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Author Topic: e85 kfzw tuning for 1.8t DBC, equivalent KFZWOP, need some advice  (Read 22597 times)
Placebo
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Been trying to figure out best timing for running e85  and read somewhere here that kfzw should be set close to kfzwop for me7.  Problem for me is I don't think I know kfzwop for my m5.92 AEB.


I am thinking I should estimate based upon ME7 files what the equivalent KFZWOP timing values would be for my AEB and tune to approach these values, bad idea?
This is shown below. I don't really know how the ms loads for my maps correspond to the %loads in the me7 maps but I figured they probably represent the same info for scaling purposes.

If anyone has a good kfzw map for 100% e85 on an AEB would very much appreciate seeing the values.  Im all stock except for DV and big injectors.

Thanks for whatever info and advice you can share.
« Last Edit: May 02, 2016, 11:38:49 AM by Placebo » Logged
Jim_Coupe
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« Reply #1 on: May 03, 2016, 12:54:40 AM »

Im running Me7.5 an I started adding around 2 degrees over the entire map.. Then i raised them slowly bit by bit at the same time I measured my EGT´s very very close.. (Also log your inition so that you know that youre on target) I also started off by running very rich around Lambda 0.75 at higher loads and slowly decreased the lambda until EGTs went up. I have never managed to get knock ever on E85. Its a bit scary. (E85 is not so sensitive to run rinch, but check you injector duty cycles so they dont get stuck.). Im not sure if this is the proper method though.. Im still looking for a godd method to tune E85 without a dyno..
« Last Edit: May 03, 2016, 12:58:37 AM by Jim_Coupe » Logged

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« Reply #2 on: May 03, 2016, 05:35:35 AM »

Thanks for info,  did you always increase the timing over the entire map?  Did your lambada change much from a 93 tune?

Part I'm really struggling with is how the kfzwop values are so skewed from kfzw base values, not  just more advanced. 

I'm interested in the kfzwop values because I think they represent MBT and something close to what e85 timing should be.  Can someone confirm this for me?

I can start off slowly bumping up timing but I'm gonna struggle knowing if I've added too much without a billion logs of rpm. timing and load.  I'm scouring the inter web to find a dyno tuned kfzw map for e85 I can use as a guide.




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Jim_Coupe
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« Reply #3 on: May 03, 2016, 07:10:03 AM »

Im running this now in my Me7.5... But today I added 2 degress more over entire map just to se what happens Smiley Didnt logg or anything.. It ran slightly better i must say.. i could be placebo but. Im going to add some more timgin in low load areas...  I just have to fix my immo problem in the other thread... I have managed to lock my ECUs Sad
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« Reply #4 on: May 03, 2016, 08:32:28 AM »

With E100 you can go next to 9° plus advance in high load/RPM ... in mid range 6°...in low load /RPM areas somethig between 3 and 6° works great...

KFZWOP is optimal for gasoline, Ethanol burn slower and shall have more advance to work good... you can use it as a start point, but at end will notice values greater than KFZWOP work better... something like 3° plus entire range at least.

Dont´forget to raise KFZWOP to not fall at engine torque monitor issues...
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Jim_Coupe
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« Reply #5 on: May 03, 2016, 09:07:10 AM »

KFZWOP you said something there..  I have to take a look att that

When is KFZW and KFZW2 used?  and when do we see when we are close to melting the pistons? E85 dont knock! Are you using an EGT gauge?

Hope i dont steal the thread here Smiley
« Last Edit: May 03, 2016, 09:08:59 AM by Jim_Coupe » Logged

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« Reply #6 on: May 03, 2016, 09:11:23 AM »

Thanks for the info, both of you.  I guess I will start with setting my KFZW a few% lower than my inferred KFZWOP AEB map and try to get my timing close to Jims in the load areas and then begin the logging and tweaking.
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nyet
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« Reply #7 on: May 03, 2016, 10:34:53 AM »

KFZWOP is NEVER directly used for actual timing. It is a reference to calculate ignition efficiency.
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« Reply #8 on: May 03, 2016, 10:38:28 AM »

KFZWOP is NEVER directly used for actual timing. It is a reference to calculate ignition efficiency.

Thanks for clarify that !
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« Reply #9 on: May 03, 2016, 10:45:04 AM »

KFZWOP is NEVER directly used for actual timing. It is a reference to calculate ignition efficiency.

I was assuming based upon what I read that it was good guide for running e85 when not knock limited. I don't really know enough to argue so ill keep reading until I figure it out.  Thanks.
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« Reply #10 on: May 03, 2016, 11:53:35 AM »

There is no need touching OP at all. You can ad about 3-6 deg on E85 allover the range
One thing here is really importen and it is you do not need to log EGTs or knock. It is pointless n wrong when tuning E85
What you need to do is
Start at oem timing values. Ad 2 deg and LOG!!!
Ad 2 deg again and LOG!!
As long it is making Torque and is faster - ad timing. When it start making less TQ at timing raise - you are done.
Dont get gready here. Take it easy and know your Ethanol content.
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Jim_Coupe
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« Reply #11 on: May 03, 2016, 01:06:51 PM »

thanks for that info Mocke.. But can you log knock? Is there any?

I just came in from a test run and I added now 3 degrees on stock timing in low areas.. I got the feeling that it was a bit more alive. Im look into the 2000 rpm+ range now and se what happens... I dont have the EGT gauge installed but will try to install one..
« Last Edit: May 03, 2016, 01:09:10 PM by Jim_Coupe » Logged

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« Reply #12 on: May 03, 2016, 01:41:27 PM »

KFZWOP you said something there..  I have to take a look att that

When is KFZW and KFZW2 used?  and when do we see when we are close to melting the pistons? E85 dont knock! Are you using an EGT gauge?

Hope i dont steal the thread here Smiley

KFZW and KFZW2 are used cam (VVT) position

E85 will give you much lower temperature than gasoline... and is related more with lambda values (BTS stuff), point is the higher EGT will give you the best torque mantaining lambda at same value.

For example, Up TSi (MED17.5.21) here in Brasil uses E100 and even in BTS never goes down lower than 0,95 lambda (when running E100, witg gasoline it´s something close to 0,75 lambda)...even in high load, RPM and prolongued time as it never reach temperature to mel anything...


Log EGT to achieve best troque values - OR as said by mocke just start raising advance till get best torque values... Keep lambda at a secure point and after found the "best" advance you may want to deal with lambda and see what happens...

KFZWOP is never used to timing as said by nyet, it´s a theorical value for optimal advance (FOR GASOLINE) if not knock limited...   E85 timing will ALLWAYS be higher than this...
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« Reply #13 on: May 03, 2016, 03:31:19 PM »

KFZWOP is never used to timing as said by nyet, it´s a theorical value for optimal advance (FOR GASOLINE) if not knock limited...   E85 timing will ALLWAYS be higher than this...

which means, of course that the ECU will calculate ignition efficiency wrong, so ideally, you do want to set KFZWOP correctly.
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« Reply #14 on: May 03, 2016, 06:46:37 PM »

It seems to me there is some confusion here about how E85 works.

E85 (measured 85% ethanol content, to be specific) is extremely knock resistant.  EGT doesn't mean anything when tuning E85, either.  EGT does not indicate how close you are to MBT.

With E85 your goal is to move your ignition advance towards MBT (maximum brake torque), but not mechanically damage the engine with an ignition event that occurs BEFORE top dead center.   As soon as you advance past MBT, torque output declines because that energy is wasted on slowing a rising piston that has not yet hit top dead center.   The engine fights itself.

That is how you break hard parts with E85 - combustion before the piston reaches top dead center.  The difference between gasoline and E85 is damaging combustion events won't happen on their own with E85 because it simply does not combust on its own.  YOU will cause the damaging ignition event by pushing your timing advance past MBT, causing the ignition event to occur before top dead center.  It won't get too hot, ping, and then turn inside out.

You will not be able to properly tune E85 for maximum power without instrumentation for combustion analysis and measuring cylinder pressures.  Anyone who tells you otherwise does not understand how E85 works.
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