FlexFuel over Straight E85 on EcuTeK, why is it better?

[jamesm]

Originally Posted by FA20Club.com

Test your theory @WOT running a pump map on E85 and let us know your results in both NA and FI trim. Or moreso with a 60/40 blend or even a 50/50. Because Ive told many people in the past that is you run E85 on pump and didnt have time to swap maps your car will drive normally. But @WOT youll still be well short of your fueling needs. And besides the fact that your car can adjust fuel trims on the fly that doesnt help you when you blend varies by more than 10% fuel. Nor does it help you when you need to make significant timing adjustments based on an unknown amount of ethanol percentage. Running pure on either side of the blend isnt what this thread should be about. In some cases you will need to run a blend and will find yourself running a blend for whatever reason and always being able to have a safe basis of doing so. I have customers who drive their cars from across multiple states on a regular and find themselves mixing and matching fuels on their trips.

if i were to disable long term trims in the d range, that would be accurate, but i haven't. whatever your fueling error is in that bucket will carry in to open loop. this is well understood, and works, as @shiv demonstrated quite effectively in the other post he made. yes they take time to settle, and it's not ideal, but the correct amount of fuel still ends up in the right place.

[DJCarbine]

I supposed a good question to ask is if optimal cam phasing is different between E10 and E85 fuel, and if ecutek flexfuel has the ability to interpolate as it does with the fueling/ignition

[FA20Club.com]

Originally Posted by jamesm

if i were to disable long term trims in the d range, that would be accurate, but i haven't. whatever your fueling error is in that bucket will carry in to open loop. this is well understood, and works, as @shiv demonstrated quite effectively in the other post he made. yes they take time to settle, and it's not ideal, but the correct amount of fuel still ends up in the right place.

What I asked was have you tested that at WOT yet. As far as adjusting goes thats fine to a certain extent once you start using theother enrichment tables. Without them is what i asked you test. Suchas rom a non E85 tune with ethanol in the tank and let me know how it reacts. Because if it runs the same then a specific tune for ethanol in this car is completely unnecessary is what youre trying to say then. Correct me if im wrong. What do you feel on cam phasing, ignition and cranking on various percentages. Fuel is only a fraction of the puzzle. And ethanol content changes with temperature as well. If you install ECA in your car andmonitor it from cold start to fully warmed condition youll notice a swing of about 5%. Not granted thats not allot. But its enough at certain levels to make you go back to tweaking your cranking tables. Esspecially for those in colder areas than Florida. Im sure Bill@Delicious has setup his flex fuel tables as well with these factors in mind. Im sure Shiv has tested as much as he can with what he has. But the trend lately seems to whatever options aren't available or cant be added arent needed. Why are you coding in a boost cut. that seems to be a more important parameter at this point for all the turbo guys out there. I think that should be Delicious next thread. That way the use of it can be refuted as unnecessary. These threads are started as educational and open to discussion.

[jamesm]

Originally Posted by FA20Club.com

What I asked was have you tested that at WOT yet. As far as adjusting goes thats fine to a certain extent once you start using theother enrichment tables. Without them is what i asked you test. Suchas rom a non E85 tune with ethanol in the tank and let me know how it reacts. Because if it runs the same then a specific tune for ethanol in this car is completely unnecessary is what youre trying to say then. Correct me if im wrong. What do you feel on cam phasing, ignition and cranking on various percentages. Fuel is only a fraction of the puzzle. And ethanol content changes with temperature as well. If you install ECA in your car andmonitor it from cold start to fully warmed condition youll notice a swing of about 5%. Not granted thats not allot. But its enough at certain levels to make you go back to tweaking your cranking tables. Esspecially for those in colder areas than Florida. Im sure Bill@Delicious has setup his flex fuel tables as well with these factors in mind. Im sure Shiv has tested as much as he can with what he has. But the trend lately seems to whatever options aren't available or cant be added arent needed. Why are you coding in a boost cut. that seems to be a more important parameter at this point for all the turbo guys out there. I think that should be Delicious next thread. That way the use of it can be refuted as unnecessary. These threads are started as educational and open to discussion.

i have not tested it personally as i don't have to, i can edit my tables and correct things. i did, however, point to shiv's post where he did in fact log exactly that, and prove the point very well. long trim range d applies in open loop and will keep your afr's from leaning out (or going rich) due to ethanol content swings. i didn't say it would adjust your timing, or boost, or cams or anything else. just that variations in fuel density can be compensated for entirely by the stock ecu. again, you can check out the other thread for logged proof of this if you like, but it's unnecessary. it's how subaru ecu's have worked for a long time, and i'm sure you understand this.

of course an ethanol-specific tune is necessary, unless you like driving around with crazy trims and sub-optimal everything.

i've never argued that ethanol-content aware timing, boost, cam, etc maps aren't fantastic. i want them, i can't have them, i get it. they're great.

[FA20Club.com]

Not trying to discredit your work or others just that each side has a valid point to share. Just that one side tends to say its not needed when there is always an application that makes something a necessity. It cant be 100% for everyone.Not all my ethanol tune are flex based and run great non the less but there are those who prefer the capabilities that flex implementation provides. The GTR community waited years for Flex because at those power levels 10% swing makes a huge different in timing adjustments and ive come across it in a few cases at higher power levels. So to say something isnt necessary when you havent tested in a condition beside NA and maybe low powered FI setupsthen it cant be considered absolute on any account.

[jeebus]

Originally Posted by FA20Club.com

Not trying to discredit your work or others just that each side has a valid point to share. Just that one side tends to say its not needed when there is always an application that makes something a necessity. It cant be 100% for everyone.Not all my ethanol tune are flex based and run great non the less but there are those who prefer the capabilities that flex implementation provides. The GTR community waited years for Flex because at those power levels 10% swing makes a huge different in timing adjustments and ive come across it in a few cases at higher power levels. So to say something isnt necessary when you havent tested in a condition beside NA and maybe low powered FI setupsthen it cant be considered absolute on any account.

I don't think the other side is saying it's not necessary, just that it's not necessary for everyone.

If your goal is to run e85 in a non-FI 86, and you have control over who puts fuel in your vehicle, and you pay enough attention to datalogs, you don't need FlexFuel.

If your goal is to to run e85 in a boosted 86, and you meet the same criteria above, and don't mind running sub-optimal boost levels for the sake of safety when and if ethanol content drops, you don't need FlexFuel.

If you don't have full control over who puts fuel in, or don't feel like monitoring logs, or you want to always run the max amount of boost in an FI 86, you need FlexFuel.

[FA20Club.com]

Agreed...

[RickyB]

Originally Posted by DJCarbine

I supposed a good question to ask is if optimal cam phasing is different between E10 and E85 fuel, and if ecutek flexfuel has the ability to interpolate as it does with the fueling/ignition

This is a very interesting question.

I am currently working on the next release of the Hydra 2.70 software/firmware for the Spring 2014 release and one of the features being added is full flex fuel interpolation of intake and exhaust cam position values across pairs of 3D 32x32 target tables. I believe this is critical to the next generation of flex fuel operation because it allows engines to be built for for NA and FI with higher static compression to offset the drop in mileage associated with E85 at lower compression values. The main reason we see a mileage drop with E85 is that we have been building gasoline engines and running them on ethanol. This means that we keep the static compression low to tolerate pump gas but making them unable to squeeze the mechanical efficiency that E85 can provide at higher compression. What the next generation of flex fuel control allows is engines built with high static compression that use engine management to retard intake cam timing during gasoline operation to lower the dynamic compression of the engine (the longer you wait to close the intake valve, the lower the effective dynamic compression ratio of the engine, regardless of static compression). It makes less power and is less efficient, but still safely makes the most of what pump gas can give.

With direct injection and E85, you can run even 20-25psi at 13:1 static compression ratios and NA at 15:1 or higher. This extracts very high efficiency from ethanol. If the engine management allows, the dynamic compression and boost can be lowered to allow gasoline to be used (although with reduced peak power).

Traditional high power builds dictate that static compression be kept in the 9:1 range for built forced induction applications with fixed cams. This does not have to be the case with advanced engine management on variable cam engines. Here, you can have your cake (high peak power) and eat it (high mpg), too.

[pixel67]

Originally Posted by DeliciousTuning

I currently sell only the tune but working on my own hardware kit. This should be available in the next couple months with cool new features.



Currently EcuTeK is the only solution for FlexFuel on these vehicles. As for the temperature I have not used it from the Zietronics but there is a probe in the tank that also reads the fuel temperature that is used in the ECU.

Cheers,
William Knose

Bill, what are the tuning process differences between a flex fuel enabled vehicle vs a dual map config? Are there trade offs with either approach? I know that with a dual map set up you are essentially running through the tune process twice so one can expect extra dyno time to fine tune both maps. Does the same hold true with flex tunes? Total dyno time may also need to be considered when looking at the total cost of ownership for either approach.

Sent from my Nexus 7 using Tapatalk

[DeliciousTuning]

Originally Posted by pixel67

Bill, what are the tuning process differences between a flex fuel enabled vehicle vs a dual map config? Are there trade offs with either approach? I know that with a dual map set up you are essentially running through the tune process twice so one can expect extra dyno time to fine tune both maps. Does the same hold true with flex tunes? Total dyno time may also need to be considered when looking at the total cost of ownership for either approach.

Sent from my Nexus 7 using Tapatalk

Good question.

Our particular tuning process goes through calibrating the 91 octane tune (usually on as low of a tank of 91 as possible) and then switching to E85 for the ethanol mix. Now there is not much of a difference but with the FlexFuel kit installed you do not need to be pure E85 but can have some 91 in the mix as we can adjust for it accordingly. Though the dyno charts might be a little lower because of the 91 octane in the mix due to the lower ignition timing values.

But besides that there is not too much of a difference in the tuning time, maybe a few more minutes to review the FlexFuel setup and verify everything is working properly, but that is about it.

We usually charge for 1.5 maps (for NA or Supercharged), as most of the work was done on the 91 octane tune and switching over to E85 is not much more work. Not on turbo vehicles it is a little different story, so we usually charge for 2 full tunes on this setup.

Cheers,
William Knose