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Author Topic: E85 Tuning Methods  (Read 78781 times)
silentbob
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« Reply #45 on: August 09, 2011, 03:44:56 AM »

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.
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overspeed
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« Reply #46 on: August 09, 2011, 03:24:06 PM »

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°.

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judeisnotobscure
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« Reply #47 on: August 22, 2011, 08:14:10 PM »

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!  Grin
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I have a b5 s4
but i just want to dance.
elRey
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« Reply #48 on: August 23, 2011, 11:08:30 AM »

Is KFZWOP suppose to = MBT ?
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silentbob
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« Reply #49 on: August 23, 2011, 11:20:16 AM »

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.
« Last Edit: August 23, 2011, 11:28:51 AM by silentbob » Logged
elRey
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« Reply #50 on: August 23, 2011, 01:16:17 PM »

Ah. so because E85 has a different burn rate than gas... stock (gas) KFZWOP <> MBT (or 50% heat @ 8* ATDC) on E85.
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masterj
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« Reply #51 on: November 30, 2011, 03:42:20 AM »

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)...
« Last Edit: November 30, 2011, 03:45:39 AM by masterj » Logged

stack
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« Reply #52 on: December 03, 2011, 04:29:33 AM »

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 Wink. 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.)

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masterj
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« Reply #53 on: December 03, 2011, 06:03:50 AM »

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

Quote
- 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

Also I really need all these maps IDs... Smiley Will have to find them and define them in my own map pack... too bad there are no damos files for my ecu...
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jibberjive
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« Reply #54 on: December 03, 2011, 09:06:49 AM »

Sweet!
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stack
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« Reply #55 on: December 03, 2011, 12:09:41 PM »


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

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


Quote
- 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

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

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.
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masterj
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« Reply #56 on: December 06, 2011, 02:50:07 PM »


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

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


Quote
- 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

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

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 Smiley 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)
« Last Edit: December 06, 2011, 04:40:23 PM by masterj » Logged

stack
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« Reply #57 on: December 10, 2011, 03:23:05 AM »

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.
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masterj
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« Reply #58 on: January 16, 2012, 02:56:13 PM »

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
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RaraK
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« Reply #59 on: January 16, 2012, 06:05:54 PM »

Good info

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

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?
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