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Author Topic: e85 kfzw tuning for 1.8t DBC, equivalent KFZWOP, need some advice  (Read 22602 times)
Jason
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« Reply #15 on: May 03, 2016, 06:52:53 PM »

which means, of course that the ECU will calculate ignition efficiency wrong, so ideally, you do want to set KFZWOP correctly.

Personally I feel as if you shouldn't touch KFZWOP unless you are instrumented for cylinder pressure and combustion efficiency.  If somebody is making changes to KFZWOP, I'd like to know where they are getting the data from, aside from pulling it out of their ass.
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nyet
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« Reply #16 on: May 03, 2016, 10:07:44 PM »

Personally I feel as if you shouldn't touch KFZWOP unless you are instrumented for cylinder pressure and combustion efficiency.  If somebody is making changes to KFZWOP, I'd like to know where they are getting the data from, aside from pulling it out of their ass.

Definitely don't disagree.
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Jim_Coupe
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« Reply #17 on: May 04, 2016, 01:40:11 AM »

Jason, Always nice to read info on E85 since I now run all my 3 audis on E85 now..  But i have never bothered to look into my ign tables until now.  I will start experimenting on my Me7.5 1.8T. I had a feeling that it works as you described in your post.  "ign detonation will work against it self"..  I have now added 2 -3 degress all over the table and I will add more in some red areas and se what result i get..

One more Q"..  KFZW = High octane?  KFZW2 = Low Octane?
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E85oholic
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« Reply #18 on: May 04, 2016, 04:04:20 AM »

What do you mean by that last sentence?
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adam-
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« Reply #19 on: May 04, 2016, 04:33:40 AM »

One more Q"..  KFZW = High octane?  KFZW2 = Low Octane?

No cam advance, with cam advance.
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eliotroyano
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« Reply #20 on: May 04, 2016, 06:21:46 AM »

I always ask myself the reason of KFZW & KFZW2 (cam timing variation) if DBC engines does not have it. Then really does cam advance controls it?
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k0mpresd
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« Reply #21 on: May 04, 2016, 06:44:41 AM »

early 512kb me7 engines do not have VVT either.
4B0906018P for example. kfzw/2 are verbatim though as well.
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overspeed
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« Reply #22 on: May 04, 2016, 07:35:23 AM »

I make about 5 cars for week in E100, we have this on pump in Brazil since 70´s

talking about E100 ( E85 is not avalible here in pump)

1- you´ll end with more advance than KFZWOP if you want maximum power

2- Agree that you can´tell real KZWOP values without factory instruments, BUT you have to decide:

If you run lower advance than KFZWOP you are not going deep in tuning (there is some load x RPM that KFZWOP are only 1,5° above KZFW)

If you raise KFZW higher than KFZWOP you may have some issues with ignition efficiency calculation

So, the only remaining thing to do is raise KFZWOP... even don´t knowing the "real" value.

what I do is raise KFZWOP, tune KFZW in dinamometer, after it´s done I make KFZWOP about 1,5 to 2° higher than KFZW... don´t know if it´s the rigth thing to do, but it´s the only way I found.

EGT will change with advance modifications, so it can be used to help find KFZW values, but on dinamometer is much more quick to make it... and believe, in some conditions even E85 can melt pistons... just run more than 0,88 lambda some time and it will happen
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Jason
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« Reply #23 on: May 04, 2016, 08:15:10 AM »

KFZWOP will definitely need to be changed to make max power.  No doubt about that.  There is a lot of power on the table.

The problem is MBT is a moving target across the load and RPM ranges.

I think it's virtually impossible to hit all of those conditions on a dyno, AND measure the rise and fall of torque as you reach MBT and then pass MBT.  You can probably get close, but it's a balancing act, and I don't think I'd personally rely on that.

You can also hurt the engine or your fuel efficiency by scaling KFZWOP past MBT at lower loads, something that is difficult to measure on a dyno.

On the subject of knock resistance and what you can get away with, I've been doing a lot of E85 research and testing lately on my beater Allroad, (testing before I convert my S4) and I am amazed you can get away with 225+ degree IAT's when you ride the upper limit of KFZWOP.

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overspeed
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« Reply #24 on: May 04, 2016, 09:16:41 AM »

Thats what i'm saying... There is no easy copy solution, and demand a lot of logging and test...

You can put easily 9° advance with E100 and not bad will happen, except you past mbt and will end with lower torque values...
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nyet
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« Reply #25 on: May 04, 2016, 11:37:59 AM »

If I had to make a half assed attempt at guessing at KFZWOP values, I'd start by simply altering the areas where you think you'll make more timing than the stock KFZWOP, and minimally set those to your max expected timing.
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Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
k0mpresd
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« Reply #26 on: May 04, 2016, 11:49:10 AM »

my seadoo file actually has OP less than KFZW in parts of the map. never quite understood that one.
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Jim_Coupe
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« Reply #27 on: May 04, 2016, 03:14:13 PM »

Anyway i tested my ign version 4 today.. feels good but im not ready to decide yet.. I Measured 622C EGT directly after turbo.. Shall i add 100 degress on that to get more close? I added most timing in low areas.. dunno if i want to go more in high rpm and load areas.

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E85oholic
Jason
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« Reply #28 on: May 05, 2016, 12:04:35 AM »

While we are on the subject of E85, has anyone else noticed that switching to E85 from pumpgas results in crankcase pressure dropping significantly?

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NOTORIOUS VR
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« Reply #29 on: May 05, 2016, 01:20:57 PM »

Tuning by feeling never works regardless of the fuel. 

IF you don't have access to a dyno, you should be comparing acceleration #'s to confirm if the car is going faster as a quasi "road dyno"

It's very easy to over-advance on Ethanol.  Tuning it using knock sensors is completely pointless.
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