[geargambler]

I did some searching but couldn't really find anything that I was looking for. There are some ethanol sensors out there which output to a gauge. I know that ethanol content sensors come stock on flex fuel vehicles.

I remember some time ago people were using EGR to log air fuel ratio using the output from a wideband. Now with an innovate LC2 it will plug right into the USB port of the laptop and can be configured as it's own payload.

Has anyone played with an inexpensive ethanol sensor and piped the output into a payload in BE? Or something similar? It would be nice to know what is in our tanks given the variety of fuels that are available at the pumps!

[cgrey8]

The last I heard, the only FlexFuel sensor out there was the one used by GM. I think Ford might have also had a FF sensor, but it wasn't as useful. I could be mis-remembering this, but I think theirs was frequency based and GM's was voltage based making the GM sensor are simpler to work with.

Now here's where I'm going out of a limb that might break on me. So take this with a grain of salt...

This is old info but many mfgs since late 2000s went to inferring the ethanol content when the tank is filled and then simply remembering that percentage until the tank is refilled. Exactly how it infers the content, I'm not clear on, but I believe it has to do with running the fueling logic in a "quick response" mode. During this mode the EEC detects the tell-tale signs of either running very rich or very lean and adjusts much faster than regular Closed Loop Fueling logic. Once it gets in the ballpark, it remembers the rough adjustment it took to get fueling under control and uses that until the tank is refilled.

I wouldn't doubt if there's some broad assumptions like assume the fuel content is the same as it was last time unless there's engine behavior to question that. However this means if you go from E0 directly to E85, you might have a rough crank when the E85 hits the engine and runs the engine really lean. And likewise going back to E0 might have a very rich crank until the percentage is inferred and adjusted for.

While the sensor is "better" control, this is probably a decent strategy to use to avoid the heavy cost of the ethanol sensor given 90% of people in the US will use E10 even if E85 is available. And the few people that use E85 generally use it consistently instead of E10 because it's consistently cheaper in their area (or whatever the reason). The ones that use E85 just learn not to run the tank completely empty when transitioning to/from E85. That way the logic doing the ethanol detection doesn't have to make such a harsh jump.

But back to your question of if you can install one of these sensors, yes you can. And back 10 years ago, you could find the GM FF sensors being sold on eBay. Although back then they weren't cheap, even for a used one. Looking on eBay today, they appear to be quite affordable and significantly smaller than the old ones I was remembering. It appears a new GM sensor can be gotten for ~$20. What I don't know is if they are still voltage-based. The cheap cost of these sensors makes me wonder if perhaps the EPA cracked down on the practice of inferring ethanol content, forcing mfgs back to sensors. And due to economies of scale, forced them to design these much cheaper versions?

[skunk]

I don't anything about the sensors but if they output 0-5 volts........you can feed it to BE through the EGR. You just have to define the transfer function. I log a 3bar Map via EGR.

Personally......I would have more use for something giving me an octane level vs E content.

John

[ironmanisanemic]

Both the ford and gm sensors are frequency based. They use the frequency to derive ethenol % and pulse width to measure fuel temp. The gm one is usually used as it was more widely available, and uses more sensible values. The gm sensor uses 50hz to 150hz to directly correlate to ethenol %. The ford sensor goes from 50hz to 125hz so it requires more math to map the values. You can feed this output through a low pass filter to get an almost linear output of 0-5v. I've been toying with the idea of designing an open source converter that has 2 outputs that are analog to be able to log ethenol and fuel temp over a 0-5v signal and have it be completely linear. I had a functioning proof of concept, but haven't gotten past that point.

[ironmanisanemic]

This thread and related posts is a good starting point to understanding and getting a basic working controller going.

https://www.sr20-forum.com/nismotronic/ ... utput.html

[97ba9d]

although I started out in ford tuning I ended up doing stuff on Nissan at some point. In the GTR community, they make a box that allows them to use a GM ethanol sensor plugged into the egr. the signal converter allows them to run flex fuel on them. I would think this would be a good place to start, they are small things and could be mounted near the sensor.

[geargambler]

All great info in this thread so far. I did read that the output of the GM sensor was frequency based. I even read up on how someone used an audrino to output the values to a small LED display. I'll have to look for that box that the GTR folks are using. I think it would awesome to install the sensor and log the ethanol content via the EGR. Then the tune can be adjusted once you know the content. I can't imagine the low pass filter that ironmanisanemic mentioned would be that expensive, along with a 20 dollar sensor and some fuel hookups. The gauges that are out there come with a sensor, but the price tag is a bit steep. I also saw where someone used the gauge to output to a LED the ethanol content, then piped it back into his tuning device which adjusted for whatever the content was. That seemed pretty slick to me.

Still - even if the ethanol content is logged, is there a way to adjust automatically? or is it still going to be a manual step to make the adjustments? I'm using the quarterhorse and BE.

[jsa]

The Moates Superlogger has frequency inputs for logging. There is another thread on here about an issue with BE and superlogger that is being resolved.

As for automatically adjusting, that would require new code in the eec or superlogger.

[skunk]

I'm not able to wrap mind around the usefulness of this on an average street vehicle. I'm not saying it's not there....only I dont see it. If your constantly changing fuel and need fast correction ....maybe.

Your ECU already compensates. If your running 5% ethonol, the ECU will need to command around an average of around 14.34 to get the HEGO to switch. It will look like your running lean if you watch Lambse due to the new stoich ratio. In fact the ECU is giving you a proper mix ......this is called feedback control.

The process is a little slower to have the correction applied to open loop due needing Kam's to learn in closed loop. The learned correction cell as designated in the adaptive learning table and all learned correction is then applied from there to all non-learning cells. Nevertheless..... correction happens.

Sorry don't mean to be a buzz kill.....carry on ...I am open to learning.

John

[jsa]

I'm not able to wrap mind around the usefulness of this on an average street vehicle.

Not many of those around here.

Yes, a step change is only needed when the fuel tank is topped up.

The EEC is typically set to compensate for 25% max. There are enough fuel variations around that exceed that.

Driving round for half an hour waiting for fuel trims to update is not my idea of fun or very practical.

[cgrey8]

As he said, you don't want to wait around a long time for the EEC to learn what fuel you just filled up with. Assuming an extreme of filling an empty tank with E85 after running gasoline, a true FFV tune would be able to monitor the fuel ethnaol concentration and when a sharp change in content is detected, prepare for the transition of what might be an abrupt change as the old fuel works its way out of the fuel system and the new concentration begins hitting the injectors. As the DIY tuner using a non FFV tune, it would be nice to have an FFV sensor to know by how much to alter the tune by.

In factory FFV applications, returnless systems actually have an advantage here as the fuel the engine will crank with after a fillup will be the same fuel it's been running so whatever it has learned about the fuel it last filled up with will likely be OK to crank the engine. This will give the EEC a chance to detect the ethanol change and prepare for it. And being it'll know which direction the concentration is going, it'll be able to proactively enrich and bias in that direction as it detects changes (either via HEGO or via erratic engine running conditions).

On a return-style fuel system with a high flow aftermarket fuel pump to support boost, it's quite possible the old fuel is pushed right out of the system and engine cranking will occur on the new the new fuel making having an FFV sensor that much more important for the 1st crank after a fillup. Fortunately tank refilling usually occurs on a warm engine where E85 doesn't crank much differently than gasoline. So riding through the transition should be far easier than if the transition were occurring on a cold engine. But regardless whether the tune is FFV or not, E85 does not cold-crank well at all. Even with E60-70 range, it still takes noticeably longer on the starter to get the engine to turn over if the engine's been sitting outside and is trying to be started at subfreezing temps. The more radical the engine build, I would almost expect to exaggerate this...but I don't know that for sure.

As it relates to older tunes where you have to manually adjust the tune for your fuel content, there are static things built into tunes that are not adjusted by Closed Loop LAMBSE or learned KAMRFs such as these cranking PWs making it nearly impossible for a non FFV tune to handle the full range of E0-E85 effectively without some caveats. THE most important difference being the cranking PWs. As stated above, E85 already has issues cold cranking. Add less than optimal cranking PWs for E85, and you might just find you have an engine that won't crank at all without a shot of starter fluid to get the engine to turn over. Once the engine is running, I can't say that ethanol runs much different than gasoline, even with the engine cold...at least it didn't when I tested it years ago on the old stock Explorer 302 that used to be in the truck.

And from a performance standpoint, most people will likely also want to run different Open Loop/WOT lambdas and Spark tables depending on the ethanol content particularly if boosted. Depending on how boosted it is, even 93 octane may still have to run a spark advance well below MBT where E85 would tolerate a higher advance thus resulting in more power for the same shot of fuel...but E85 may require an even richer lambda to do that.

True FFV tunes have to deal with these issues dynamically. So having a sensor makes this work far easier. The DIY tuner playing the role of adjusting for different fuels will have to manually deal with this. Now it's not like you need 10 tunes. You could probably make a tune to handle from E0-E30. Then another for E35-55, and a third for E60-85. And if you are running an old GUFx or CBAZA, you could load these into a Quarterhorse and flip between them on the fly as needed using a switch or software. I think the QH can hold two 2/4-bank EEC-V tunes? I can't remember that detail.

Anyway point being, it's not reasonable to rely on the EEC's self-adjustment aspect to accommodate E0 to E85 without some caveats or issues. That said, there are Youtube vids of people that have claimed to run E85 100k+miles on a stock non-FFV vehicles. Whether they had issues or not, they didn't say. I recall one guy that donated his suburban for an engine tear-down so the mechanic making the video could detail what he found. And they claimed that the vehicle was NOT a FlexFuel and thus they "expected" to find ethanol-related problems...but didn't. So it's quite possible you could get an engine to use a single tune and run the gamut of E0-E85. But if that's the case, I'd still argue the engine is only tolerant of E85, not optimizing for it.

[skunk]

Jsa, .....your post reaffirms my thoughts.

If it's not street driven vehicle as it seems mine must be the only one that is .....then you are turning for power to begin with and likely the highest octane rating available to you. You are also not likely to rely on any sort of automatic adjustment for huge variations in fuel to protect your investment or leave power on the table. You tune for consistency based on the fuel available to you and are not likely going to be switching up without comprehensive testing. Therefore there is no need to drive for half an hour waiting for the ECU to learn anything. You already dialed everything in and ajustment will be minimal.

Cgrey8....you bring up valid points for an average consumer street driven vehicle. But again it's not likely the average Motorhead I going to stray from his beverage of choice. Up here corn is still for eating mostly and the fuel I encounter is labeled that it may contain up to 10%. My truck is a Flex fuel vehicle and gets fuel from the same pump as my old junk. Even if I had a choice to run E85 on my truck....why bother....there is no benefit for that vehicle except making it use more fuel for the same work.

FFV programming was born out necessity for manufacturing conforming to the social justice movement toward the use alternative fuels. Problem being..... availability of those fuels was not uniform. They needed the vehicles to be able to run on a wider spectrum of fuel and to adjust quickly since the potential of the fuel in the tank to be inconsistent is very high. You can't fix stupid, you can only try and protect against it seems to be appropriate here.

Maybe it's my age here but relying on technology to do all the thinking isnt the answer.

I'm out....good luck to the OP. It's fantastic to challenge yourself, I hope you learn a great deal from it

John

[cgrey8]

Cgrey8....you bring up valid points for an average consumer street driven vehicle. But again it's not likely the average Motorhead I going to stray from his beverage of choice...

If it's a race vehicle (amateur or pro), I would tend to agree. but if it's a daily driver or even a fun weekend vehicle owned by someone that likes to tinker and experiment, then testing out different blends might be something they'd be interested in trying particularly if there's a chance of a financial benefit in doing so. That said with the price of gasoline right now, it's not likely that E85 is going to compete realistically with anything but Premium. And running the numbers in my Ethanol Calculator, Premium in my area still has a sight economic advantage. However I live in an area where 93 octane is available. In areas where the highest octane is 91, that might not be the case. The higher octane benefits of E85 (or even a blend of E50) might be enough to make the blend a little cheaper thanks to being able to bump spark advance way up from what 91 Premium will tolerate.

...Up here corn is still for eating mostly and the fuel I encounter is labeled that it may contain up to 10%. My truck is a Flex fuel vehicle and gets fuel from the same pump as my old junk. Even if I had a choice to run E85 on my truck....why bother....there is no benefit for that vehicle except making it use more fuel for the same work...

I get that and understand exactly what you are saying here. With most FFVs also being able to run Regular 87 octane, there's zero benefit, as far as I can tell, in running E85 at least in my area. Perhaps up in Iowa where "Big Corn" lives, the E85 is subsidized enough that it makes it cheaper up there even for a production vehicle capable of 87 octane? I couldn't say.

...FFV programming was born out necessity for manufacturing conforming to the social justice movement toward the use alternative fuels. Problem being..... availability of those fuels was not uniform. They needed the vehicles to be able to run on a wider spectrum of fuel and to adjust quickly since the potential of the fuel in the tank to be inconsistent is very high...

I've often been both an advocate and an opponent of ethanol fuel. As a fuel, Ethanol isn't that bad. It certainly burns cleaner in the engine and when the vehicle is properly outfitted to tolerate Ethanol, it makes for an OK fuel despite it having a lower energy density (techie way of saying you have to fill up more often). As long as its per-volume price is low enough to offset that (including the inconvenience), I rather like having choice.

But that's where the rub comes. When politics started demanding/incentivizing/coercing mfgs to make FFVs domestically, that raised the price at the dealership for all vehicles. Mfgs knew FFV wasn't a selling point so the cost of FFV had to amortized across the entire fleet of new vehicles. Whether that was done directly by the Mfgs or via the gov't in the form of FFV tax credits, the result is the same. It's the feds demanding consumers spend money on something they didn't want or ask for. Then in 2007, they doubled-down with the Renewable Fuels Act where the gov't demanded that X amount of Ethanol be blended into the fuel supply. And the law was so poorly written and made so many bad assumptions, it was unsustainable and quickly ran up against the 10% "blend wall." But stubborn politicians refusing to admit when they were wrong continued to pound the sledge hammer at the square peg stuck in the round hole..despite the evidence of their own stupidity staring right back at them. Both sides of the isle must claim blame for this fiasco.

So all this has just soured the average Joe on the thought of Ethanol in their fuel because they were never given a choice in the matter. But eventually more level-headed politicians did get in office. And as a result of reduced regulations and the ending of Ethanol subsidies, people now have E0 available to them again. In my area, numerous gas stations have at least one E0 pump. It costs significantly more, but for boats, lawn mowers, and other small engines, it's worth the cost to keep the Ethanol out of them.

...Maybe it's my age here but relying on technology to do all the thinking isnt the answer...

In the case of FFV vehicles and FFV tuning, I don't find the concept undercutting the human. It's no different than the natural progression of the EEC to get transmission control, EDIS ignition control, Variable Valve Timing control, ABS-interface monitoring, dash control, fuel tank pressure monitoring, fuel line pressure monitoring/fuel pump speed control, etc etc etc. It's just another of the many dynamics the computer has to track and maintain.

But when attempting to run higher Ethanol blends in non-FFV cars controlled by non-FFV EECs, that's where the human MUST take a more active role and do what the computer wasn't ever programmed to do (hence my suggestion of having multiple tunes for different blends). If you are one of those taste-testers that strays from the beverage of choice, and don't mind trying alternate blends of Ethanol-laced fuel, I just wanted to point out the things that are important to be aware of.

And like I said, for those with high performance street vehicles living in areas where 91 octane is their Premium, there's a very likely performance incentive to use higher Ethanol blends. So again, I tend not to hate the Ethanol fuel. But I do rather detest the politics that has surrounded it.

[geargambler]

But when attempting to run higher Ethanol blends in non-FFV cars controlled by non-FFV EECs, that's where the human MUST take a more active role and do what the computer wasn't ever programmed to do (hence my suggestion of having multiple tunes for different blends). If you are one of those taste-testers that strays from the beverage of choice, and don't mind trying alternate blends of Ethanol-laced fuel, I just wanted to point out the things that are important to be aware of.

And like I said, for those with high performance street vehicles living in areas where 91 octane is their Premium, there's a very likely performance incentive to use higher Ethanol blends. So again, I tend not to hate the Ethanol fuel. But I do rather detest the politics that has surrounded it.

Again, all of the posts are appreciated. This is another great discussion around the care and feeding of our cars / trucks! I think what I was really looking for is quoted above. There does need to be manual intervention when the blend changes significantly. The suggestion of having the three calibrations for a range of blends is fantastic. I did read that in another thread. I'm still very interested in what I had originally stated about logging the ethanol content using the 20 dollar GM sensor. Through the logging we could quickly detect what the blend ACTUALLY is and load the matching calibration.

My hope is in seeing a low cost logging solution. I could drop the big bucks on a zietronics (or similar OOTB solution), but what fun is that? If we had a DIY solution that took advantage of a 20$ ebay sensor (and other assorted magic) that output a reliable blend, I think the solution would get popular very quickly.

[cgrey8]

If the sensor is is 0-5v, then the options are a whole lot simpler. You can either use an available EEC input (i.e. the EVP sensor input) or external A/Ds like DataQ or Moates Superlogger. Incorporating the SL into softwares like BinaryEditor are still being worked on, the only existing solution that I know of that works WELL with BE is the DataQ. It allows numerous analog values to be captured, displayed, and logged at runtime alongside the Quarterhorse's payload items. The hope is the Superlogger will be able to do this as well. Although I believe the DataQ is still a bit cheaper. The benefit of the Superlogger would be the wireless aspect. I haven't checked the DataQ website in some time. For all I know, they have a Bluetooth solution too. If they do, I'd be interested in checking it out to see how well it'd work with BE.

If the FFV sensor is frequency-based, then the solution for datalogging it are more limited just because the details of monitoring a frequency-based sensor are a bit more complicated and require a more "active" role and configurability on the part of the monitoring hardware...of which I believe the Superlogger has, but the DataQ does not have.

Now in the case of 3 tunes to cover the gamut of 0-85% ethanol, it probably would be good enough to simply guesstimate without an actual sensor. If you know you are filling with E85 and the tank is 1/2 full of E10, then do the math based on how much E85 you fill it with. There are spreadsheets out there to do that estimation. But I agree, it'd make me feel better being able to datalog it...if anything just to get a feel for how much the overall blend changes as fillups are done and to get a visual of how quickly the blend stabilizes. Is it sufficiently blended upon fill or is the engine getting a hodge-podge of blend concentrations for the first 5-10 minutes of drive after a fill-up? Logging the ethanol concentration in the fuel line would give you this kind of insight that might or might not be relevant.

The other option is, take a guess at the right tune. If it works, roll with it. If it doesn't, then put the other likely candidate in OR tweak your template tune to work. If you do a lot of ethanol swapping, you'll eventually get good at knowing what needs to change and what doesn't. This also assumes you don't mind a laptop as a travel parter on a regular basis.

[geargambler]

I don't mind a laptop as a travel partner. it has a much nicer dashboard than my stock one anyway!

The FFV sensors are certainly frequency based. They did this so that they could also include temperature, which is a function of the pulse width of the frequency. So there's really two parts - content and temperature.

Good suggestions on the guestimate and spreadsheet. I figure if the laptop is already there, Excel will be there too :)