NefMoto

For a ME7.5 1.8T:

Current setup is 1000cc LOW impedance injectors, utilizing a Honda resistor box.  Tuned for 93 octane now.

Next step is to tune for E85, hence the large injector's used.

Lets discuss the methods, and ways you should/can go about tuning for E85.



1.  Tune for fuel trim to be ~-20% on 93 octane, ECU may or may not be able to adapt to E85 if you just fill the tank with it.  Use Lemmiwinks to adjust timing additive up 3-4 degrees, and theres a "rough" increase in power(only to be proven via dyno).  And a pseudo "flex fuel" setup without the alcohol sensor.

2.  Adjust fuel trims in the same way above(KRKTE, etc..) to get a legit fuel trim value, and adjust the KFZW's closer to KFZWOP, 20 percent closer in small increments and monitor CF's.  This option would be to run ONLY E85 on this tune, no ability to run 93 gasoline in a proper manner. 


Option one seems like a fair idea, Dont necessarily need to squeeze every last drop of performance out of the E85, as it does carry other benefits other than power(cooler, higher octane to prevent detonation, cleaning, etc...)

Lets discuss, any thoughts to another method?  Tuning logic?

You can't tune for 100% e85 using the ECU's adaptive channels. The adaptive channels have a range up to ~24.5%, not enough for 100% e85. You can use the adaptive channels to run a mixture of e85 and gasoline but the mixture would fluctuate and you'd have to make constant changes. I did this last fall when experimenting with e85. It gets annoying quickly but is fine if you just want to play around.

Adjusting KRKTE for 100% e85 is ideal. Run your tank almost to empty and fill up with e85, then flash a file with increased KRKTE. I guestimated it by adding .020 and then adjusted based on LTFTs. I think the end result was an increase of .027. Didn't take too long to get it dialed in. KRKTE was the only fueling change I made for e85.

Once I got fuel dialed I incremented the KFZWs in the high load columns. I started with the stock maps and added 10* to the highest load column then ramped the next highest load columns up to match. Logged and increased timing based on FATS. Go by FATS and MBT instead of knock or CFs.

The tune would be meant for e85. If you wanted to switch to 93 you'd want to flash a 93 file. If I'm ever traveling and think I won't be able to find an e85 pump I make sure I have my laptop.

how do you log FATS and/or MBT?

What is FATS?

Thanks,
Rey

FATS stands for For Advancement Of The S. It's a B5 S4 specific measurement of how long it takes to from 4200 RPM to 6500 RPM in 3rd gear. One of the ways to measure performance.

MBT is minimum timing for best torque. On gasoline a lot of guys tune their timing based off knock voltages and correction factors. e85 is much more resistant to knock so you can't tune timing based on knock voltages or CFs. So you advance timing until torque stops increasing. If I understand it correctly.

Matt, great info! thats sounds like an ideal method.  10* jump though? i know its e85 that seems to far to begin with, but thats just me being cautious.

That info will really help me out when we get on the dyno, we will be dyno tuning the thing for a few hours(already scheduled) so....sweet!  I will surely post the results we have.  This is scheduled the first week of sept. so dont expect it tomorrow

There is a certain tuner that currently has files (flexfuel) that will adapt between straight e85 and whatever octane (91-93) for the MK1 R32 engine. All that is needed are larger injectors (550's or 630's) I have to check. I believe all that's required is an idle warmup and the tune adjusts itself accordingly.

Yes, i saw this :)  Thats why i posted method 1 above, that is my assumption as to how he does this???

They might just set KRKTE in the middle and let the ECU adapt back and forth. Not sure if it'd be enough to keep it from throwing a fuel trim code.

Yea matt thats exactly the logic i had on option one, would pull a little back or add a little either what way.

Then adjust timing via lemmiwinks. and be done with it.

Gotcha. IMO having an e85 file and a 93 file is easier. Otherwise you'll be constantly having to log, check LTFTs and tweak with lemmi. Both require a laptop.

This is a scenario where having switchable maps via the cruise control stalk or something would be useful.

That, and i wouldn't trust open loop fueling ... speaking of which, do ltfts affect open loop? i forgot.

Hello,
i regularly use 100% E85 for my everyday used A4 with 150hp ANB engine.
Lemmiwinks helped me to adjust timing 8° earlier and primary fuel trim to +25%
I got issues with P1128 and P1137. So i adjusted idle speed to 850 and secondary fuel trim to 67%. Seems to work without codes at the moment. But the engine stillk feels not as powerful as with E10.

Now i search for the right locations of KRKTE, FRAUMX,FRAUMN, FRAOMX, FRAOMN, KFMIRL, KFPED, KFMIOP, KFZW and MLHFM (to compensate my much too low maf-signal) in my file to make it run perfect with E85 and safe with normal pump gas.

If it was somehow helpful for you i could post a log of some driving on german streets.

Best regards,

Buergi

P.S. i think i got all necessary toys for playing:
-friend with vcds
-cheap french E85 2km from here
-galletto 1260
-spare ECU 4b0906018AL (for safety)
-ebay USB-KKL Interface
what else is missing ?

I don't see how you could make this work well without integrating an octane sensor on the return fuel line.

Ethanol has only 50% of the energy per volume.
using E100 would mean 100% increase of injection volume for the same power.
now there's only 85% ethanol in it and you have advantages with knocking/ignition/EGT.
So what would be the volume advance you need for same power? roughly...in practice.

Good thread, I was going to make one of these eventually.

I'm personally going to do separate E85 and 91 tunes, so I bought a cheap second ECU to put the other tune on and keep in the car for when I need to switch to pump gas on the fly (I bought it to tide me over until someone figures out multiple map switching on 1 ECU).  But after that I bought a cheap Acer Aspire One netbook that I'm going to always keep in the car with flashing software and my different files.  So I'll be able to flash files whenever instead of physically swapping ECU's.

Since I've got a laptop always in the car to flash whichever file, I will likely tweak the E85 tune when the fuel changes for the first time, so then I'll have different files for E70 winter, E85 summer, and whenever else. 

I'm putting an ethanol content analyzer in my car and will likely check the content after  almost every fillup.  I was checking out the ECA from Zeitronix, but it seemed pretty expensive for just a gauge (you still had to go get the actual sensor from a junkyard.)  So what I decided to do instead is buy this small digital o-scope to keep in the glovebox, with which I can accomplish the same thing as the Zeitronix ECA (and then I can use the o-scope for other stuff that I need to when I'm not checking the eth cont :) ).  The sensors in the OEM flex fuel vehicles indicate ethanol content and fuel temperature by sending a wave with a certain frequency and pulse width.  The frequency indicates ethanol percentage, such that 50hz=0% ethanol, 150hz=100% Ethanol, and +1hz=+1% eth.  The pulse width determines fuel temp such that 1 millisecond = -40*F and 5 milliseconds = 257*F.  I'll print out calibration charts like this and keep them in the glovebox with the o-scope, to check the stats after filling up.
(http://i56.tinypic.com/20a8o06.jpg)

-Here's a list of the cars to pull the OEM sensors from (new they're $300+, so act like it's just some small sensor):
http://www.zeitronix.com/Products/ECA/ECA.shtml

-Here's the o-scope I bought (I've heard of people going with a cheap $30 DMM from Sears as well):
http://www.seeedstudio.com/depot/dso-quad-4-channel-digital-storage-oscilloscope-p-736.html

(http://i297.photobucket.com/albums/mm235/jibberjive/RS6%20Build/IMG_6825.jpg)

(http://i297.photobucket.com/albums/mm235/jibberjive/RS6%20Build/IMG_6829.jpg)


Just some insight into how much the ECU does and doesn't adapt, I used to put ~3-3.5 ga of E85 per tank together with my 91 oct, to raise the octane a little bit since I had a tune for 93oct, but only 91 gas available.  I eventually tried to add similar amounts to my stage 1+ B6 1.8t A4, but I because the last time I did it (about 3ga E85 and 16 ga total) I tripped a lean condition run code.  I didn't want to risk damaging the engine, but the ECU can definitely only adapt so much.


So you don't worry about being knock limited at all when tuning with E85, eh?  Knock and CF's are still good indicators to make sure the tune is safe though, right? (E85 doesn't affect the knock sensors ability to detect actual knock or anything like that, right?) I'm new-ish to MBT tuning as well, but is MBT boost independent then?

Say one was knock limited on a pump gas tune, then goes E85.  Turns up the injectors and finds MBT. Checks knock/CF's and they're still in check.  Assuming the turbos still have some efficiency to go, then would you up the boost (while keeping lambda in check) until it's knock limited again (assuming that the knock limit comes before the turbo leaves its efficiency range)?

I've read of guys doing this because the ethanol content varies between stations and deliveries. I haven't kept track of the ethanol content at the local pumps but I try to stick to 1 station that's nearby my house. So far I haven't experienced any oddities related to ethanol content fluctuation.

Quick Fuel makes a $15 e85 measurement tube, I'll probably grab one to satisfy my curiosity.

(http://www.quickfueltechnology.com/specialty-parts/images/36-e85eChecker2.jpg)

http://www.quickfueltechnology.com/specialty-parts/echecker---e85-fuel-test-tube.html


I'm still learning but in my limited experience I have not been knock limited with e85. It's very resistent to knock and so knock volts and CFs are misleading.

A lot of people tune timing based on knock and CF, including guys on regular gasoline. This is useful for people who don't have a dyno or some controlled environment to measure performance. My understanding is that the correct way to tune ignition timing is to advance until max torque is achieved or when knock occurs (then back down a little). I've been told "e85 won't knock" and in my experience this has been true.

On gasoline tuning ignition timing based on knock and CFs is fine if you don't have the luxury of a dyno. On e85 you won't get accurate feedback of the car's performance from knock volts.

I've been using the same stretch of road and monitoring my FATS. My timing logs:

(http://mattdanger.net/s4/logs/e85-v15/image008.png)
(http://mattdanger.net/s4/logs/e85-v15/image009.png)
(http://mattdanger.net/s4/logs/e85-v15/image010.png)

So again, my answer is don't advance timing based on knock with e85. Advance until you stop making power.

Matt: a bit off topic, but have you ever figured out why the timing oscillates so badly between two very distinct operating points? I've seen this in many, many tunes.

It seems related to the rate of increase of MAF and/or RPM.

I honestly believe it's related to 2 things...

how clean your MAF signal/curve is.. and knock volts...

The quieter/cleaner both are the less timing drift you will see... that's what I've noticed so far.

Matt, how do you tune for MBT without the use of an emulator?

No :( I have searched and read threads (yours and others) on the topic but am unsure of the cause.


Poor man's method: Log FATS times on the same stretch of road under similar conditions and increment from there. I have been doing it little by little and am uneasy about making more advances because of my inexperience.

SIGH. We need to put this on the short list of things to solve. I'm sure its hidden away in the Funktionsrahmen somewhere.


Heh. This is why I added HP/TQ estimation to ECUxPlot :)

Also, gtech (or similar accelerometer) isn't a bad way to do this kind of tuning. A much bigger problem is how fast you are going at the top of 3rd .... on a public road?

what do you mean exactly with oscillating timing?
the frequent plots on 20 as either 25 degrees in the first diagram?
wouldn't it be more precise to see it with a correct time axis?

Yup


They look almost exactly the same :) Boy, I wish I knew the cause.

can you post a WOT log with it instead of an Excel x-y map?

Here's one. Very old. No clue what tune its from.

The oscillating timing might also be a torque intervention through ignition angle out of torque coordination.   
I haven't looked at the calibration and usually you don't allow this on full load, but with all the scaling and stuff you never know.
If anyone wants to dig a bit deeper I would recommend to have a look at MDKOG and MDZW.

Forgot something  ;D

Log zwist and zwbas. If zwist<zwbas you get a torque intervention through ignition angle.  ;)

good to see you back on here Silentbob...

Question that I've always had... Is it worth it to rework the Optimal TQ map in the ECU to closer represent what the motor is really making?

looks quite odd.

when WOT: actual boost is WAY far away from desired.
Lambda desired goes till 0.67.
Any actual lambda or WG DC?

I would say the engine is deep in BTS and not running healthy at all.
I saw similar durametric logs with fuel problems where the differential pressure tube was removed from the FPR.

Its intentional. Its the only way to get very rich fueling (that I know of) on 91 oct through req AFR.

If there is a better way to get .6-.7 lambda from peak torque through redline, let me know :)

Not sure that is in ECUx.. if so, what are the names?

If not, is it loggable in setzi's ME7L?

And how to fix it? MDKOG is a single bit, and I can't seem to find MDZW anywhere

Any of these?

http://s4wiki.com/wiki/Tuning#Torque_limits

Don't know about ECUx but it's in setzi's logger.
MDKOG and MDZW are sections in the Funktionsrahmen  ;)
General overview of the torque structure is in section MSF.

Not excatly sure what you mean. KFMIOP should be the inverse of KFMIRL!?

I thought that KFMIOP was supposed to represent the "fuellung" or VE of the motor, I was wondering when doing other changes (turbos, cams, etc) if one should try to adjust KFMIOP at all?

What do you mean that KFMIOP should be the inverse of KFMIRL?

It's not that simple.
That is getting a bit too off topic.
If I have some time I will do a write up about the basic torque structure and post it in a new thread.

Gracias... yes sorry for going OT :)

Yea, partially my fault as well for dragging it in this direction. Thanks in advance Bob. In the meantime, I will review the FR :)

no, doing rich fuelling with BTS is absolutely ok,

but 0.6 -0.7 is desired from the tune with only 1 bar boost? that sound very odd to me, and may be also for the ME7 ;)

ok. maybe I was exaggerating. Call it .7-.8.

You just dont understand how bad 91oct is at 1.5 bar :)

but that loging never reached 1,5bar, but seems to demand it...

do you mean 91 oct ROZ, MOZ or US?

US

that is EURO Super = 95 ROZ/RON, not too bad.

No, its far worse because the base fuel is garbage (generally 87), and they get it to 91oct by adding ethanol in CA.

Yup, I don't know what it is in Cali, but in Utah our gas is up to 10% ethanol as is (and the most we can get is 91 oct as well, and we're at altitude ha).

same in europe: they sell it as E10 with 95 RON specs for the same price.
But you need to know that 95 RON has also up to 5% ethanol inside for some years.

in case of trouble you can get 98 and 102 RON everywhere, but I do not expect the car will run any richer with the 95 fuel.

The stoich for the fuels are quite different. A E5 95ROZ is ~14,3:1, a E10 more ~ 14,0:1 whereas a typical 98ROZ ~14,6:1.
This is all data from fuel analysis in a lab.

I live in Brasil and we deal with E100 since the 70´s...

We have ME7.5.20 and 7.5.30 here wich are OEM flex fuel (E100~E20) as they are very diferent from the ME7 used in 1.8T and other we can´t tell how it works with sure, but i has +/-25% correction from the base fuel map, if the ECU states the fuel is E100 the adaptative can reach +/- 25% before a MIL code, if states E20 the same occurs.   If it´s not just a KRKTE adjustament... in theory you can adjust KRKTE to be in the middle (in you case E85~E10) but it will have some issues in the warming or starting in some temperature/fuel.

PS: these ME7 states the mixture only by the lambda probe, some has only 2 narrow band sensors, and some have a Wideband sensor, the strategy is made when you refill with more than 20 liters, engine is off for more than a certain time, and other triggers.


To simple convert to E85 you can start adding about 5~6° ... here with E100 We start with 7~8°... in some condition/engines I add even more than 10°.

I love e85.  just got logs back from my first e85 base file b5 s4 stg 3... 0.2 sec faster FATS off the 93 octane file.  This shit is gross!  ;D

Is KFZWOP suppose to = MBT ?

Yes

Edit: Ähh sorry wrong. KFZWOP is usually the ignition angle with 50% heat release at 8° ATDC on lambda 1. It can be MBT if not knock limited.

Ah. so because E85 has a different burn rate than gas... stock (gas) KFZWOP <> MBT (or 50% heat @ 8* ATDC) on E85.

So how do we update KFZWOP for E85 to make it as MBT reference? I mean do we increase it by some percentage or decrease it?

For A95 it would be easy to use KFZWOP as reference (copy values from it to KFZW and then decrease whole table by few percents and then decrease even further in low rpm area)...

You can do it that way, then ignition and fuel is working:

Injection:
-krkte in the middle of e85/e100 and the lowest e-possibility (in some countries 0, in other up to 20)
-typically the difference of e85 to e5/e10 (european fuel) is around 28%, so your lambda adaption window with 28%/2 will be enough with +-25%, that way you will find very fast a not working maf and lambda ;). But if you were using E0...E100 you will have to widen the allowed adaption value to around +-30%, as the difference is already around 40%, and if you drive in different atmospheric pressure it could be that it is not enough with +-25%
- raise the adaption-speed per injection and ignition, that way you will have after about 1mile driving already the adapted fuel
- for a good cold start in low temperatures, you will have to raise the enrichment up to 10degrees with around 500%. The warm-up cycle will be ok with around 30% raised. Also you can let the throttle a little bit more open in starting (around 5-8degrees) up to 400rpm. That will prevent overfueling in starting with gas


Ignition:
- Setup the highest allowed retarding to around 7.5degrees, that way it will jump automatically in another ingition table. You can setup than one for your E85/E100 and one for your gas, as the difference is very huge. Also you can setup the speed of reaction for that action
- Starting angle should be raised at temperatures below 10degrees celcius around 8degrees
- The optimum Ignition angle should be raised on most of the ecus available, as you can drive with e85 in most cases higher than the oem-values for gas. Remember also to raise the small maps for the driver requested ignition, as otherwise it will go to a very late ignition when you drive normal

Doing it that way you can mix it up.

The disadvantages are:
- you will drive much too rich for e85 on engines that do not have an egt-sensor, in protection mode you will never need that high enrichment like with gas, as you cool already around 20% down with e85 compared to gas
- when you drive with pure gas, you will have to wait some seconds before the correct ingnition table is used as it will first have to realize the knocking
- to be more safely you will have to setup a lot of safety-functions (reducing load by knocking etc.)

Thank you for this awesome reply :) Now KRTKE I've sorted out by adding about 30% (in the end o2 sensor fixes everything :)). Now which map is responsible for adaptation speed per injection and ignition? 


Also I really need all these maps IDs... :) Will have to find them and define them in my own map pack... too bad there are no damos files for my ecu...

Sweet!

The speed is set up by rkatmn/mx - rkatrn/rx and rkazmn/mx - rkazrn/rx, TVLRA



You will neet FKSTT and KFZWSTTM for the start. On some you can adjust the opening level, but on some ME7.5 this is not present.

Thank you again, you are very helpful :) Now I've found these maps rkatmn/mx - rkatrn/rx and rkazmn/mx - rkazrn/rx, TVLRA, but they look like they're threshold for adaptation (except for TVLRA, which is time for adaptation or something - in my file it is 2 seconds) and they're in %. So should I just make for example rkatrn -30% and rkatrx +30% ? And in TVLRA should I just lower it to 1 second? Maybe you remember ID of throttle plate angle on cold start (or other map with which I could open throttle plate a lil bit wider on cold start)?

Also I've found two enrichment maps FKSTT_1_A and FKSTT_0_A, so I've changed them both. Maybe you know why there are two maps instead of one?

And finally what do you think, will these be sufficient? (image attached)

You adjust with them the general speed of adaption. So if you took wider values it will work faster, but takes of course some ecu-power.
When you set up TVLRA it will faster/slower add the values to the long time adaption (see chanel 32). As you are changing the speed of adaption already, you can adjust that also. Normaly here is a value inside which prevents after accel/decel to have too big values inside. And of course it also depends on the hardware you use. That is finetuning which in the development is done for example by an extra person only doing that all day long.

QUESTION: Should I advance ignition or leave as it is during coldstart on E85? map id: KFZWSTTM
Right now my cold starts are very rough and car dies during first few attempts to start (engine starts for a second and then just dies, then I have to start the engine again. The fourth time I start engine it's rpm holds normally)

PS:> My current enrichment and ignition angle

Good info

cold start with e85 gave me hell too!  I never got it proper :(

Maybe we can look into some of those "flex fuel" GM's and see in comparison to their gas maps what they use for the alcohol mix maps.  try a percentage of change to start?

however i have no leads on e85 GM maps at this time, but someone else may?

Hm... there has to be someone on this forum who has done proper E85 conversion... :)

Yes, you need to remember that in cold start conditions, the engine ignites basically only the petrol part of the E85 mix, i.e. the ethanol is just flushed through the engine unburned. This means that the enrichment for cold start is massive and that you can expect ethanol dripping out of the exhaut.

I've done the conversion a few times as E85 is very common in Sweden, and heavy (I mean really heavy) enrichment is the only way to do it for cold conditions. Once the combustion chamber increases in temperature you can decrease the initial heavy enrichment as also the ethaniol will vaporize, not just the petrol.

Can you tell me by how much should I enrich the AF mixture at 0C temperature (approximately)? Because up to the about 10-15C it is all good, but lower than that and hard start again awaits me...

My S4 runs 100% E85 seamlessly since 2 years now.
Here, E85 is 15% unleaded/85% alcohol in summer and up to 27% unleaded/73% alcohol in winter.

On S4, there's a simple/cheap way of running E85, just set fuel trim to +25% in lemmiwinks, and the ECU will do the rest of the correction !! I usually get +3-6% on partial adaptation, and 0-2% on idling adaptation.
That makes an overall correction of +28-31% max ...
No engine startup problem at all in winter, no idling trouble.

And add some timing if you want  (you are not obliged), +7.5° in my case as I already have a MRC tune. Usually from +3° to +18° (yes I tried it in winter) !!!
I notice nothing special above +10.5° except a strange phenomena: sometimes (when flooring the throttle) the timing is pulled to a default value of +12°, not nice.
So +7.5° is fine in my case.

(https://lh5.googleusercontent.com/-_R7cx3qNYnM/TxakoqmczcI/AAAAAAAAAeQ/FV-5F2arIsM/s640/%25252B18%2525C2%2525B0%252520timing%252520trim.JPG)

(https://lh3.googleusercontent.com/-wX9cSRzPqm4/TxalkcdngiI/AAAAAAAAAek/_C46EQSg4kY/s640/%25252B15%2525C2%2525B0%252520timing%252520trim.JPG)

My car pulls more than 350rwhp.
My MAF shows more than 326g/s on full boost (~1.3bar, 1.5 max)

That's my cheap way of running 100% E85.

That's just a starting point ;) I've used Unisettings to adjust my fuel last autumn, but since then moved to real mapping. Now my idle maps are OK when warm. All I need is to adjust COLD START ENRICHMENT factors and that's it.

Strange, I didn't need some many tweaks for my S4. Maybe because my S4 is already MRC tuned ...
It was even a surprise for me to have a so perfect behaviour on E85 with only Unisettings trimming.

On the other hand, my 300zx required more work to run 100% E85:
_cold/warm start enrichment tables
_cold timing
_overall advance accross the rpm/load ranges
_small adjustments in all the corners
Cold startup in winter has been a nightmare to get it right (I mean: 1-2 seconds key turn ==> immediate startup)

I see you run quite rich already so that shouldn't be the issue. I usually see a need for about 3x crank enrichment @ 0°C ambient but it needs to be decreased gradually as the combustion chamber warms up quite rapidly. Keep in mind though that the after start enrichment is different for E85 than for regular petrol and that it's not linear.

Also, you should not confuse cold engine enrichment (choke) with cold start enrichment as they are two separate things running in parallell.

Hi,

all talkes about 6-8 dec on using e85 in what of RPM or LOad you mean it? At time i have only on full Load and High RMP change about 7dec with good result :) But how i can reedjust my Ignition Timings on idle and low load for perfect economy???

Leo

Raise ignition at constant drive till load won't lower. :)
In winter you only get E70 at the fuel station because of cold start.
GM flex sensor isn't very durable.
From E100 cars I know that they start on gasoline (small extra tank for this) because ethanol won't evaporate very well at low temps.

I´m from Brasil and we have E100 here since 70´s

You can easily start the engine if the temperature is above only 17°C (E100 didn´t vaporize lower than this, so it will be based on mechanical efect os the injectors to vaporize it) will just some tweaks in temperature correction maps to keep the engine runing in Warming withou problens

 you can start the engine until about 7~8°C is you increase the fuel pressure (about 3,8Bar is what I saw in most brasilian flexfuel cars) and increase a lot the enrich based on IAT and TMOT.

Lower than 7°C is the problem...  for these I recomend use 10% gasoline in the blend


There is no easy way to make "flex" convertions... you may want to use 2 prograns, one with E85 (or E100) and another for gasoline... keep in mind that using E85/E100 will require a lot more of DC in the injectros, and they can reach 100% easily if they are not  big enough

I've hard 2/3 points for E85 conversion:
-The injection angle might need to be adjusted.
-The ethanol is not vaporing "lineary" in temperature, so, when the engine get 80° the oil vapor recycling may devy the compensation in excess.
-The wall weeting maps has to be corrected (don't ask to me how, not tryed yet).

Sorry for my english, I'm french.

Hi,

Did you tried in low load to add or remove some ignition advance ?

I know old thread but wanted to ask about best way to tune for E85 with  a 1.8t using an  M5.9.2 ECU.

I want to run 50-50 blend of E85 and regular.  Fuel trims can compensate fine but I worry about running lean at WOT so I would like to alter the basic fueling setup.  What should work best?  adding ~15%  (30% if running straight E85)  across the KFLF map or altering FGATO from 1 to 1.15.  Not sure I fully understand how the FGATO constant works  but seems like it is a correction factor applied to the KFLF map, please correct me if this is wrong.  Sounds like both methods would do essentially the same thing.

Thanks for whatever advice you wish to share.

Well, tried both methods for a little bit.  Adding 15%to kflf seems to work ok.  Fuel trims looked good  at less than 5% and it leaned up to AFR high 11s at WOT. Had max 3 knock CF.

  Did also try FGATO up from 1 to 1.15. Idle FT was 3% and adaptive FT was zero.  Not sure if this is too good to be true.   Logs show the part throttle FT briefly going to 0.8% for a bit then returning and staying 0%. AFRs looked reasonable on the gauge but did not try WOT nor logging AFRs.  Need more info about FAGTO to understand better what it does before I trust this method.

Hey,

I'm playing with ethanol, without a sensor and it almost works already, but "ltft" (fra_w adaptation, partial throttle) is really, really slow to adapt.

I have mainly touched the values ​​of FRAOMX, FRAORX, FRAODX, QUFRMX, FRMAX etc. so that I am not limited to +25%, but increased it to +34% at the beginning. Works good.

 could someone tell me how to make longfueltrim / fra_w fast responsive. It doesn't make sense that it comes back to life only after 20 minutes of driving and it seems to happen in a completely random situation. Before that, it's just a straight line. fr_w runs normally at the same time. How to make it work quickly, and live often or continuously (however, not too quickly)? At the moment, the functionality is good if I switch off the frao and frau completely with nolra, and I don't change the fuel (krkte must be according to the fuel then) Now a super slow response of fra_w ruins the system.

My settings:
TVLRA 2 (second)
ZKFRAU 0.05%/sec <-already doubled from oem, can someone explain what does this do? I see in logs about 0.2% per second increases but problem is that its loooooong flat line before it moves.

What exactly are the limits ...MN/...MX/...RN/...RX that appear in these settings? (for frao,frau,rkat,rkaz), minimun, maximum and then again same for what? It has an upper and a lower, and both for the second time, why? What is the difference between the second pair? What determines in which situation one is used, etc.?