Pages: 1 2 [3] 4 5 6
Author Topic: Acceptable limits for knock voltage  (Read 43947 times)
Rick
Hero Member
*****

Karma: +62/-3
Offline Offline

Posts: 704


« Reply #30 on: March 21, 2011, 04:51:13 AM »

Can you elaborate a little? Ignition is retarded by adaptation at those load points where  correction is always required?

Yes it is, but only in certain conditions, and it can and is reset during certain conditions.  Again, there a maps to tune this!

Rick
Logged
turboskipper
Jr. Member
**

Karma: +3/-0
Offline Offline

Posts: 40


« Reply #31 on: March 23, 2011, 12:30:56 PM »

Can you elaborate a little? Ignition is retarded by adaptation at those load points where  correction is always required?

Yes it is, but only in certain conditions, and it can and is reset during certain conditions.  Again, there a maps to tune this!

Rick

Buy why do you want to always have correction active? Maybe a degree or two but seems to me you don't want to be relying on 6-7 degrees of correction factor all the time. For one the adapts can take place. Second you leave yourself less room for retard if you really need it (got a bad tank of fuel, meth ran out, etc). If I was going to play with the knock control I'd get my spark as close to ideal as possible with knock control off and det cans and then with knock control on I'd want 1-2 degrees of correction in normal situations.
Logged
carlossus
Sr. Member
****

Karma: +37/-0
Offline Offline

Posts: 394

Leon Curpa Stg1+


« Reply #32 on: March 23, 2011, 12:46:34 PM »

I'm not saying this is a desirable situation, but it's worth knowing that if you were running too much advance at max load and after a few weeks you checked your CF's they would look OK, but in reality adaptation has knocked off a few degrees of advance already; but only at that specific load condition.
Logged
silentbob
Full Member
***

Karma: +29/-1
Offline Offline

Posts: 141


« Reply #33 on: March 23, 2011, 12:55:05 PM »

I'll do a short writeup on that topic till the weekend.
Logged
nyet
Administrator
Hero Member
*****

Karma: +423/-49
Offline Offline

Posts: 9458


WWW
« Reply #34 on: March 24, 2011, 01:37:43 PM »

Buy why do you want to always have correction active?

Depends in which environment you are tuning. Personally, I like to tune timing in the worst case enviroment (high IATs, etc) and have enough correction so the car is faster when conditions are good.

In any case, I don't think you'll EVER max out correction if you are generally running 6-7 degrees.

YMMV.
Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

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 experience.
nyet
Administrator
Hero Member
*****

Karma: +423/-49
Offline Offline

Posts: 9458


WWW
« Reply #35 on: March 24, 2011, 01:40:16 PM »

I'll do a short writeup on that topic [long term timing adaptation] till the weekend.

Yes, please!

I will add that to the s4 wiki as well since i know such a thing exists, but i was never clear on the details.
Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

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 experience.
carlossus
Sr. Member
****

Karma: +37/-0
Offline Offline

Posts: 394

Leon Curpa Stg1+


« Reply #36 on: March 24, 2011, 04:31:18 PM »

This thread may cross the line into epic.
Logged
nyet
Administrator
Hero Member
*****

Karma: +423/-49
Offline Offline

Posts: 9458


WWW
« Reply #37 on: March 24, 2011, 08:13:11 PM »

This thread may cross the line into epic.

Definitely. FWIW here is all i have that refers to long term timing advance (retard?) adaptation

http://s4wiki.com/wiki/Timing

See the "questions" section.
Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

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 experience.
silentbob
Full Member
***

Karma: +29/-1
Offline Offline

Posts: 141


« Reply #38 on: March 25, 2011, 04:48:04 PM »

First I want to mention, that unfortunately you can t directly see the activities of the adaption with the variables you can log with ECUx, VCDS as the corresponding ones are not included. Easiest would be to have the proper A2l but maybe the software disassembling guys will dig them up some time Wink
I ll again simplify some stuff for better understanding.

What you see in the logs is the variable dwkrz(x) which is the delta ignition angle that is passed on to the ignition module in the software. Depending on operating conditions it can represent different variables.
Most important one is when knock control is active (not meaning that it pulls ignition angle but that it s not inactive due to cold engine(TMKR), low load(LKRN) for example), it s not in idle control and there is no safety retard due to failures for example in the knock sensor ciruit: dwkrz(x) = wkr (x)
wkr(x) is the RAM area where the ignition retards are summed up for each cylinder.
Without adaption knock control retards the ignition angle individualy for every cylinder by KRFKN(KRFKLN in stationary mode) with every recognized knocking cycle and sums it up in wkr(x).
wkr(x) is limited to KRMXN (which is the max value incl. adaption) on retard and 0 on advance of ignition.
For advancing the values in wkr (x) back to 0 the counter zkrvf(x) is used. It is initialized on every knocking cycle with the values out of KRVFN which controls how fast the ignition is phased back to normal. For every non knocking cycle were the ignition angle is limited due to knock control activity, this counter is decremented by 1. When the counter is 0 the ignition angle is advanced by 1 degree and reinitialized with KRVFN.
Now the adaption comes into play. The map for the adaption values in RAM is wkra (x). The axes are load (KRALx) and RPMs (KRANx).

How does the adaption learn the values:
When adaption is active ( TCO>TMKRA + knock control is active) and writing into the adaption map is not forbidden due to rl < LKRAN, TCO<TMKRAS, N<NKRAMIN, N>NKRAMAX, ASR, VMAX,NMAX, then the values of wkr(x)+KRDWKLA (which is 0 on S4/RS4) is written into the adaption map if the value is more retarded than the saved value in wkra(x).
If the current ignition retard in wkr(x) is more than KRDWA earlier than the stored value in wkra(x) and zkrvf(x)=0 the value in the adaption map is advanced by KRDWSA.

How are the adaption values used for ignition angle calculation:
As already mentioned the variable that influences ignition calculation is dwkrz(x) = wkr (x).
The values of wkr (x) are overwritten with the values out of wkra (x) when the adaption is active (conditions see above).

Summed up:
What you see in your logs are applied ignition corrections of the knock control including adaption values. The maximum retard due to knock control is limited to KRMXN! If you learn high adaption values it will take the adaption quite a while to get ign <back to normal>.
The mean value of the last 6 ignition corrections dwkrz(x) due to knock control also influence the max. allowed load in LDRXN. It has a long term adaption which becomes active above RLKRLDA.
The correction factor for LDRXN can be found in KFFLLDE. How fast the adaption works can be influenced by TLKRLDAB and TLKRLDAU.
If there are any specific questions just feel free to ask.
« Last Edit: September 13, 2011, 05:31:01 PM by silentbob » Logged
Rick
Hero Member
*****

Karma: +62/-3
Offline Offline

Posts: 704


« Reply #39 on: March 26, 2011, 12:59:08 PM »

I find it useful to make KRDWA small.  What this means is that if your knock tendancy reduces, the adaptation map changes quickly, so you should always be optimum.

Rick
Logged
vwaudiguy
Hero Member
*****

Karma: +47/-35
Offline Offline

Posts: 1963



« Reply #40 on: April 18, 2011, 11:14:04 PM »

Couldn't you clear dtc's and repeat logging to catch the system in an unmodified state (as far as the overall correction factor of overall ign timing)? Taking note of cf factor and overall ign timing? I apologize if this sounds stupid!
Logged

"If you have a chinese turbo, that you are worried is going to blow up when you floor it, then LOL."
julex
Hero Member
*****

Karma: +77/-4
Offline Offline

Posts: 923


« Reply #41 on: April 19, 2011, 02:20:26 PM »

I find it useful to make KRDWA small.  What this means is that if your knock tendancy reduces, the adaptation map changes quickly, so you should always be optimum.

Rick

KRDWA is not defined in XDF floating around forums. Where can I access data that would show address locations for different maps/constants/etc in M-box?

Thanks.
Logged
nyet
Administrator
Hero Member
*****

Karma: +423/-49
Offline Offline

Posts: 9458


WWW
« Reply #42 on: April 19, 2011, 06:52:00 PM »

I have

4Z7907551R 0x11252
F 0x10fde
G 0x110a9

I will look for it in M box time permitting
Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

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 experience.
nyet
Administrator
Hero Member
*****

Karma: +423/-49
Offline Offline

Posts: 9458


WWW
« Reply #43 on: April 19, 2011, 07:00:07 PM »

Also, is there a way to read the current long term KR adaptation?

If not, but if it does exist somewhere in ecu memory, can you convince nefmoto to add it to his ecux alternative Smiley
Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

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 experience.
phila_dot
Hero Member
*****

Karma: +157/-11
Offline Offline

Posts: 1705


« Reply #44 on: April 19, 2011, 10:36:08 PM »

I find it useful to make KRDWA small.  What this means is that if your knock tendancy reduces, the adaptation map changes quickly, so you should always be optimum.

Rick

KRDWA is not defined in XDF floating around forums. Where can I access data that would show address locations for different maps/constants/etc in M-box?

Thanks.


KRDWA
Knock control adaptation to differential current ZW map
0x1109D
Factor : 0.750000
Logged
Pages: 1 2 [3] 4 5 6
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.027 seconds with 18 queries. (Pretty URLs adds 0s, 0q)