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Stock fuel system e85 tuning
- Thread starter ZFGracing
- Start date
Most modern vehicles use LINEAR or A/F sensors
Regardless of the fuel mix the LINEAR SENSOR input will adjust fuel to maintain stoichiometry
When using ethanol blends fuel trim PLUS PERCENTAGES will increase as the amount of ethanol increases
Their is no inline ethanol sensor on many FLEX FUEL vehicles with GDI & PFI
In some cases the same injectors & other components are the same for FLEX FUEL & NON FLEX FUEL VEHICLES
The only difference is the software (PROGRAMMING)
They just use linear sensors to maintain stoichiometry![[thankyou]](/images/smilies/icon_smile_thankyou.gif "Thank you [thankyou]")
Regardless of the fuel mix the LINEAR SENSOR input will adjust fuel to maintain stoichiometry
When using ethanol blends fuel trim PLUS PERCENTAGES will increase as the amount of ethanol increases
Their is no inline ethanol sensor on many FLEX FUEL vehicles with GDI & PFI
In some cases the same injectors & other components are the same for FLEX FUEL & NON FLEX FUEL VEHICLES
The only difference is the software (PROGRAMMING)
They just use linear sensors to maintain stoichiometry
Car is not a "flex fuel" vehicle either. All software calibrated that tricks the ECU.
Most modern vehicles use LINEAR or A/F sensors
Regardless of the fuel mix the LINEAR SENSOR input will adjust fuel to maintain stoichiometry
When using ethanol blends fuel trim PLUS PERCENTAGES will increase as the amount of ethanol increases
Their is no inline ethanol sensor on many FLEX FUEL vehicles with GDI & PFI
In some cases the same injectors & other components are the same for FLEX FUEL & NON FLEX FUEL VEHICLES
The only difference is the software (PROGRAMMING)
They just use linear sensors to maintain stoichiometry
Regardless of the fuel mix the LINEAR SENSOR input will adjust fuel to maintain stoichiometry
When using ethanol blends fuel trim PLUS PERCENTAGES will increase as the amount of ethanol increases
Their is no inline ethanol sensor on many FLEX FUEL vehicles with GDI & PFI
In some cases the same injectors & other components are the same for FLEX FUEL & NON FLEX FUEL VEHICLES
The only difference is the software (PROGRAMMING)
They just use linear sensors to maintain stoichiometry
Are these cars widebands? I really really hope so since they are turbod.
Y'all are missing the point. Yes, of course a modern vehicle can correct for changes in ethanol content. Where I live, I can get 93 fuel only, 93/10% ethanol, and in the summer 93/30% ethanol. You can also get e85. I'm not sure about straight e85, but all of these will run fine in an ST. However, this thread started with talking about using various fuels to extract max power- not just to use knock correction and lambda sensors to achieve closed loop stoichiometric fueling.
The holy grail for a buyer of a tune would be to have a tune that would not just allow the vehicle to drive down the road, but to be able to maximize performance when a potentially more powerful fuel is present. For example, I'm wanting to race and don't care about mileage, I plug e85 in the tank, and bang...6 more lbs of boost and adequate timing and fueling to match. Similar to what you'd get with an e85 tune without my having to download different maps and deal with mixing and measuring. After all, even e85 is 51-85% ethanol depending on the season. That would be a real "flex fuel" tune.
I don't have knowledge about Ford's ECU, but I do have insight into tuning flex fuel with a Haltech. That type of tune allows correction maps which use a content sensor to determine the percentage of ethanol. Using that you can alter timing, fueling, and boost via maps so as to interpolate and maximize the performance automatically. So, when I first posted about Flex fueling to ZFG, I was more curious as to how or whether this could be accomplished when he said he was looking into a flex tune.
Since there isn't an alcohol content sensor on the ST, the only way I can think of is to use the fueling correction strategies (short and long term) to "infer" the amount of ethanol present. We can certainly assume Ford does this to do stoich, but even so, do there exist correction maps for timing, fuel, and boost in the stock ECU that can take advantage? If not, you can't do a true "flex fuel tune".
The holy grail for a buyer of a tune would be to have a tune that would not just allow the vehicle to drive down the road, but to be able to maximize performance when a potentially more powerful fuel is present. For example, I'm wanting to race and don't care about mileage, I plug e85 in the tank, and bang...6 more lbs of boost and adequate timing and fueling to match. Similar to what you'd get with an e85 tune without my having to download different maps and deal with mixing and measuring. After all, even e85 is 51-85% ethanol depending on the season. That would be a real "flex fuel" tune.
I don't have knowledge about Ford's ECU, but I do have insight into tuning flex fuel with a Haltech. That type of tune allows correction maps which use a content sensor to determine the percentage of ethanol. Using that you can alter timing, fueling, and boost via maps so as to interpolate and maximize the performance automatically. So, when I first posted about Flex fueling to ZFG, I was more curious as to how or whether this could be accomplished when he said he was looking into a flex tune.
Since there isn't an alcohol content sensor on the ST, the only way I can think of is to use the fueling correction strategies (short and long term) to "infer" the amount of ethanol present. We can certainly assume Ford does this to do stoich, but even so, do there exist correction maps for timing, fuel, and boost in the stock ECU that can take advantage? If not, you can't do a true "flex fuel tune".
You do not need a sensor besides the wideband. This is assuming the ECU can support it. A lot of time there is a flex fuel patch hp tuners has to apply and then you have access to more tables.
For example.
With dodge a patch is applied and in the spark table there is an added table that depending on percent of alcohol that the wide bands infer is the amount of timing the car has. I’d assume if capable you’d be able to adjust turbo boost in a similar way in the tune if the ecu is flex fuel capable. Or maybe it is capable and hp tuners needs to add tables or a patch.
even tables for fuel mass are in the Hemis depending on alcohol percent are adjusted.
same with power enrichment. At 85% alcohol I have the car 65 percent more rich than I do on 0 percent alcohol. Of course e 50 would be somewhere in between that I have set in the tune.
STFT are still in good range if the tuner spends time dialing in the injectors properly since fuel mass is slightly changed depending on alcohol content. LTFT aren't the greatest thing to see in a flex vehicle. But if you are only seeing 1 to 3% LTFT in spots it isn't the end of the world as STFT will be able to properly adjust.
Long story short a wideband is all you need to tune Flex Fuel if the ECU can handle it. There can be a debate is inferred as good as a sensor.
I see your point this post was started to show e85 in a stock fuel system and compare power to other tunes without upgrading. Which is great information and glad I found that information. This thread has slightly been derailed.
My guess is the PCM is Flex Fuel capable we just need to wait for hp tuners to open up the tables or create a patch or it'd be offered already.
For example.
With dodge a patch is applied and in the spark table there is an added table that depending on percent of alcohol that the wide bands infer is the amount of timing the car has. I’d assume if capable you’d be able to adjust turbo boost in a similar way in the tune if the ecu is flex fuel capable. Or maybe it is capable and hp tuners needs to add tables or a patch.
even tables for fuel mass are in the Hemis depending on alcohol percent are adjusted.
same with power enrichment. At 85% alcohol I have the car 65 percent more rich than I do on 0 percent alcohol. Of course e 50 would be somewhere in between that I have set in the tune.
STFT are still in good range if the tuner spends time dialing in the injectors properly since fuel mass is slightly changed depending on alcohol content. LTFT aren't the greatest thing to see in a flex vehicle. But if you are only seeing 1 to 3% LTFT in spots it isn't the end of the world as STFT will be able to properly adjust.
Long story short a wideband is all you need to tune Flex Fuel if the ECU can handle it. There can be a debate is inferred as good as a sensor.
I see your point this post was started to show e85 in a stock fuel system and compare power to other tunes without upgrading. Which is great information and glad I found that information. This thread has slightly been derailed.
My guess is the PCM is Flex Fuel capable we just need to wait for hp tuners to open up the tables or create a patch or it'd be offered already.
ZFG does offer a "FLEX FUEL TUNE"
They do not require a separate sensor
So it is possible they use the linear sensor input & fuel trim to determine ethanol content
That is indeed possible
FYI : "LINEAR" sensors are wideband sensors
They are referred to as linear sensors because their pumping current is linear based on A/F ratios
All ford products use various iterations of the Bosch Linear (wideband) sensors upstream of the cats
However I suggest you ask ZFG how in fact they accomplish their Flex Fuel calibrations
They do not require a separate sensor
So it is possible they use the linear sensor input & fuel trim to determine ethanol content
That is indeed possible
FYI : "LINEAR" sensors are wideband sensors
They are referred to as linear sensors because their pumping current is linear based on A/F ratios
All ford products use various iterations of the Bosch Linear (wideband) sensors upstream of the cats
However I suggest you ask ZFG how in fact they accomplish their Flex Fuel calibrations
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Once again, I'm talking about being able to maximize performance. Period. Yes, you can use the lambda sensor to adjust fueling. But, can you adjust timing and boost on the fly in the Ford ECU to do this? Are there correction maps available for those variables as well? If Ford had those maps, then I would expect to be able to fill the tank with e85 and see timing and boost target numbers change- resulting in a lot more performance, but it doesn't happen, and in that case, we wouldn't need a "tune". In order for it to happen (and you're right, perhaps it's possible), then any tuner who can actually do that has no need to sell multiple performance mappings. That's what I'm referring to as a true "flex fuel" tune.
As far as asking ZFG how in fact they accomplish their Flex Fuel calibrations....isn't that exactly what I'm doing???
As far as asking ZFG how in fact they accomplish their Flex Fuel calibrations....isn't that exactly what I'm doing???
Not sure about Ford's ECU but my point of my post is that the ATS can achieve exactly what MikeWolfe.. It's been done on other vehicles that are not flex fuel cars as well. Yes, it will gain more power as well vs a 91 tune. About 20whp running full E85 vs 91. No sensor was needed or injectors or fuel pump, just a tune. No need to change maps either. Just gas up, drive around, will automatically adjust to the new fuel and bam, more power.
Can this be do-able on the ST? We have yet to see but wouldnt surprise me if it does.
Can this be do-able on the ST? We have yet to see but wouldnt surprise me if it does.
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ZFG does offer a "FLEX FUEL TUNE"
They do not require a separate sensor
So it is possible they use the linear sensor input & fuel trim to determine ethanol content
That is indeed possible
FYI : "LINEAR" sensors are wideband sensors
They are referred to as linear sensors because their pumping current is linear based on A/F ratios
All ford products use various iterations of the Bosch Linear (wideband) sensors upstream of the cats
However I suggest you ask ZFG how in fact they accomplish their Flex Fuel calibrations
They do not require a separate sensor
So it is possible they use the linear sensor input & fuel trim to determine ethanol content
That is indeed possible
FYI : "LINEAR" sensors are wideband sensors
They are referred to as linear sensors because their pumping current is linear based on A/F ratios
All ford products use various iterations of the Bosch Linear (wideband) sensors upstream of the cats
However I suggest you ask ZFG how in fact they accomplish their Flex Fuel calibrations
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