of implementing a separate sensor, just use one you've already got. And with states all being different, some E0, some E10, and now E15, it makes sense. I guess the only limit on which cars are Flex Fuel is the injector and fuel pump sizing.


Thanks,
Ben

It's not quite as simple as just accepting any mix of ethanol and letting the fuel trims fly. There's an "inferred" ethanol percentage. After a fillup, the computer watches for changes in fuel trims. If the trims start tracking higher it infers a higher amount of ethanol in the mix. It guesses the alcohol content then it adjusts the target stoich ratio accordingly, thereby restoring fuel trims back to normal, and also adjusts timing maps etc.

 

[ButtonPuncher]

OK. Thanks everybody. That makes sense. It sounds like it essentially needs to shift to a different range once it can't trim enough. Yeah, i'm sure that it's a regulation/EPA thing. Every "range" needs to be certified by the EPA and it probably takes tons of testing and time to get each setup certified.

I'm guessing that Ford had determined that it's not worth the money for the larger fuel pump and injectors on the budget cars, and that on the performance cars, most people don't run E85 which is viewed by uninformed people as a eco-friendly fuel, not a performance fuel.

Neither my '06 Mazda 6 3.0L or my '11 Mazda 6 3.7L could be tuned. They used an oddball Mitsubishi ECU that was different from the Fords using the same motor. It'll be awesome to have a car that can be tuned to it's full potential.

 

[ButtonPuncher]

One other thought... Could a useless input like the ambient air temp sensor (not IAT) be used to tell the PCM what the ethanol level is and then change fuel maps that way? So if the ethanol sensor outputs a 0-5V signal, because the ambient temp sensor is typically a NTC resistor, use an Arduino and a digital potentiometer to generate a proportional resistance and make it effectively read ethanol instead of temperature? So 10 percent ethanol would show as 10 degrees, 85 percent would be 85 degrees, etc. This is all assuming that something like the climate control doesn't use the AAT sensor for something. LOL!

If anything it'd be a nice way to datalog actual ethanol content.

Just a geek thinking out loud.

 

[ButtonPuncher]

Plus it'd be a stealth way to have an ethanol content display.

Passenger: It's not 19 degrees outside?!?
You: Nope, but my ethanol content is 19%!


(Sorry for the additional post, meant to add it to the previous one. Doesn't seem like an end user can delete a post, or I haven't figured it out yet.)