correct KHFM-Calculation @ M3.83 /M3.8x?
eliotroyano:
Quote from: MIL_on on March 26, 2014, 01:29:55 PM
Btw here is the document, where i found the base of my initial guess:
http://www.google.com/patents/DE4336813A1?cl=de
That is good technical document, that I need to read in detail. Thanks for it.
Quote from: MIL_on on March 26, 2014, 01:29:55 PM
so i agree with you in all points except one:
I think that this Ki you are using in your first formula is KHFM for real. But it is only used for building the main load signal and being tweaked via the factors to become the correct value for the non-ideal but real engine injection time including external influences.
Sorry if I don't elaborate more my idea about Ki (KHFM) in Tl (Load) = Q / (n * Ki) formula. I agree with you, Tl (Load) here is the main Load calculation, known as Specified Load --> http://s4wiki.com/wiki/Load
Quote from: MIL_on on March 26, 2014, 01:29:55 PM
Prj also pointed me into a important direction (thanks for that mate!) :
By changing KHFM all maps using load on one of their axes will be screwed up! So its like natural underscaling by using another injector in my equation above...which makes me unsure whether it can be correct, because i can only hardly imagine that bosch built such a crappy ecu, where every map has to be redone when changing the injectors!?!
My understanding is that KHFM, as a constant, defines the main play zone (load area) where engine should work (from max vacuum to max allowed boost) not defined axis. That means that from "X1" load takes "Y1" value in other map or maps, but if we change KHFM, a different load value, "X2" for example will take "Y2" result. This work if for all maps if the X & Y values remains under the maps axis size, if not we don't have other way than scale related maps by hand. That is my idea.
Quote from: MIL_on on March 26, 2014, 01:29:55 PM
also you mentioned your khfm is 8 bit? But in the damos its 16 bit?
I mention that my 1.8T AGU 06A906018CG KHFM value is 84 @ 8bit Factor 1 Offset 0, but is totally right value 43860 @ 16bit LoHi Factor 1 Offset 0.
Quote from: MIL_on on March 26, 2014, 01:29:55 PM
The next important question for me is: what are the 3 different kfzw for?
From my research in M38x & M592 I found this info:
-KFZW - Zündwinkelkennfeld: Main Ignition Advance Angle Map (pre-calculation map) --> X/Y/Z : Load (ms/RPM) / RPM / Crank Angle BTDC ºDegrees.
-KFZWNA - Zündwinkelkorrekturkennfeld: Ignition Correction Map by Coolant Temperature (ECT) --> X/Y/Z : Coolant Temperature (°C) / RPM / Crank Angle BTDC ºDegrees
-KFZWOPT – optimaler Zündwinkel: KFZWOPT = Optimum ignition angle at lambda = 1 / Ignition Firing Angle Optimum Map - Max Desired f Max Torque --> X / Y / Z = Load [ms/Umdr] (Quantisierung der Einspritzzeit [ms/Umdr]) / RPM / Crank Angle BTDC ºDegrees (Zuendwinkellage ab BZM)
-KFZWS - Sicherheitszündwinkelkennfeld bei defektem Leerlaufschalter: Ignition Safety Map with a Defective Idle Switch --> X/Y/Z : Load (ms/RPM) / RPM / Crank Angle BTDC ºDegrees
eliotroyano:
Quote from: MIL_on on March 26, 2014, 02:14:27 PM
ok...i dont get what you want to tell me with the excel, because if you ask me that just shows that my guessing was correct?
The idea of the excel file is to show you my results from my calculations.
Quote from: MIL_on on March 26, 2014, 02:14:27 PM
the measured load vs. calculated load after my method:
yellow measured, orange calc (mLn/KHFM=Load [ms])
then divide your injection time by 2 (load is built by division mL/nmot and not combustion cycle which takes 720°!) and compare it to my calculated value mLn/KHFM. of course it doesnt fit perfect as for example the values i got from the internet (Qstat for the injectors for example) are different or bosch has changed the value slightly (red=inj. period/2, blue= mLn/KHFM [ms])
and then compare youre so called K against my KHFM... it all fits more or less? and that could or even should differ a little bit based on youre so called C, D, E
a logging file with a real driving condition would be interesting also because idling is always some kind of special situation...
Anyway as you said comparing K & KHFM for your calculation, mine and logs, both are very close. That was my point with excel file. Also some good logs will awesome to test the calculations.
Also C,D,E factors are that makes final injection period real. From Ti = (Tl * [C,D,E...]) + Tv, Tv will be TVUB or injectors battery voltage compensation. So C,D,E will temperature, altitude, etc..... The main idea is isolate KHFM as much as possible from load from logs taken to validate it formula.
MIL_on:
Regarding KFZW: If they were labeled that clear it wouldnt be a problem :D but in the damos i have the following KFZW with KFZW0, 1, 2 and additional the normal ones like KFZWOPT etc.
so what are the differences between KFZW0, KFZW1, KFZW2? i read somewhere that the M3.83 was already able to be used in combination with VVT. So one of them could be for the second Cam Position? Or do you just always change all 3 to the same value?
And what do you mean by telling KHFM in 8 bit? I am looking at a 18CG-File too and it is defined as 16 bit starting at 6A68 and containing the value 54AB Hex.
eliotroyano:
Quote from: MIL_on on March 26, 2014, 11:48:25 PM
Regarding KFZW: If they were labeled that clear it wouldnt be a problem :D but in the damos i have the following KFZW with KFZW0, 1, 2 and additional the normal ones like KFZWOPT etc.
so what are the differences between KFZW0, KFZW1, KFZW2? i read somewhere that the M3.83 was already able to be used in combination with VVT. So one of them could be for the second Cam Position? Or do you just always change all 3 to the same value?
Different versions of a MAP are used for different conditions, like in an automatic transmission, VVT, failure conditions, etc..... A good example of VVT with M383 is the Barzilian VW Gol 1.0 Turbo --> http://www.lunaticfringe.org/vwfox/specs/VW-Gol-1000-16v-turbo.html
Quote from: MIL_on on March 26, 2014, 11:48:25 PM
And what do you mean by telling KHFM in 8 bit? I am looking at a 18CG-File too and it is defined as 16 bit starting at 6A68 and containing the value 54AB Hex.
During my work with a M383 Damos sometimes I change the value in some constants (8 <--> 16 bits) looking for better interpretation. For example KHFM (84 @ 8bits / 43860 @ 16bits), FGAT0 (1.0001 @ 8bits / 13.0008 @ 16bits), NMAXF (60 @ 8bits / 7100 @ 16bits)......
About KHFM at the 18CG-File ( @16 bit it starts at 6A68 and containing the value 54AB Hex) I agree with you.
prj:
This discussion does not matter in the slightest if you are going to be doing any actual tuning.
You are going to hit 12.75 load and you are f…d
After that you can downscale load using KHFM and scale fuelling back up via FGAT0. Of course you will have to re-do all the timing maps, cold start etc.
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