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Title: KFZW - KFZWOP and tuning Post by: phila_dot on May 22, 2011, 03:13:19 PM I cannot find any concrete information on the process of moving from KFZW to KFZWOP and back. All that I can find in the Funktionsrahmen is in ZWGRU considering KFZW, "If the engine does not knock, entry of the optimum ignition angle".
Also, it appears that one of the prerequisites for both KFZW and KFZWOP are that Lambda=1. If that is the case, then what map is used when Lambda!=1? Just thinking logically, I would think that we would want to modify KFZWOP and have KFZW to fall back on. KFZWOP seems to be pretty agressive from the factory. Modules ZWGRU and MDBAS share the following: Variables: DZWOAG - exhaust gas recirculation rate depend. ignition angle correction of optimum ZW DZWOL - lambda depend. ignition angle correction of optimum ZW FNWUE - weighting factor overlap camshafts (intake) LAMBAS - base-lambda NMOT_w - motor speed RL_w - relative air charge (word) SY_NWS - system constant cam timing : no, 2 pt, or continuous TMOT - motor temperature WNWUE - camshaft overlap angle Parameter: DZWNWSUE - delta ignition angle dependant on camshaft overlap I hope that no one considers this beating a dead horse, but I didn't find any real clear information on this. My intent is for a consolidated thread discussing the facts, theories, and experiences tuning these maps. Title: Re: KFZW - KFZWOP and tuning Post by: julex on May 22, 2011, 04:21:36 PM From my limited experience it works this way: the timing gets its timing value REGARDLESS of lambda from KFZW, the description is wrong here alike how it is wrong with the fueling at "partial load" map.
Then it advances towards KFZWOP until knock is encountered. I am not sure or know which calibration for knock govern this behavior but, again, in my experience you want to set up your KFZW map to timing values where you already encounter at least 1.5 retard to "expedite" the learning at WOT. If you don't see 2.25-3.0 retard in your logs, you are wasting your performance potential. Title: Re: KFZW - KFZWOP and tuning Post by: nyet on May 22, 2011, 05:23:12 PM Then it advances towards KFZWOP until knock is encountered. I've never seen timing advance past KFZW at zero CF... or at least i've never seen it at WOT. I could be wrong though :( Title: Re: KFZW - KFZWOP and tuning Post by: julex on May 22, 2011, 07:00:43 PM Then it advances towards KFZWOP until knock is encountered. I've never seen timing advance past KFZW at zero CF... or at least i've never seen it at WOT. I could be wrong though :( Well, that's what theory says so no wonder it never moves up anyway. Maybe that works only within certain RPM delta as when you cruise at static RPM etc. For WOT you just need to log/tune period. Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on May 22, 2011, 07:05:52 PM If julex is correct, then there may be a better approach to this. Instead of forcing advanced timing it might be better to increase the rate that timing is advanced in the absence of knock. I revisited silentbob's post in the acceptable knock thread and added all the parameters he mentioned to my XDF. I haven't fully wrapped my head around it yet though.
What do you guys think? 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. His post seems to be more geared toward timing retardation than advancement though and I am not sure exactly what he means by "phased back to normal". Also, does the ECU consider any amount of knock acceptable or does the presence of any knock = timing retard? Title: Re: KFZW - KFZWOP and tuning Post by: nyet on May 22, 2011, 09:17:14 PM Instead of forcing advanced timing it might be better to increase the rate that timing is advanced in the absence of knock. Yes. KRANH and KRALH affect CF recovery (hysteresis). Both are in my XDF. Quote His post seems to be more geared toward timing retardation than advancement though Semantics :P There is only CF (retard). Recovery from CF is what you call "advancement". Quote and I am not sure exactly what he means by "phased back to normal". As far as I can tell, normal is CF = 0, and adaptation = 0 (i.e. actual = KFZW, not KFZWOP) Quote Also, does the ECU consider any amount of knock acceptable or does the presence of any knock = timing retard? From what I can tell, any time the ecu sees knock, and the window allows it, CF is increased by KRFKLN, until NKRAMAX is reached, upon which the long term retard term is increased by KRDWSA Title: Re: KFZW - KFZWOP and tuning Post by: nyet on May 22, 2011, 09:19:57 PM BTW from my reading of various papers (not the funktionsrahmen), KFZWOP is used to determine "actual" torque output using the optimal torque map, and comparing actual timing with KFZWOP. The more "actual" timing differs from KFZWOP, the lower the "actual" torque is (using the optimal torque map as a reference). I am unsure what maps govern this calculation.
Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on May 23, 2011, 12:05:30 AM Thanks nyet, although that is a little disappointing. So in your experience, KFZW is it. All the logs that I have seen agree with you, but they are also all WOT.
Maybe silentbob will join in and provide some clarity/confuse me. Title: Re: KFZW - KFZWOP and tuning Post by: Rick on May 23, 2011, 04:32:47 AM KFZWOP is never used for timing!
It is there so the ECU can calculate how much load is needed to generate the requested torque. The OP timing values are the timing values the engine produces most torque at if it were not limited by knock, which it always is. The ECU looks at the difference between optimum timing and actual timing. There is an equation which produces a factor by which is used to calculate the torque. Actual timing is will never increase beyond KFZW. You can tune the knock contol to do the following: Reduce the number of engine cycles needed to reduce the CF after knock stops being detected. Reduce the CF step size. Reduce the difference between current timing and adaptation map timing needed in order for the adaptation map to advance. Recalibrate knock sensor sensitivity. Rick Title: Re: KFZW - KFZWOP and tuning Post by: julex on May 23, 2011, 07:17:58 AM Rick: :-*
Well, that settles it then! Title: Re: KFZW - KFZWOP and tuning Post by: DJGonzo on May 23, 2011, 07:21:11 AM Awesome job Rick!
Right on point! KFZW is all you should need to tweak for basic timing changes. Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on May 23, 2011, 12:48:34 PM Thank you Rick, Nyet, and everyone else that contributed. This makes alot more sense now.
Title: Re: KFZW - KFZWOP and tuning Post by: silentbob on May 24, 2011, 08:12:24 AM KFZWOP is never used for timing! It is there so the ECU can calculate how much load is needed to generate the requested torque. The OP timing values are the timing values the engine produces most torque at if it were not limited by knock, which it always is. The ECU looks at the difference between optimum timing and actual timing. There is an equation which produces a factor by which is used to calculate the torque. Actual timing is will never increase beyond KFZW. ............ Just some details I want to add: Ignition angle can be earlier that KFZW as some corrections are applied to calculate zwgru. The engine is not knock limited on lower loads. A common mistake even big name Pro Tuner make is to put higher values in KFZW than in KFZWOP (Can happen if you use a different fuel. The values on knock limited areas are extrapolated out of a ignition angle sweep). This leads to the problem that the ECU will reduce the ignition angle far more than it has to if you have a torque intervention in that area resulting in poor drivability. In that case you would have to increase the values in KFZWOP as well. KFZW<= KFZWOP Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on May 28, 2011, 01:28:24 PM Thank you silentbob.
Please let me know if I am understanding this correctly. In order to recover from ignition retard faster, then I want to decrease the values in the maps KRVFN, KRLVFN, and KRVFSN. Also, increasing KRDWSA will increase the amount it is advanced and setting KRDWA to zero will allow it to fully recover. Should all three maps be lowered? If so, anyone have the address for KRLVFN? 0x19662 KRVFN - number of ignitions/cylinders, or time indication of an early adjustment to early adjustment (step-width KR) 0x????? KRLVFN - number of ignitions/cylinders, time indication of an early adjustment to early adjustment (slow early adjustment) 0x19672 KRVFSN - number of ignitions/cylinders, or time for quick adjustment of the early KR I am thinking of cutting all values in these maps in half, changing KRDWSA from 1.5 to 3, and KRDWA from 2.25 to 0. Am I on the right track? Has anyone done this? Is this idea and my values safe? Is there anything I am missing? Thanks again guys. Title: Re: KFZW - KFZWOP and tuning Post by: nyet on May 28, 2011, 06:41:46 PM I have mildly modified DWKRMSN, KRALH, KRANH, KRFKLN and KFFLLDE to no ill effect, as noted on the s4wiki: http://s4wiki.com/wiki/Tuning#Knock_recognition
Title: Re: KFZW - KFZWOP and tuning Post by: silentbob on May 29, 2011, 04:33:32 AM Thank you silentbob. You understood this right and you could do this, but it wouldn't make physical sense. Look at the calibration hints at KRRA in the Funktionsrahmen. l KRDWSA l <= l KRDWA l - l KRDWKLA l.Please let me know if I am understanding this correctly. In order to recover from ignition retard faster, then I want to decrease the values in the maps KRVFN, KRLVFN, and KRVFSN. Also, increasing KRDWSA will increase the amount it is advanced and setting KRDWA to zero will allow it to fully recover. Should all three maps be lowered? If so, anyone have the address for KRLVFN? 0x19662 KRVFN - number of ignitions/cylinders, or time indication of an early adjustment to early adjustment (step-width KR) 0x????? KRLVFN - number of ignitions/cylinders, time indication of an early adjustment to early adjustment (slow early adjustment) 0x19672 KRVFSN - number of ignitions/cylinders, or time for quick adjustment of the early KR I am thinking of cutting all values in these maps in half, changing KRDWSA from 1.5 to 3, and KRDWA from 2.25 to 0. Am I on the right track? Has anyone done this? Is this idea and my values safe? Is there anything I am missing? Thanks again guys. To adapt the knock threshold you should use a combination of KRDWA = KRDWSA and KRDWKLA = 0. Using a value KRDWSA (3) > KRDWA (0) doesn't make sense because if you have adapted a value of say 6 degrees and advance the ignition by 3 degrees if your current ignition retard is say 5.5 degrees you will make things worse. How fast you can phase the ignition retard back in is dependent on how fast the combustion chamber thermically regenerates from the increased temperature due to knocking cycles. If you phase it in to fast you will straight be into knock again. I don t know. Everybody here is so obsessed squeezing out the last bit of ignition angle. With 20psi + boost we are running resulting in ridiculously high peak cylinder pressures my strategy is to keep the engine out of the knock area. Even if kock doesn't f... up your engine instantly, your pistons will look like this over time (This is all assuming that knock detection is working 100% correct)(http://www.raceinfo.no/temp/tn_IMG_0174.jpg) Title: Re: KFZW - KFZWOP and tuning Post by: nyet on May 29, 2011, 02:51:12 PM Excellent post. I strongly favor not messing with the knock control (in particular, knock detection) very much.
Everybody here is so obsessed squeezing out the last bit of ignition angle. Agreed. And IMO there are better ways of getting more timing than dicking with KR... (race gas, lowering compression, water/meth etc).... Title: Re: KFZW - KFZWOP and tuning Post by: Rick on May 29, 2011, 04:33:49 PM My thoughts are a little different. IMO, people are overly scared of knock. What are peoples experience with tuning turbo engines? ME7 is the first I have tuned with such proper knock control, and If i'm honest so far it is hampering progress.
The piston pictured has been subjected to some serious det, I would think that is impossible with a correctly working tune. I have run many engines with very light audiable knock, i.e. detectable with a trained bare ear. Never have i seen that level of damage. Big boost engines often make their best power with slight knock, and can do this for 100k+ without effecting the engine life. Have you seen most timing logs for S4's? the ignition curve undulates like crazy - this is not optimum! I am pro ignition timing - it extracts the most efficiency from the engine, and runs the lowest temp. Rick Title: Re: KFZW - KFZWOP and tuning Post by: nyet on May 29, 2011, 04:43:02 PM Have you seen most timing logs for S4's? the ignition curve undulates like crazy I have not seen this in any properly tuned s4 with bone stock KR... what are you referring to? For very very fast S4s (including aggressively lightened cars) i've seen rate-of-load-increase related timing problems, but those are unrelated to KR. Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on May 29, 2011, 04:44:08 PM Thanks for putting that into perspective, that approach may be a little aggressive.
Unfortunately, I am having problems with the basics now. How are you guys determining what changes to make to KFZW and KFZW2 based on ECUx logs? RPM, load, and timing angle are not matching up between the logs and maps. Obviously, there are other factors effecting timing angle, but I am trying to make changes scientifically rather than on a whim. How do you determine if KFZW or KFZW2 needs to be changed? I am trying to work my CFs down after adjusting target AFR. Title: Re: KFZW - KFZWOP and tuning Post by: Rick on May 29, 2011, 05:58:23 PM Have you seen most timing logs for S4's? the ignition curve undulates like crazy I have not seen this in any properly tuned s4 with bone stock KR... what are you referring to? For very very fast S4s (including aggressively lightened cars) i've seen rate-of-load-increase related timing problems, but those are unrelated to KR. Nyet, i will dig some out. But, a stock car has very very conservative timing so there is no knock intervention. Phil - how would you tune ignition on a car without knock control? Rick Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on May 29, 2011, 06:17:31 PM Phil - how would you tune ignition on a car without knock control? Rick, I don't follow. I haven't touched KR. Title: Re: KFZW - KFZWOP and tuning Post by: NOTORIOUS VR on May 29, 2011, 07:46:20 PM The piston pictured has been subjected to some serious det, I'm going to say that wasn't even detonation that made the piston look like that... it looks like a foreign object made it into the CC and bounced around a while in there. Title: Re: KFZW - KFZWOP and tuning Post by: silentbob on May 30, 2011, 01:39:46 AM ;D
This is not a piston out of a random engine, but a RS4 with our oversensitive knock control posted by someone on audizine. That damage is most definately caused by knock. I can post some pictures of pistons from engines which were forced to knock in order to calibrate knock control if anyone wants to see it. I think nobody will argue that big boost engines will make best power on slight knock as they are obviously knock limited, but my thoughts are that with cylinder pressures easily exceeding 120bar I don't want to stress the engine hardware more than necessary and rather give up 10 hp. Title: Re: KFZW - KFZWOP and tuning Post by: NOTORIOUS VR on May 30, 2011, 08:25:57 AM ;D This is not a piston out of a random engine, but a RS4 with our oversensitive knock control posted by someone on audizine. That damage is most definately caused by knock. I can post some pictures of pistons from engines which were forced to knock in order to calibrate knock control if anyone wants to see it. I think nobody will argue that big boost engines will make best power on slight knock as they are obviously knock limited, but my thoughts are that with cylinder pressures easily exceeding 120bar I don't want to stress the engine hardware more than necessary and rather give up 10 hp. When ever you have a chance, I'd like to see the pics :) Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on May 31, 2011, 12:32:42 AM The only thing that still confuses me is KFZW vs KFZW2. The tuned files that I have seen modified KFZW and copied it into KFZW2. Is this the best approach? I would think that if it were optimal for them to be identical they would match from the factory or there would be no need for KFZW2 at all. The only thing I could find on this is a post by Tony, but I am still unsure how to balance the two maps.
One map is when the intake cam is at minimum advance, and the other map is when the intake cam is at maximum advance. The ECU interpolates the values based on the theoretical intake cam advance as it switches between the two. Title: Re: KFZW - KFZWOP and tuning Post by: silentbob on May 31, 2011, 04:50:29 AM The only thing that still confuses me is KFZW vs KFZW2. The tuned files that I have seen modified KFZW and copied it into KFZW2. Is this the best approach? I would think that if it were optimal for them to be identical they would match from the factory or there would be no need for KFZW2 at all. The only thing I could find on this is a post by Tony, but I am still unsure how to balance the two maps. One map is when the intake cam is at minimum advance, and the other map is when the intake cam is at maximum advance. The ECU interpolates the values based on the theoretical intake cam advance as it switches between the two. It's exactly how Tony discribed it. I have also seen this copy thing you discribed on many files from various tuners. I know why they do it, but it's complete bullshit (or lets say unprofessional) in my opinion. Usually when a calibration is done the engine is measured over the hole operating range with in our case two camshaft timings. Based on the measurements it's decided what cam phasing is used on which operating point. The two maps contain the values out of this measurements. So the ignition angles for both phasings are optimal even if you have a fault in the system and the cam is stuck in one position. What tuners usually do is put the car on the dyno with whatever cam phasing is calibrated and tune ignition angle. To make things easier they put the same calibration in both maps. Now if you have a fault in the cam switching system you will have wrong ignition angles in the area were the cam would have been in an other position. It's not that critical on our engines because the max difference in timing is "only" 20 degrees, but it can become on engines were you have up to 60 degrees. Title: Re: KFZW - KFZWOP and tuning Post by: s5fourdoor on May 31, 2011, 03:36:32 PM So are we advocating running the same maps on KFZW and KFZW2 then?
The changeover map is KFNW, right? I can't find anything which shows how to "stitch" the maps together with respect to KFNW. Could somebody possibly share their KFZW/KFZW2 maps with us? I like what Rick said regarding knock/tuning, but I'd personally rather avoid knock if possible... Title: Re: KFZW - KFZWOP and tuning Post by: julex on May 31, 2011, 04:15:41 PM realistically you should only tune the last column for maximum load as this is where timing matters the most. Leave the rest at factory.
Since you also have changeover map that tells you when cam adjustment takes place, you should make adjustment to timing map 1 before and timing 2 after the cam shift leaving the other stuff alone. This will leave the maps in their factory state should anything fail in cam timing mechanism. If you want to be completely accurate you could probably increase the "dead" timing area in map 1 with delta change at the same rpm/load in map 2 and vice verse. This way, should your NWS fail, you will still get higher timing but not as much as just copying of the values. that's my take on it. Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on June 02, 2011, 11:06:15 PM I need a little help with understanding the schematic. What is the circle with the plus or minus next to it? Also, what is the asterisk in the box? These aren't explained in the beginning. I have included my general understanding below.
(http://nyet.org/cars/images/KFZW-vs-KFZW2.jpg) The output from KFZW is input into the partial function ZW_NWS as zw_local. fnwue = 1 is the maximum possible overlap of the inlet camshaft and determines whether KFZW or KFZW2 is used in ZW_NWS. I have not completely figured out the origin of fnwue, but I didn't see any relation to KFNW. If SY_NWS = 0, then zwnws = zw_local (does not apply). If SY_NWS = 1 and fnwue < 1, then zwnws = zw_local? If SY_NWS = 1 and fnwue = 1, then zwnws = the output from KFZW2? If SY_NWS = 2, then zwnws = the output from DZWNWSUE (does not qpply)? zwnws is effected by KFDZWKG, dzwoag, and dzwol (I believe all = 0) and is the output as zwgru - Basic ignition Title: Re: KFZW - KFZWOP and tuning Post by: silentbob on June 03, 2011, 12:44:18 AM I need a little help with understanding the schematic. What is the circle with the plus or minus next to it? Also, what is the asterisk in the box? These aren't explained in the beginning. I have included my general understanding below. The output from KFZW is input into the partial function ZW_NWS as zw_local. The circle is just a summation point and the asterisk is the sign for a multiplication. Simple as that ;) fnwue = 1 is the maximum possible overlap of the inlet camshaft and determines whether KFZW or KFZW2 is used in ZW_NWS. I have not completely figured out the origin of fnwue, but I didn't see any relation to KFNW. If SY_NWS = 0, then zwnws = zw_local (does not apply). If SY_NWS = 1 and fnwue < 1, then zwnws = zw_local? If SY_NWS = 1 and fnwue = 1, then zwnws = the output from KFZW2? If SY_NWS = 2, then zwnws = the output from DZWNWSUE (does not qpply)? zwnws is effected by KFDZWKG, dzwoag, and dzwol (I believe all = 0) and is the output as zwgru - Basic ignition Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on June 03, 2011, 07:58:21 AM Thank you for the reply silentbob. I apologize for not being clear in my post.
I need a little help with understanding the schematic. What is the circle with the plus or minus next to it? Also, what is the asterisk in the box? These aren't explained in the beginning. I have included my general understanding below. The output from KFZW is input into the partial function ZW_NWS as zw_local. The circle is just a summation point and the asterisk is the sign for a multiplication. Simple as that ;) How does the - circle + or + circle + effect the data and flow? I assumed the asterisk in the box was multiplication, but in the beginning it is defined as a box with an x. fnwue = 1 is the maximum possible overlap of the inlet camshaft and determines whether KFZW or KFZW2 is used in ZW_NWS. I have not completely figured out the origin of fnwue, but I didn't see any relation to KFNW. If SY_NWS = 0, then zwnws = zw_local (does not apply). If SY_NWS = 1 and fnwue < 1, then zwnws = zw_local? If SY_NWS = 1 and fnwue = 1, then zwnws = the output from KFZW2? If SY_NWS = 2, then zwnws = the output from DZWNWSUE (does not qpply)? zwnws is effected by KFDZWKG, dzwoag, and dzwol (I believe all = 0) and is the output as zwgru - Basic ignition I can see where fnwue is created, however, I have not yet worked out how it is set. If camshaft control is simply on/off, then why is there a need for interpolation. I just want to make sure that I have a complete understanding and I do not like to assume things. Thank you for your patience. Title: Re: KFZW - KFZWOP and tuning Post by: silentbob on June 03, 2011, 09:50:20 AM How does the - circle + or + circle + effect the data and flow? I assumed the asterisk in the box was multiplication, but in the beginning it is defined as a box with an x. It's just a summation (+1) + (-fnwue) for example. I can see where fnwue is created, however, I have not yet worked out how it is set. If camshaft control is simply on/off, then why is there a need for interpolation. I just want to make sure that I have a complete understanding and I do not like to assume things. Thank you for your patience. Example: Cam is in it's normal position (fnwue=0 -> zwnsw = zw_local * (1-0) + KFZW2*0=zw_local) Cam half of the way to the end position (fnwue=0,5 -> zwnsw = zw_local (1-0,5) + KFZW2 * 0,5) Cam in end position (fnwue=1 -> zwnsw = zw_local* (1-1) + KFZW2 *1= KFZW2) ;) Title: Re: KFZW - KFZWOP and tuning Post by: s5fourdoor on June 03, 2011, 10:19:44 AM It seems to me that KFNW is fnwue. Thats my guess...
Title: Re: KFZW - KFZWOP and tuning Post by: nyet on June 03, 2011, 12:09:48 PM I'm still confused. Like phila_dot says, the 2.7t cams are in one of only two positions.
its either a*0 + b*1 or a*1 + b*0 Title: Re: KFZW - KFZWOP and tuning Post by: silentbob on June 03, 2011, 12:34:16 PM During the switching process it's not (thought it's only a short amount of time).
The engine has a cam sensor on each bank. The ECU knows exactly were the cam is. It's not just 0->1 Title: Re: KFZW - KFZWOP and tuning Post by: s5fourdoor on June 03, 2011, 02:13:27 PM Perhaps its the zero-one thresholding which is a basic algebraic technique. If you have two states, you can create an arbitrary combination of values between the two state values, by using a sliding amount of weight place on each state.
so: A * state_1 + B * state_0 given that: A + B = 1 and A > 0 and B > 0 Another basic way of saying this is that values are being Blended. I would guess the "blending" is being handled by the KNFW table, possibly with the RPM as some input. Thats my guess anyways... Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on June 03, 2011, 11:06:44 PM It seems to me that KFNW is fnwue. Thats my guess... KFNWSE does in fact become fnwue after going through NWSOLLE, BGARNW, GGNW, and NWWUE. There are alot of influences along the way. However, the source for KLFNWE is fnwue. I have not been able to locate this characteristic though. Title: Re: KFZW - KFZWOP and tuning Post by: Rick on June 04, 2011, 04:13:08 AM The interpolation is used when the cam is switching.
Although it can only be controlled between 2 positions, when it changes state from one position to another, it takes a finite amount of time for this to happen. During this time, it will not be at either position, but somewhere in between and so the ignition angle is calculated for this point. Rick Title: Re: KFZW - KFZWOP and tuning Post by: vwaudiguy on June 04, 2011, 10:37:02 AM How long does this transition take? I assume it would be expressed in engine cycles? Does oil pressure have any effect (ie. lower rpm transition takes longer) Or I guess the transition always takes place at the same rpm/coolant temp? This transition is primarily for emmisions? Sorry for 20 ?'s :)
Title: Re: KFZW - KFZWOP and tuning Post by: setzi62 on June 13, 2011, 01:49:54 AM How long does this transition take? I assume it would be expressed in engine cycles? I monitored camshaft switchover and for the monitored car (150PS 1.8T) it takes roughly 120ms for the changeover, see attached image. Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on June 14, 2011, 10:54:24 AM I have worked out KFNW's "influence" on zwgru in the spreadsheet that I use. I will post it when I get the chance.
Setzi, have you compared the fnwue values that you logged vs KFNW? I have not gotten the chance to work out everything between KFNW and fnwue yet. If you can post the log I would like to compare it to my theoretical values. Edit: Tuning KFZW and KFZW2 based off of my integrated KFNW values has worked as desired. Title: Re: KFZW - KFZWOP and tuning Post by: s5fourdoor on June 14, 2011, 11:13:29 AM I have worked out KFNW's "influence" on zwgru in the spreadsheet that I use. I will post it when I get the chance. Setzi, have you compared the fnwue values that you logged vs KFNW? I have not gotten the chance to work out everything between KFNW and fnwue yet. If you can post the log I would like to compare it to my theoretical values. Edit: Tuning KFZW and KFZW2 based off of my integrated KFNW values has worked as desired. boss! its amazing to watch this unravel. Title: Re: KFZW - KFZWOP and tuning Post by: setzi62 on June 16, 2011, 03:32:52 AM I have worked out KFNW's "influence" on zwgru in the spreadsheet that I use. I will post it when I get the chance. Here are the logs. In this case I logged only small number of other values, don't know if thisSetzi, have you compared the fnwue values that you logged vs KFNW? I have not gotten the chance to work out everything between KFNW and fnwue yet. If you can post the log I would like to compare it to my theoretical values. would reveal something. I did not yet look at the contents of the related maps (KFNWSE, FNWTME, ...) to understand at which conditions the camshaft change should take place. Title: Re: KFZW - KFZWOP and tuning Post by: playgoods on June 16, 2011, 01:14:01 PM Sorry if I am off topic here. I am reading and seeing all the codes KFNW, KFZWOP ect.
I take it these are names of maps. Are these locations or what exactly are the meanings? Title: Re: KFZW - KFZWOP and tuning Post by: bazaa on June 16, 2011, 01:53:22 PM They are German abbreviations of the maps names
read the wiki it will help you understand them http://www.nefariousmotorsports.com/wiki/index.php/Main_Page also see nyet's wiki http://s4wiki.com/wiki/Tuning Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on June 19, 2011, 04:37:12 PM I have attached a sample of the spreadsheet that I use when tuning KFZW and KFZW2.
Thank you for the logs Setzi. I have been traveling all week, so I have not gotten a chance to look at them yet. I am not sure if it is just my XDF, but I can only increment these maps by multiples of 0.75. Title: Re: KFZW - KFZWOP and tuning Post by: julex on June 20, 2011, 09:55:57 AM I am not sure if it is just my XDF, but I can only increment these maps by multiples of 0.75. Switch to Hex mode display and once you increment by 1 you'll notice that it is calculated to 0.75deg when you go back to "normal" mode. You can see the conversion routine for each table/scalar once you go into edit mode for XDF parameter. Title: Re: KFZW - KFZWOP and tuning Post by: s5fourdoor on June 20, 2011, 10:38:22 AM Are you running water/meth? The curves seem pretty aggressive for a high boost car. Believe me, I am no expert and do not claim to be, but I was just commenting mostly to stimulate discussion and to get an idea of what is safe / dangerous here.
Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on June 20, 2011, 02:22:51 PM Are you running water/meth? The curves seem pretty aggressive for a high boost car. Believe me, I am no expert and do not claim to be, but I was just commenting mostly to stimulate discussion and to get an idea of what is safe / dangerous here. If that question was directed towards me, then yes. 17 psi boost, good ole cali 91 octane, and Vast/Devil's Own meth kit 50:50 M1 to distilled water from 4 psi to 14 psi. I only included the tuned KFZW tables to illustrate the change sheet. Title: Re: KFZW - KFZWOP and tuning Post by: s5fourdoor on June 20, 2011, 05:21:40 PM Ahh, gotcha. Yah that sheet is pretty awesome man... thanks for uploading it. Huge contribution in my opinion. Do you know of anyone that changed the KFNW table itself? Or is it advisable not to change that?
Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on June 20, 2011, 09:53:34 PM Ahh, gotcha. Yah that sheet is pretty awesome man... thanks for uploading it. Huge contribution in my opinion. Do you know of anyone that changed the KFNW table itself? Or is it advisable not to change that? The thread below is the only thing that I have seen on the topic. http://www.nefariousmotorsports.com/forum/index.php?topic=279.0title= Title: Re: KFZW - KFZWOP and tuning Post by: LHN86 on July 26, 2012, 03:31:57 PM I have another question. Do you actualy have to change the load table while you are tuning the KFZW maps?
Title: Re: KFZW - KFZWOP and tuning Post by: Mantis on June 18, 2013, 06:19:05 AM If your KFZW approaches KFZWOP should you consider altering re increasing KFZWOP?
My M75 tune has no timing correction, I continued to increase base timing in KFZW until I found it easier to just copy KFZWOP and paste into KFZW. Of course I had to make the final two column values the same as the axis values are not shared. I am still not seeing any timing correction, should I consider scaling KFZWOP overall by say 10%, that would at least give my timing a point to move towards under optimum conditions? Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on June 18, 2013, 06:44:58 AM Timing does not move towards KFZWOP under any condtions.
KFZWOP is only used to evaluate ignition angle efficiency for numerous interventions. You can tune it to preserve these interventions, but that is the only benefit. This is ignition timing...you're saying that the flame speed and cylinder pressures are the same between the last two load points? It's bad enough that you're capped at 191.25. Also, this would mean that you're whole table is shifted down. Don't make the last two load columns the same. Interpolate the values for the missing KFZWOP column. KFZWOP only applies to petrol at lambda 1 anyway. Title: Re: KFZW - KFZWOP and tuning Post by: Mantis on June 18, 2013, 06:57:32 AM I understand that it is an evaluation point and from earlier in this thread you noted that it was only used when lambda is 1, my question was is there any benefit to moving KFZWOP higher as I am able to easily achieve the values prescribed by the factory tune.
I can extrapolate the final KFZW values, I have rescaled the 11 point timing load axis to a max of 238.68 and second to last at 206.34, both of those values are above 191, I assume I could just tweak these values as opposed to extrapolating. Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on June 18, 2013, 07:12:45 AM KFZWOP isn't only used at lambda 1, it represents optimum timing at lambda 1 (petrol).
I suggest not touching KFZWOP. It is mainly used in the torque model. You rescaled the load axis in KFZW? What software are you using? M box uses 8 bit load for KFZW(2), so the axis cannot be rescaled. KFZW and KFZWOP load axis have identical values except that KFZWOP doesn't have one load point (39 IIRC). The values can be interpolated. Title: Re: KFZW - KFZWOP and tuning Post by: Mantis on June 18, 2013, 07:31:59 AM Sorry my bad, I mistakenly thought KFZW shared an axis with KFMIOP
Title: Re: KFZW - KFZWOP and tuning Post by: Mantis on June 18, 2013, 01:34:16 PM Phila, I noticed you bracketed that KFZWOP is optimum timing for petrol, any idea what optimum timing for alcohol would be, if I do change any of KFZWOP is there anything you wold recommend that I log, anything that you would personally like to see in a log?
Title: Re: KFZW - KFZWOP and tuning Post by: overspeed on June 18, 2013, 02:41:05 PM Don´t know if it is what you want to know, but from C20 to E100 I usually add about 6~8° to timing...
That´s something you~ll probably notice, if you have low CR (and/or boost) you can get maximum power with no retard... with higher CR and boost as near you get to detonation more power you get... even with low degrees of CF (about 1,5 to 4,5°) Title: Re: KFZW - KFZWOP and tuning Post by: 20VTMK1 on December 05, 2013, 01:23:56 PM Question ..
If there are no CF's but actual timing is almost always lower than requested by approx. 4-5 degree's , could this be some form of correction ? Its not boost related coz this happens when actual boost is lower than requested as well .. Any ideas ? Thanks Title: Re: KFZW - KFZWOP and tuning Post by: tbm on December 05, 2013, 01:45:36 PM Question .. If your actual timing is lower 0 then your KFZW is bigger than KFZWOP. Also it may happens if works some corrections from IAT and LAMFA. Check your DZWOLA, ETADZW, DZWETA and KFZWWLNM. Also you can log zwbas, zopt, zwsol and etazwbm it may help you to solve this reducing.If there are no CF's but actual timing is almost always lower than requested by approx. 4-5 degree's , could this be some form of correction ? Its not boost related coz this happens when actual boost is lower than requested as well .. Any ideas ? Thanks Title: Re: KFZW - KFZWOP and tuning Post by: 20VTMK1 on December 06, 2013, 01:26:19 PM the actual timing is not lower than zero , it is lower by ~ 5 deg than the requested .
I did check KFZWOP , it is higher than KFZW be a fair margin. I don't see any load correction for IAT and coolant . Lamfa correction , do you mean for component protection ?Actual vs requested lambda is spot on bar a few places were actual is lower . Am I missing something here ?? Perhaps some sort of maf correction or load correction ? BTW , the actual and requested load is also almost spot on ... Thank you , I will log the blocks you mention if not already in my list .. Title: Re: KFZW - KFZWOP and tuning Post by: bk56190 on December 07, 2013, 05:21:08 AM Read th FR again, KFDZWKG, DZWOLA...
Title: Re: KFZW - KFZWOP and tuning Post by: phila_dot on December 07, 2013, 03:09:09 PM Question .. If there are no CF's but actual timing is almost always lower than requested by approx. 4-5 degree's , could this be some form of correction ? Its not boost related coz this happens when actual boost is lower than requested as well .. Any ideas ? Thanks What variables are you referring to as actual (zwout?) and requested (zwgru)? If your actual timing is lower 0 then your KFZW is bigger than KFZWOP. Also it may happens if works some corrections from IAT and LAMFA. Check your DZWOLA, ETADZW, DZWETA and KFZWWLNM. Also you can log zwbas, zopt, zwsol and etazwbm it may help you to solve this reducing. This is mostly nonsense. the actual timing is not lower than zero , it is lower by ~ 5 deg than the requested . I did check KFZWOP , it is higher than KFZW be a fair margin. I don't see any load correction for IAT and coolant . Lamfa correction , do you mean for component protection ?Actual vs requested lambda is spot on bar a few places were actual is lower . Am I missing something here ?? Perhaps some sort of maf correction or load correction ? BTW , the actual and requested load is also almost spot on ... Thank you , I will log the blocks you mention if not already in my list .. This is really confusing. How are you jumping from timing retard to all of these unrelated questions? Look at %ZUE in the FR and it should be pretty clear how requested timing is offset or overridden. Title: Re: KFZW - KFZWOP and tuning Post by: 20VTMK1 on December 08, 2013, 08:46:03 AM Apologies ,
Was trying best to respond to this "If your actual timing is lower 0 then your KFZW is bigger than KFZWOP. Also it may happens if works some corrections from IAT and LAMFA. Check your DZWOLA, ETADZW, DZWETA and KFZWWLNM. Also you can log zwbas, zopt, zwsol and etazwbm it may help you to solve this reducing." ZWGRU is Req and ZQOUT is actual , yes . I am looking into the functionsramen . Thanks for that. Title: Re: KFZW - KFZWOP and tuning Post by: tbm on December 08, 2013, 10:21:53 AM This is mostly nonsense. Why? Could you explain? All these things can affect zwout.Title: Re: KFZW - KFZWOP and tuning Post by: tbm on December 08, 2013, 10:23:55 AM Lamfa correction , do you mean for component protection ? No, I meant dzwola.Title: Re: KFZW - KFZWOP and tuning Post by: vwaudiguy on April 17, 2015, 11:42:26 AM Sorry to bump this old thread, but I didn't see 20v's question completely answered, or maybe I missed it. I also see around 5 degrees less advance than requested in KFZW at rpm above 5k. No cf, and no IAT correction looking at KFZWWLNM. Can anyone suggest what other maps to look at that apply corrections? Thanks.
Title: Re: KFZW - KFZWOP and tuning Post by: littco on April 20, 2015, 03:32:48 AM Sorry to bump this old thread, but I didn't see 20v's question completely answered, or maybe I missed it. I also see around 5 degrees less advance than requested in KFZW at rpm above 5k. No cf, and no IAT correction looking at KFZWWLNM. Can anyone suggest what other maps to look at that apply corrections? Thanks. On your Kfzw and Kfzw2 maps, what timings values is it requesting and what load values/rpm on the axis.. as per usual a log would help.. Title: Re: KFZW - KFZWOP and tuning Post by: woj on December 03, 2017, 11:16:03 AM I'll bump it too, the question of what one does with KFZWOP for alcohol fuels (E85/E100) has been asked at least twice in different threads, but not answered (or I did not search sufficiently). The common information (not only from here) about ZW is that for E85/100 fuels you can raise it by 6-8 degrees safely, due to higher (or no) knock limit, from what I understand. But that does mean that one gets closer to KFZWOP which is more or less the same, or that the KFZWOP also moves by large amounts of degrees? If the latter (which is the case by my educated guess), what are the ball parks?
The source of the question: although on ME7.9.10 the ZW is mostly way down below of ZWOP in boost areas, there are sites where it is very close or *at* ZWOP in mid-load under boost. Read earlier in this thread that having ZW over ZWOP is no good due to ill effects of knock recovery, torque interventions, etc. So tuning ZW up by 6-8 degrees (or even 2-4 degrees in some cases) and staying below ZWOP is not possible without touching ZWOP. Yes, I know I can just raise it, but what are the sensible numbers here? Another thing - in cam regulated ME-s there is ZWOP1 and ZWOP2 (no surprise here), but in the torque monitoring module there is just one KFZW_UM. The FR says that this is the same as ZWOP *or* ZWOP2, "or" being the puzzle. Per cell maximum of the two? EDIT: OK, finally found this: http://nefariousmotorsports.com/forum/index.php?topic=10294.msg89969#msg89969 And it says that essentially guessing ZWOP and keeping it over ZW is the only way to go. The other question about the torque monitoring stands though. |