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The effects of AFV on open loop areas

Started by 1FSTRK, September 28, 2011, 10:27:06 AM

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whittlebeast

At one point I had 4 different o2 sensors on a car I was messing with.  Two wide bands and 2 narrow bands.  I learned to not do that as you will start to question everything.

Whenever we dyno tune a car with onboard wide band, the first thing we do is verify that the car wide band matches my wide band and the one that the dyno is using.  We normally pick the car one as gospel if the car is running full feedback and just deal with it at the dyno.   I had the guy that owns the Mustang install a couple of test bungs in the exhaust for just this reason.  When things get ugly we toss a known good heated narrow band in the exhaust and use it to find stoich.

Beast
Dynos are great for getting the motor close enough to get on the data loggers.

04FLHP

It seems to me he OP is suggesting the use of the second sensor to fill in the areas that you can not take readings using the bikes narrow bands.

Not as a second opinion but as a way to calculate VEs from an O2 reading at 90 and 100kpa throughout the rpm range. I can see that you may be off by X% but at least you would have the VEs correct in each cell in those columns. After that tune the AFR table for power and the VEs should be fine when the AFV kicks in. If the two sensors disagree by 8% the day of the test in the 70 and 80% columns while the narrow bands are active then it is safe to use that as the correction in the 90 and 100% columns when testing with just the broad bands.
Steve said it best do not fight the ECM but that does not mean that you can not work with the ECM through the use of additional sensors if done properly. EGTs can be used also to work the upper areas but I think you would take a chance that the mixture was right but you would not know if the VEs were wrong and that is where the AFV would later be a problem.

Steve Cole

Quote from: 04FLHP on October 14, 2011, 09:02:42 AM
It seems to me he OP is suggesting the use of the second sensor to fill in the areas that you can not take readings using the bikes narrow bands.

Not as a second opinion but as a way to calculate VEs from an O2 reading at 90 and 100kpa throughout the rpm range. I can see that you may be off by X% but at least you would have the VEs correct in each cell in those columns. After that tune the AFR table for power and the VEs should be fine when the AFV kicks in. If the two sensors disagree by 8% the day of the test in the 70 and 80% columns while the narrow bands are active then it is safe to use that as the correction in the 90 and 100% columns when testing with just the broad bands.
Steve said it best do not fight the ECM but that does not mean that you can not work with the ECM through the use of additional sensors if done properly. EGTs can be used also to work the upper areas but I think you would take a chance that the mixture was right but you would not know if the VEs were wrong and that is where the AFV would later be a problem.

The AFV will only adjust if the ECM see a different reading than what it's set for. For the most part you've hit the nail on the head. Let the ECM and O2 do what it wants and get the VE's calibrated with little to no offset. Now the ECM is happy and there will be no AFV and no integrator adjustments being made. This is the key to it all! Now that you see where the ECM wants things with no offsets you can start changing other adjustments to get it richer or leaner. For the areas outside the range that the ECM doesnot use the O2's you can trim in with something else if you like. The biggest issue to watch for in those areas is any difference between the two different systems so the blend point between them is smooth. If you do that any adjustment that is learned for the normal operation area will apply just as much to the entire engine operating range.
The Best you know, is the Best you've had........ not necessarily the Best.

wurk_truk

#203
THIS time around, I plan on using the Twin SCan and the NB O2s at the same time.   Last time, since I only had one pair of bungs, I used one and then the other on the same day.  I saw less than a 5% variance between v-tune and TS.  Until it came time to extend.  And there it basically appeared to me that the extensions were rich compared to the TS.

So, to answer Glens, yes I trust the Twin Scan, and I would imagine that yes, most trust the dyno.

And I equally can imagine where extensions are NOT rich compared to TS.  If someone uses a different method for OL sections of the bike...  shouldn't matter as long as the lower CL portions match up decently between the two tuning methods.

It's fair to say that folks like myself, Mayor, Stroker wonder where auto extend and blending does to the bike and its REAL needs.  Steve argues, and I really accept him at face value all of the time, but some of the arguing points make me wonder.  But here?  Steve has wholeheartedly agreed there is NOTHING wrong with a different tuning device for those areas that ACTUAL v-tune cannot cover.  In conversations in the past, v-tune is set up to TRY to be rich in those areas.  Tries to be is the key phrase.   If the OP, or myself, feel it's better to dial it in correctly using other methods....  nothing wrong with that, for sure.

The one place I differ with Steve a bit is how crappy broad bands really are and I beg to differ a bit on that.  They may be slower to react, but both use the exact same nernst cell technology, and if one takes TIME, like I SEEN Stroker do, for example, I feel the sniffing part is equal between the two O2 set ups.  Looking for O2 is what they do.

Now, though, lets deal with a source or two of friction between the O2 camps.  This is REALLY the basis of these continued arguments...  closed or not...   a LOT of this DOES come down to manufacturing differences.  DTT does NOT use the same math to derive the AFRs from O2 content as TTS does and my LM1s are different again.

Can ANYONE tell me the match used in Innovate products is faulty?  Nope.  How about DTT's math?  Nope.  TTS's math?  Nope.  So some of this isn't Steve saying his is better than everyone's else... well he does, but more to the point he gets passionate about HIS crap and HIS discoveries, etc.   It's like Dynos.  Dynojet makes the most cost effective dyno, so that it what we are all used to...  and the numbers that Dynojets MATH use to make numbers is ALWAYS higher than what the other, equally as good, dynes make.  The other Dynes use different math.

Right now, I am a homeless bum with a 120r sitting awaiting my pick-up in Cinci...  YAY!!!  It came in today!  But in a past life I was an electrical contractor.  Know how many engineer types I have dealt with?  EEs, MEs especially.  Steve is an engineering type of dude.  SOME of you members HAVE to get exactly what I mean, right?  I have had to AGRUE about jobs on WHY a 4" piece of PVC conduit will NOT fit in a 2x4 framed in wall.  Engineers!  HAHA!  But Steve is passionate and a true believer in what he sees.  One simply can't fault that, right?  I sure the hell don't and I sure don't believe it is in any way protecting his TTS franchise's money flow, either.  He actaully has called me to BS about little stupid crap he sees, OK?

Passionate Man, Steve Cole.

But, Jim Kennedy is EQUALLY as passionate on what HE does as a hobby.  Stroker is NOT a full time tuner and out to pump out bikes to support his shop and living.  It's a love for bikes, and love for working on them that made him decide to get a dyno and learn more.  Most members here can surely relate.  Once I am no longer a bum...  I, too, will own a dyno of some sort.  WE, and others see anomalies.  Well, what causes them and why are they there?  We ask.  We question.  We argue.  Steve does the exact same.  Whittlebeast should ALWAYS be allowed on here, for these very reasons... let Steve, et al, argue with HIM1  Right?  Did anybody here miss where we all learned how PV fills in fake data?  Of course not.  ARGUING a point with passion brings out more learning for all of us who care to learn, right?

But, Jim cannot be as equally as passionate on this site, it appears.  I have TOLD him to try to keep the BS in better check.  WHen I called Steve last year about him and Stroker...  no go I guess.  So, with Jim and Steve going at it, who do you, MY fellow members, think is going to 'win' with the Mods?

Steve, of course, to think otherwise is fairy tale thinking.

I HAVE seen Steve improve his online statements with Bob and Jim, but I now feel, since I want Bob and Jim's input and advice every bit as much as Steve's...  I hope Bob and Jim chill out a bit and present in more thought provoking fashions.  Especially Jim.   I LOVE Jim, he is a VERY good friend to me, more than  guys ever realize.  He is just hard headed like me... and Steve.  He just won't let PAST name calling and all that crap by ALL involved go by the wayside.  Well, I will talk to him this weekend, and I hope the Mod Crew takes MY advice and allows alternative thoughts and ideas have every bit as equal a voice on here.

Dammit...  this is THE BEST Harley engine forum going.  The free wheel style of the Mods make it so.  So, let him back and I will talk to him, and even Steve if needed.  No where else on the internet do we see an actual tuning MFG argue and teach, and no where else do we see opposing views come into play, and no where else do members get to benefit from these discussions more than us, the members here.
Oh No!

wurk_truk

And, for Glens, other tuning devices have capabilities that TTS may not.  No big deal at all.  Just like TTS will say what the command AFR is from the ECM.  Other tuners will state what the command AFR from the ECM is, and that number includes the trims.  Little differences that may be helpful.

Long ago, I had decided to trust ALL my tools, and use them according to their strong points.  Right now?  I have asked Jason, Hrdtl78, to help me understand EGTs better and maybe give advice on what metering systems he likes.  I have seen full blown data loggers for like $5-700 or simple meters...  What's best?  What has HE seen, right?

This post, by the OP, was about anomalies in AFVs.  I think we have alittle better undertsanding but not a whole lot.  AFVs are in the code, it is a stategy decided upon by a dude or a team.  To simply unquestionably accept someones code or scheme as 'right' with OUT questioning just isn't how I like to roll.

I'm every bit as passionate as the rest of you.
Oh No!

HV

Well said Wurk  :up: 
As mods we have a REAL hard time on here trying to keep the Name calling etc to a low point..after all not only are the Posters in this section ( more then most ) Passionate about their work we are dealing with Harley Riders . ( Can you say A Types ! ) ... we try to keep to the side as much as we can... I know a few feel this has become a TTS Board..and in some ways it has... not that we want it that way..its just that most questions are about that system ...is this an indication that most use it ? ... NO I know a lot that do not use a TTS Including myself... However Steve at least comes on and answers questions about his product ..Is the TTS the Best tuner ?  that depends who is using it ..I would literally suck at using one as I don't know that much about them or use them... I know a lot that use a SESPT and have very good luck with them.....as with the other systems its all about what the guy using it is comfortable using... I for one do not have the time to come on and answer SESPT Questions ..and the MOCO I'm sure could care less about HTT or the AFR Zone... I'm sure though that if more questions RE the SESPT were asked someone would do their best to answer... Jim is welcome back any time and I hope he continues as others to Talk about Tuning... Other Manufactures have been on here and off but are welcome any time to talk about their systems wile answering questions if they chose not to that's their choice ... The MOCO is not interested in any way in tech Support for the SESPT due to Warranty issues if a Customer re maps his bike and damages it...they hardly even show the dealers much about Anything other then Using the SESPT with a Dyno..... Smart tuning is a learn it yourself deal and I love it and find it works very well... perhaps the lack of questions on here about it is an indication that it works and does not have the issues a lot are having with the TTS..  :nix: :bike:
HV HTT Admin ..Ride Safe ...But Ride informed with HTT !!
Skype HV.HTT

glens

Quote from: wurk_truk on October 14, 2011, 01:33:54 PM
other tuning devices have capabilities that TTS may not.  No big deal at all.  Just like TTS will say what the command AFR is from the ECM.  Other tuners will state what the command AFR from the ECM is, and that number includes the trims.  Little differences that may be helpful.

Long ago, I had decided to trust ALL my tools, and use them according to their strong points.

Are you sure the TTS' "command AFR" doesn't include the trims when open-loop?  I don't know; just asking.

I agree that any tools used should be done according to their strong points, with others used for their strong points when there's overlap between the tools.  But the thought I was trying to convey was that if there's a discrepancy between two lambda readings and the one (main) "tool" is going to always use its reading, that'd be the one to go with.  Obviously, the ECM isn't going to be using its lambda probes to the right and bottom of the fueling tables, so it'd be okay to use a different one there.

I know I'd said this within the last month or so, and Steve followed with argument against it, but I can't find it right now.  Find out what the ECM is thinking it's doing just before it leaves closed-loop, sync up your external sensor with it there, then whatever the delta is between them, maintain it the rest of the way out.  No AFVs, either positive or negative, should then affect the AFR you want developed there.  (aha! the word "delta" should find the post; I'll try...)

Okay, I'd read it within the last month but it was posted within the last month or so a year ago!  Steve seemed to be arguing against it then, but didn't he say it'd be okay just a few posts back in this thread?  Oh well, at least I'm consistent, hahaha!

http://harleytechtalk.com/htt/index.php/topic,29246.msg300642.html#msg300642

At any rate, I'll eventually get around to doing something along those lines with my current setup.  I ordered the Fullsac x-pipe with both sets of bungs.

wurk_truk

I have tons of issues right now with life in general.  So, I am kinda lazy and havent gone out to look at the data from Datamaster, but...  TS does it for sure, ya know?  If I was going open loop, and I used v-tune and another device to do it with, I wouldn't care a whole lot about 'match up' between the tools.  But since we are talking CL, I would really pay attention to what BOTH tools had to say in the lower KPA and RPM ranges.  If I couldn't readily see a very close correlation between what BOTH tools are seeing, I would go out and find out why first.  I think Mayor has seen some issues where the bike has an issue where it toggles out of CL.  To combat that, I would think fixing other things on the bike, like exhaust, would have to come into play for best results.

I have tuned a closed loop tune using TS and TTS separately, and in combination.  When doing an AFR tune, I either like the TS or I use TTS without any clb bias while v-tuning.  Both allow me to play with CLB Bias tables and AFRs without having to re-tune upon each change.

Now with Lambda..  I really feel that my default will be v-tune for the reason given... use the O2s at hand that the ECM uses kinda thing, but... again,...  I feel limitations on the OL side of the tune.  Instead of extend, I would like to SEE what the engine comes out to actually want.  So... the tools need to match outputs 80 kpa and under for a good seamless transition, IMHO.

Glens, I like my Twin Scan + kit that I bought from Dr. V-Twin out in California.  I also have a pair of LM1s from Innovate, but haven't played with them at all.  A MAJOR question, one that gets asked often, is:  what is my AFR?  And... the real answer using v-tune and TTS is...  who knows.  As opposed to what you think I DO know about all of this...  I KNOW that for the whole TTS, v-tune, ECM thing... the AFR, or Lambda, value doesn't enter into it at all, really.  But it sure the heck should in open loop and it IS nice to at least check, see?

My next purchase will be an EGT gauge kinda set up.  I really wish to see the temp while tuning.
Oh No!

Steve Cole

The issue comes from the fact that the ECM uses information from the VE table even in both the closed loop mode and the open loop mode. So let take an example of how the ECM thinks, 3000 RPM and 80 kPa is where you are operating at. The ECM is not only using that VE point but also all those cells that surround it. So if your really at 3010 RPM and 81kPa and your in closed loop then when you get to 3005 RPM and 84kPa and your in open loop your using some of the same information. So now you set the VE table at 80kPa with an external sensor there but you just screwed up the setting for the closed loop adjustment at the same time. One need just to be careful and understand how it works prior to adjusting with an external sensor.

So if you let Vtune do the adjusting all the way to 82 kPa and you make sure that you have run the engine in all RPM zones to get the proper adjustments you have it tuned to what the ECM wants. Now those settings should not be changed. Now if you were to limit closed loop to 75 kPa and use external sensors to adjust the VE cells above 80 kPa one will not effect the other. Just remember the surrounding cells are being used so as long as you separate them you should not get into too much trouble.

What I argue with is trying to use the external sensor to tune the bike and then say that the ECM and factory sensor are wrong and cannot be used. So I guess it's all in how what you type gets understood. So you need to understand that when wurk_truk ran his test with external sensors things agreed within 5% but the simple true is we really do not know which one was truely correct, if either of them really were! The trick is to understand the only one that counts is the factory O2 and the ECM as that is what the decisions are going to be made on.

One major issue I have with Broad Band sensors is that very few if any of the current aftermarket systems have any way of testing them. I have seen many times a reading being taken on the dyno only to find out later it was off by over 1 AFR with them. None of the aftermarket systems are following the requirements as specified by the sensor manufacture. I brought this up and everyone says it doesn't happen only to find out that it does.  They need to be checked and replace and this is the same reason units that rely on them for the tuning have issues in the field. Yes, they are built from the same base technology but it has been found that they just do not hold up well on a HD or in racing environments in the field. The failure mode is that they drift the readings further and further away long before they fail completely. The worse I have personally seen was off by 1.5 AFR but I have been told by others they have seen them off by 2 AFR and still working. You have to buy test gas and check them from time to time and replace them when they begin to drift. True test gas will be labeled on the can as to what it is. So if the dyno operator doesn't have test gas or has something that is not labeled so that they can be check for accuracy use at your own risk or find a different dyno shop. Now if you are luck enough to find a shop with real Wide Bands those sensors get setup each and every time they get used and have to get a free air calibration and a full range calibration. If they will not set in, the sensor is going bad and you know it before you ever get started.
The Best you know, is the Best you've had........ not necessarily the Best.

glens

Quote from: wurk_truk on October 14, 2011, 06:12:27 PM
A MAJOR question, one that gets asked often, is:  what is my AFR?  And... the real answer using v-tune and TTS is...  who knows.  As opposed to what you think I DO know about all of this...  I KNOW that for the whole TTS, v-tune, ECM thing... the AFR, or Lambda, value doesn't enter into it at all, really.  But it sure the heck should in open loop and it IS nice to at least check, see?

To be sure, the one thing you most likely never will know is what your AFR actually is.  The best you'll be able to say authoritatively is what your lambda is.  I don't understand in the least why all these Dynojets, TwinScans, LM1s, etc. show "14.68" whenever the lambda is "1".  How can they possibly know anymore what the AFR might be?

I do agree with you that it's nice to know what's going down in the open-loop-only areas, but obviously any "AFR" number is going to be only some kind of relative thing these days and as far as I'm concerned its use ought to be relegated to the history books.  Lambda is lambda and that's all that matters.  And with properly set up equipment and VE tables on our current closed-loop Delphi EFI the AFVs will make sure the open-loop areas are always correct in that respect.  :)

wurk_truk

#210
Just bought a 4 channel EGT data logger.  I feel two for CHT and two for EGT.

HAHA...  6 bungs in the pipes.

Will use aircraft spark plug gasket sender for the CHT readings.

I agree on the 80 up kpa for the different tuner, whatever that may be.  Also, this is all about baselines.  If everything is set up right, like O2 placements, etc.  some of the pure tech terms we use like AFR, etc are a little bit fluid, I guess.  Tune with v-tune and see what that AFR or Lambda corresponds with on Datamaster, then one can check over 80 and get a good feel out of the results, right?

Glens, I WAS where you ARE as far as Lambda, etc.  Yes, it all sounds good, but I have been spanked by the best that it is NOT as simple as it all centers the lambda regardless of the fuel.  So... these guys will need to spank you, I guess, too.  :)
Oh No!

1FSTRK

Quote from: wurk_truk on October 14, 2011, 09:23:45 PM
Just bought a 4 channel EGT data logger.  I feel two for CHT and two for EGT.

HAHA...  6 bungs in the pipes.

Will use aircraft spark plug gasket sender for the CHT readings.



Oh no!
Now I’ll have to start a thread on which CHT sensor is right, the ones you added or the one the ECM uses. (Just kidding) The more good data collected the better. Then it comes down to how to interpret it and put it to good use. That is where this forum comes in, at times a fresh set of eyes and someone sees something we missed. I look forward to the day that you start to post what you gather from this set up as I feel it will help us all to learn something.

What 4 channel did you buy and where?

"Never hang on to a mistake just because you spent time or money making it."

1FSTRK

Quote from: wurk_truk on October 14, 2011, 09:23:45 PM

I agree on the 80 up kpa for the different tuner, whatever that may be.  Also, this is all about baselines.  If everything is set up right, like O2 placements, etc.  some of the pure tech terms we use like AFR, etc are a little bit fluid, I guess.  Tune with v-tune and see what that AFR or Lambda corresponds with on Datamaster, then one can check over 80 and get a good feel out of the results, right?


One of the things that this thread brought to light for me is that V-tuning and the rest of the VE tuning is not tuning the bike with the software. It is tuning the software to match the bike. Once that is done correctly the software tunes the bike and we can adjust the many offsets as we see fit. That is why both AFR and timing work off from MAP tables.   
If we look at AFR numbers the same as timing numbers they are just values in an equation. I’ve yet to see anyone set up sensors to confirm that a 32.5 number in the timing table actually triggers the spark at exactly 32.5 degrees BTDC. We all just work the timing by what the motor will take comfortably and move on. The same should be true with AFR and the entire range is base on what your ECM and O2 sensors see as 14.6 only because that value is the set point to activate closed loop. Everything above and below is a percentage higher or lower.
"Never hang on to a mistake just because you spent time or money making it."

glens

Quote from: wurk_truk on October 14, 2011, 09:23:45 PM
Glens, I WAS where you ARE as far as Lambda, etc.  Yes, it all sounds good, but I have been spanked by the best that it is NOT as simple as it all centers the lambda regardless of the fuel.

How could it possibly be any less simple than that?  The sensor's closed-loop system driving O2 to/from the backside of the cell so the difference across the cell mimics that of an NB sensor in a stoich burn environment has absolutely no idea whatsoever what the fuel composition or mixture could possibly be.  All it can do is create the appearance of a stoich burn and note what it took to get there (at the current temperature and pressure values at least, hahaha!) and report it.  If it takes no pumping of ions, the cell is in a stoichiometric burn environment; pump some ions in to get "there" and it's in a >1 lambda environment; pump some ions out to get "there" and it's in a <1 lambda environment.  (How can the relative pressures both sides of the cell not be extremely pertinent to any determination achieved by this closed-loop process?)

Oh, and let's indicate when we're at "lambda = 1.000" by saying we're at "14.68:1 AFR", even though there's absolutely no possible way we can know that...  (but if the operator wants to know what the actual AFR is, they can divide our display value by 14.68 and then multiply that by the stoich AFR of the fuel they happen to be using :)

Send the spanking crew.  I'd dearly love to hear how it's any different than that "in real life".

hrdtail78

"Then it comes down to how to interpret it and put it to good use."

There is a mouthfull.  I have looked into the equipment on spark and pressure in the cylinder.  I think that would be the kats azz for setting timing tables.  Too rich for me at this time.  I am looking at a dual channel EGT set up.  I can already see front CHT with datamaster.  The system can grow into a datalogger down the road.  I am interested to compare EGT, AF to exhaust pressure for best power.  But is all comes down to the above quote.
Semper Fi

Steve Cole

Do not confuse Cylinder Head Temperature with Engine Temperature they are not the same. CHT is the temperature of the head in the combustion chamber area, typically referred to right next to the spark plug. This is why they use a thermistor attached to the bottom sealing surface of the spark plug for most cylinder head measurements. While HD has the sensor in the front head it is far from reading CHT.
The Best you know, is the Best you've had........ not necessarily the Best.

rbabos

Personally have used both egt's and spark plug thermocouplers to check carb tunes on experimental aircraft engines. Frankly, I see no use for them with efi. If there's an acurate means of determining the afrs the exhaust will be within spec, as well as head temps. While it's all interesting to view, in the end it's overtooling for the task, and somewhat redundant. IMHO
Ron

glens

Quote from: Steve Cole on October 14, 2011, 06:28:21 PM
So if you let Vtune do the adjusting all the way to 82 kPa and you make sure that you have run the engine in all RPM zones to get the proper adjustments you have it tuned to what the ECM wants. Now those settings should not be changed. Now if you were to limit closed loop to 75 kPa and use external sensors to adjust the VE cells above 80 kPa one will not effect the other. Just remember the surrounding cells are being used so as long as you separate them you should not get into too much trouble.

The text I "bolded" is exactly pertinent to the underlying purpose of this thread.  So what you're saying is that we can decrease the closed-loop scope and cause the "outermost" AFVs to become "stranded" and no longer have an influence the rest of the way out, right?  Don't you think it'd be pertinent for us to be able to determine this stuff for sure, by knowing where the AFV cells exist in our current calibration?

wurk_truk

I know the MOCO sensor is NOT CHT.  Also, I didn't really buy the logger (innovate TC4) to be able to check only AFRs.  My thought is one from Russel...  Lonewolf.  Buy a PC3, set fueling tables all to zero, then play with timing and watch EGTs.  The PC3 allows changes on the fly and one can play with timing and not have to reload a new map for each change. Once one finds good happy timing, put it in the TTS map and load it up.

The Innovate logger has no gauge set.  Runs to the laptop.  I may buy a gauge set for it.  Maybe from Drew, who it looks to me, Dynojet used or got a license to use for PV.

Not sure.  THIS money, for new tools, is always aimed at the future, the more I learn now, the better I understand things.

I'm taking v-tuning to the extreme, HAHA.  NEXT tool will simply HAVE to be an old broke down Dyno.  If folks still use a dyno on HArleys ten years from now, that is where I like to see myself...  tuning.

But, I have LOTS to learn until then.
Oh No!

glens

Let me know when you get all set up.  I'll throw a case of beer in the tourpak and show up  :)

Steve Cole

Quote from: glens on October 15, 2011, 10:06:16 AM
Quote from: Steve Cole on October 14, 2011, 06:28:21 PM
So if you let Vtune do the adjusting all the way to 82 kPa and you make sure that you have run the engine in all RPM zones to get the proper adjustments you have it tuned to what the ECM wants. Now those settings should not be changed. Now if you were to limit closed loop to 75 kPa and use external sensors to adjust the VE cells above 80 kPa one will not effect the other. Just remember the surrounding cells are being used so as long as you separate them you should not get into too much trouble.

The text I "bolded" is exactly pertinent to the underlying purpose of this thread.  So what you're saying is that we can decrease the closed-loop scope and cause the "outermost" AFVs to become "stranded" and no longer have an influence the rest of the way out, right?  Don't you think it'd be pertinent for us to be able to determine this stuff for sure, by knowing where the AFV cells exist in our current calibration?

Nope didn't say that at all. What I did say was that if you use a secondary system to adjust ANY closed loop area and the ECM doesn't agree with it, the ECM will adjust it to what it wants. So now what you thought you set isn't what you ended up with due to the error in the systems. So be following what I said you will not have the issue as you stay out of any VE cells that are in closed loop when using the secondary system. So if the AFV and integrators are at zero adjustment they will stay that way once the closed loop tuning is finished.
The Best you know, is the Best you've had........ not necessarily the Best.

glens

I'd understood what you'd said before you brought up limiting the closed-loop coverage, and wanted to know if there was further significance to doing that (limiting C/L), otherwise why would you bring it up?

So if we limit the closed-loop area to 75kPa when it had gone to 80 in the base calibration, the applicable AFVs will still carry over to 80+ ?  Yes or no, please.

I'm just trying to make sure I've got a good grasp on what's going to happen if/when reducing closed-loop coverage takes place.  It's pretty pertinent to what this whole thread was all about.

Steve Cole

If you tune 80 kPa with secondary equipment it will affect the surrounding cells. So if you understand that part then the AFV's and integrators for the 75 kPa will be affected. So by tuning closed loop factory ECM and sensors to and including 80 kPa and only above that with the secondary system the two systems are not fighting over the 80 kPa cell. Now by cutting the Closed Loop area back to 75 kPa the AFV's and integrators will stop making any adjustment based on anything above 75 kPa. So now the two different methods of adjusting are not fighting one another.

You must account for all cases not just some of them as your question tries to do. It's not a matter of carrying the AFV and Integrator out to 80 kPa. If the AFV and Integrator are both "0" at 80 kPa this is what will be carried into open loop and by tuning 80 kPa in closed loop with the factory sensors it will stay that way.

The Best you know, is the Best you've had........ not necessarily the Best.

hrdtail78

Quote from: rbabos on October 15, 2011, 09:45:16 AM
Personally have used both egt's and spark plug thermocouplers to check carb tunes on experimental aircraft engines. Frankly, I see no use for them with efi. If there's an acurate means of determining the afrs the exhaust will be within spec, as well as head temps. While it's all interesting to view, in the end it's overtooling for the task, and somewhat redundant. IMHO
Ron

Besides just theorizing on that. I would rather do some particle test and reply later. I'm sure an EGT post is coming near future.

We have the same background dealing with this. Mine was more spinning a main rotor but....  Be interesting to say the least.
Semper Fi

wurk_truk

Quote from: glens on October 15, 2011, 12:17:39 PM
Let me know when you get all set up.  I'll throw a case of beer in the tourpak and show up  :)

That sounds cool as heck.  I WILL let ya know.
Oh No!