Power Commander V w/Autotune Discussion

[jammess]

If you want a richer mixture look into Innovate Motor Sports wideband O2 sensor with LC-2 controller available on Amazon pretty reasonable. You can then connect a laptop to the LC-2 via USB port and select virtually any AFR you want. I use the LC-2 on my two oilheads with an AFR of 12.9:1 which results in smoother idle and no detectable surging. I went with 12.9:1 because hot rod tuners consider this to be the lean best power AFR, I concur. Also results in noticeably more low end torque and performance. The wideband O2 sensor takes the place of your narrow band sensor and the ECU won't know the difference. I assume the FJR has one O2 sensor ahead of the catalytic converter? If not that presents a problem. Oh, with the LC-2 you can run a realtime recording of your AFR ratio as the bike runs to verify operation.

I would like to see someone with an FJR try this. If I had an FJR I would. Knowing Yamaha I bet the later FJR generation bikes don't surge or run lean anyway. Yamaha seems to have a good rep when it comes to listening to their customers unlike some manufacturers who shall remain nameless.

 

[ajpagosa]

If you want a richer mixture look into Innovate Motor Sports wideband O2 sensor with LC-2 controller available on Amazon pretty reasonable. You can then connect a laptop to the LC-2 via USB port and select virtually any AFR you want. I use the LC-2 on my two oilheads with an AFR of 12.9:1 which results in smoother idle and no detectable surging. I went with 12.9:1 because hot rod tuners consider this to be the lean best power AFR, I concur. Also results in noticeably more low end torque and performance. The wideband O2 sensor takes the place of your narrow band sensor and the ECU won't know the difference. I assume the FJR has one O2 sensor ahead of the catalytic converter? If not that presents a problem. Oh, with the LC-2 you can run a realtime recording of your AFR ratio as the bike runs to verify operation.
I would like to see someone with an FJR try this. If I had an FJR I would. Knowing Yamaha I bet the later FJR generation bikes don't surge or run lean anyway. Yamaha seems to have a good rep when it comes to listening to their customers unlike some manufacturers who shall remain nameless.

There's a guy over on Advrider who has done some pretty cool stuff with the LC-2 with oilhead BMW's, RogerRT I think is his name. I think he sells a kit, did you get one of his? I like the data acquisition capability. I had already purchased a PC3 + wideband for my oilhead GS and was very pleased with it otherwise I may have gone that route instead. You are right, it eliminates a lot of the surging issues with the GS. I run it at 13.5 AFR at the moment with no further issues, and I had plenty before. The PC3+WB has the extra capability of entering a base map somewhat like the ordinary PC3. Roger has done some amazing work using the LC2 + DA in decoding what the GS factory ECU is doing. Maybe somebody needs to do that with the FJR. I nominate Mr Canoehead.

But to the FJR, I do not think the surging issues on it are the same source as the on the oilhead, as richening it up does not eliminate it, whereas doing that on an oilhead pretty much kills it, with the LC2 or with the PC3WB. Flat air-cooled twin vs water cooled inline 4. Furthermore the PCV + AT200 is a much more flexible wideband system (in principle) as you can target more than just one AFR, a whole bunch of them in fact, and a range/limit of trim adjustments.

Let me put it this way. Setting the PCV + AT200 up with a wide trim limit and one target AFR in all cells should easily replicate the LC-2 function, outside of data acq. It is a closed loop wideband system after all. I've done that a few times over the years and it doesn't work very well at least on my bike, but I was using DJ base maps (001/002) which are very rich in the 20-70 area. But that just highlights the mystery, a closed loop wideband system set up right should cure a lot of problems but it doesn't, at least not on my bike at altitude.

By the way using the zero map and setting up the PCV + AT as I did above was basically an attempt to set it up like an LC2 (really more like the PC3WB). I was eliminating the fuel map variable and just concentrating on the wideband function. The fact that the AT cannot adjust past the trim limit means it was not working the way I had hoped, but it is still encouraging. I had no surging issues at all or stumbles even using the 20% limit. I plan to continue playing with that as well as trying what the DJ guy suggested regarding zeroing out the 20-70 AFR quadrant.

It may be that the thing I was doing with the zero map allowed the AT to compensate for ECU dithering and still stay within allowable AFR range, whereas starting off with an aggressive base map will not. Thinking out loud here while typing (dangerous) if you had say 13.0 target AFR and +/-20 trim limits, working off a base map that was already very rich, you could easily dither your way past the 11.5 threshold and get stuck there per above comments from DJ. But if your base map was just zeros, you would find that a lot harder, even starting with same target. Hmmm.

I do not like the idea of killing off the AT200's ability to adjust fuel in a large quadrant where I do most of my riding, mainly due to the fact that as much elevation changes a typical ride I go on is really going to mess with an open-loop system (which is what it would be with the AT off in that quadrant). Maybe one thing to try is a hybrid, still using the full AFR table but only a zero fuel map in that quadrant, to let the AT still do its thing there, but off of zero and not something so rich.

One last thought. My understanding of the LC2 on a GS is it only works in the region where the factory ECU is operating in closed loop. Or more precisely where the factory non-WB O2 sensor would be operating closed loop. You basically graft a WB O2 sensor onto the factory system with some simple signal conditioning to scale voltages etc. On an FJR the closed loop operation of the factory ECU is that 20-70 range described above, only about 1/4 of the full rpm-throttle region. Here is a sample PC3WB map for BMW GS, gray area is closed loop for factory ECU and the only place the wideband works. Assume LC2 is similar

 

[sath182]

AJ, can you post your target AFR table?

Sure, here it is. I copied/pasted it out of the OTS Dynojet FJR map 001/002 (same table):

Interesting - that is much richer than I was aiming for...I was going from 13.8 down to 13. Looks like DJ is aiming for 13.2 everywhere except where you are cruising (where they aim for 13.6)

Where they have 13.6 as the target, they are targeting a balance between power and economy. The regions that are mostly 13.2 are really only used during acceleration so they are tuned a bit fatter to put more focus on power.

Also the AFR, or FAR in this example, is directly related to the speed of the flame front. More fuel giving a faster burn during higher RPM/throttle loads. Which is further affected by the ignition timing management used throughout the rev range.

 

[ajpagosa]

Well if you go back to post #18, look at map 001, and compare to the AFR table I posted above (also from map 001), you'll see some interesting stuff.

Namely that Yamaha ECU was running far leaner in the lower throttle, lower rpm/throttle % range (judging by how much fuel the 001 map adds) and much richer in the higher throttle areas (judging by how much fuel the 001 map takes out) to hit the AFR's in the table. Indicating that the Yamaha ECU went way richer under accel and way leaner at cruise, or at least does so in open loop mode with the O2 sensor disconnected.

Anyway theory is one thing, reality another, and implementation trumps both. In our case (gen 2 FJR) it looks like the main thing plaguing us might be the dithering the ECU does in its (formerly) closed loop operation area, combined with the DJ/AT quirks leading to poor drivability. The actual tenths of a point of AFR in the target table either way I suspect has little to do with anything substantive yet. IOW I bet you could slap say 13.5 into every cell in the AFR table and not notice much change seat of the pants or smoothness, except maybe fuel economy.

However, like I did recently, starting from base map of all zeros, that was a huge improvement in seat of the pants, smoothness, and drivability because it for whatever reason got around the implementation issues of the (possibly) too aggressive DJ maps + Yamaha ECU's closed-loop-area dithering + AT cross-talk with all of it. Is it optimal for power/economy? Who knows, I doubt it. But neither is much of a concern if it is unridable.

 

[Mr_Canoehead]

RogerRT proved that on the BMW (Bosch Motronic) ECU, changing the O2 sensor with an LC-2 or with a XFied fooler in the closed loop range made a mixture difference throughout the RPM range as the ECU extrapolated the changes across all mapped cells. It doesn't appear that the Yamaha ECU is as sophisticated. Based on what I have read, the O2 sensor only affects the closed loop mode and there is no extrapolation of adaptive cell data in the ECU. I have also read that the Yamaha ECU doesn't save adaptive adjustments but I have seen behavior to make me think that this isn't true.

Thanks, AJ for the nomination on the LC-2, I do have one sitting on the shelf and have thought about trying it for mapping/shifting. If I were retired, like AJ and RogerRT, I would definitely give it a shot. Given that work keeps encroaching on my riding time, I would rather get the AT working properly - it should be a better solution for the FJR.

I have definitely been aiming leaner than 13.2, so that would be a good place to start. I think my next step is to apply the 13.2/13.6 targets and then back it off a little and see where the surging/drivability issues start.

 

[ajpagosa]

RogerRT proved that on the BMW (Bosch Motronic) ECU, changing the O2 sensor with an LC-2 or with a XFied fooler in the closed loop range made a mixture difference throughout the RPM range as the ECU extrapolated the changes across all mapped cells. It doesn't appear that the Yamaha ECU is as sophisticated. Based on what I have read, the O2 sensor only affects the closed loop mode and there is no extrapolation of adaptive cell data in the ECU. I have also read that the Yamaha ECU doesn't save adaptive adjustments but I have seen behavior to make me think that this isn't true.
Thanks, AJ for the nomination on the LC-2, I do have one sitting on the shelf and have thought about trying it for mapping/shifting. If I were retired, like AJ and RogerRT, I would definitely give it a shot. Given that work keeps encroaching on my riding time, I would rather get the AT working properly - it should be a better solution for the FJR.

I have definitely been aiming leaner than 13.2, so that would be a good place to start. I think my next step is to apply the 13.2/13.6 targets and then back it off a little and see where the surging/drivability issues start.

Hey Mr C.,

Now I remember. You are correct, Roger found that the BMW Motronic ECU still uses the O2 sensor input even in open loop mode. So even with a scaled, tweaked wideband input it is still working and if you scale it the right way you can spoof it to richen or lean out the AFR, you just can't target an AFR in that area in closed loop. I actually would be surprised to find the Yamaha ECU did not behave this way with a properly set up LC2. This fact (using the OEM O2 sensor input in open loop) was one of the downsides to the PC3WB on the GS, as it does not use the factory O2 wiring into the ECU, it goes directly into the PC3. So the WB sensor cannot affect open loop area off the shaded gray in the above map. But you can program all the map cells as with any PC3. That is IIRC, being so old and retired

However I get back to PCV + AT. It covers the entire rpm/throttle grid closed loop so in principle it should be able to work better than any open loop or partially closed loop system, once we get over this dithering and associated issues. It sure would be nice to have a painless way to collect data off the FJR.

AJ

 

[Mr_Canoehead]

However I get back to PCV + AT. It covers the entire rpm/throttle grid closed loop so in principle it should be able to work better than any open loop or partially closed loop system, once we get over this dithering and associated issues. It sure would be nice to have a painless way to collect data off the FJR.
AJ

Maybe something like the Dynojet POD-300 would be good for logging results?

 

[ajpagosa]

However I get back to PCV + AT. It covers the entire rpm/throttle grid closed loop so in principle it should be able to work better than any open loop or partially closed loop system, once we get over this dithering and associated issues. It sure would be nice to have a painless way to collect data off the FJR.
AJ

Maybe something like the Dynojet POD-300 would be good for logging results?

I've seen that but not done any research on how easy it is to use, what it can log, memory, ease of use, etc. Was bummed to find out LCD200 was not very well executed.

 

[jammess]

Actually Roger04 is the guy that got me interested in the wideband sensor to cure surging on my '04RT about 4 years ago with the LC-1. The LC-2 is also a great data logging device as well. I can see exactly when the Motronic ECU goes closed loop and by attaching my laptop to the passenger seat I can go for a ride and plot fueling data. Really a valuable tool. I switched to the LC-2 because wiring was much cleaner and the LC-2 is more stable than the LC-1. I gave my LC-1 to a guy in Texas to cure a surging problem on his R1100RT. The 1100 oilheads had it worse than the 1150 bikes I know because I also have a '93 R1100RSL. If I get an FJR I will part with the RT but the RSL is a keeper with only 7K original miles and all put on by me.

I have definetely decided on the new 6 speed FJR.

 

[sath182]

email to dynojet.
Pasting this here to save, not clear if it went through using their website. I cannot find the old tech support email contact I've used previously. They just have a web form now and it is not very user friendly. There is a phone number for tech support I'll try later.

What contact email did you end up using, BTW? I wanted to send in some questions specific to my SVs' auto-tune settings.

 

[ajpagosa]

email to dynojet.
Pasting this here to save, not clear if it went through using their website. I cannot find the old tech support email contact I've used previously. They just have a web form now and it is not very user friendly. There is a phone number for tech support I'll try later.

What contact email did you end up using, BTW? I wanted to send in some questions specific to my SVs' auto-tune settings.

I ended up using the web form here

https://www.powercommander.com/powercommander/Contact/powercommander_sales_support.aspx

I tried emailing back to the email address from which the guy responded but never heard from him again.

I must say after thinking on this for a few days I am disappointed to be told the solution to my difficulties with AT is to essentially turn it off in the area where I do most of my riding. Fortunately the zero map thing seems to be working well and I'm going to try another trick this weekend. Basically taking the OTS DJ map (which is too aggressive and otherwise causes problems), cut all the values in the fuel map in half, and set AT to +/-10%. This will have the benefit of populating the cells with moderate values in the areas I can't seem to fill in, and then restrict AT adjustments to something reasonable that may not get it stuck in a loop on up to one mile elevation changes on a typical ride. And of course allow the AT to target trims in the entire range.

One thing that became clear from discussing this with the two DJ reps, the cell values in a given fuel map are actually tenths of a point of AFR. This is never made clear in any DJ literature I've ever read but it makes sense. Eg a value of +10 in a fuel map would take an AFR from 14 to 13. They often say it is a % richer (or leaner) but that never made any sense to me.

 

[sath182]

email to dynojet.
Pasting this here to save, not clear if it went through using their website. I cannot find the old tech support email contact I've used previously. They just have a web form now and it is not very user friendly. There is a phone number for tech support I'll try later.

What contact email did you end up using, BTW? I wanted to send in some questions specific to my SVs' auto-tune settings.

I ended up using the web form here

https://www.powercommander.com/powercommander/Contact/powercommander_sales_support.aspx

I tried emailing back to the email address from which the guy responded but never heard from him again.

I must say after thinking on this for a few days I am disappointed to be told the solution to my difficulties with AT is to essentially turn it off in the area where I do most of my riding. Fortunately the zero map thing seems to be working well and I'm going to try another trick this weekend. Basically taking the OTS DJ map (which is too aggressive and otherwise causes problems), cut all the values in the fuel map in half, and set AT to +/-10%. This will have the benefit of populating the cells with moderate values in the areas I can't seem to fill in, and then restrict AT adjustments to something reasonable that may not get it stuck in a loop on up to one mile elevation changes on a typical ride. And of course allow the AT to target trims in the entire range.

One thing that became clear from discussing this with the two DJ reps, the cell values in a given fuel map are actually tenths of a point of AFR. This is never made clear in any DJ literature I've ever read but it makes sense. Eg a value of +10 in a fuel map would take an AFR from 14 to 13. They often say it is a % richer (or leaner) but that never made any sense to me.

Thanks, that's the same form I had settled on using.

I wonder if the dithering is encountered only in cruising conditions or if it's also present when rolling straight through the rev range like they recommend...

That last bit is really interesting. I think it only applies to the main map though. I noticed that the adjustments on the trim table are not directly translated to the main map. I can't quite remember the numbers of an example off the top of my head, but it's not a 1:1 adjustment (especially on the enleanment trims). Picture you have a +20 on a cell in the main map. And the trim adjustment says -13. You would expect to come out with +7 after accepting the trims, but actually end up with something like +12.

I"m gonna look for a nice open stretch of road this weekend and work on my trim tables by doing a series of pulls in 2nd or 3rd gear. Before I do that though, I need to make reference marks on my throttle grip for the percentages. Thank you, companion software, for making that incredibly easy. Too bad I don't have data logging so I can see what the measured AFR is for some of the trouble cells I'm keeping my eye on.

 

[sath182]

I had sent my email yesterday morning, BTW, but hadn't received a response yet this morning. (Which is why I that's why i asked.) Well I just got it while typing that last post. I'm a little disappointed in the answer.


Here's what I'd asked:

I have a few questions about setting up the auto tune trim table for my 2009 SV650SF. I recently came across your video about operating the auto tune functions in the desktop software. In it, the Tech recommends zeroing all of the 2% as well as the 5% throttle columns up to 5k RPM due to exhaust reversion. My bike is currently equipped with a full M4 exhaust system and a K&N air filter, PCV, and Auto Tune. No other performance mods are in place.


Here's my questions:
Since the bike being demoed in the video is an I4 sports bike, is there a different RPM/throttle range I should be aware of for reversion based trim errors?

Is there a way of effectively tuning these portions later that doesn't require professional help?

Separately, I use a lot of engine braking in my riding. Lately, I've been trying to make sure that this is all on completely closed throttle since i have the 2% column zeroed. Would this type of condition have any negative effects on the tuning?

Aaaaaand the reply:

You can use the same exact guidelines discussed in the video.


You shouldn't need to tune deceleration ranges of the map file at all, unless you are trying to reduce or eliminate deceleration popping. In that case, you would just add or subtract fuel manually in the deceleration range of the chart until a desireable effect is achieved.

I know it's not completely applicable to the FJR, but any effects of engine braking on the trim table would be interesting to know about. Seems like I got a canned answer that didn't address my questions. :upset: Especially #2 which is actually directly applicable to your concerns with the closed loop section of the FJR map. Maybe I'll have to try calling as well.

 

[ajpagosa]

I had not noticed as large a discrepancy in the trims vs corrected fuel maps after trims had been applied. But I will look for it. I just checked the zero maps and trims that I ran, when applied there were only couple of cells in the fuel map different from the trims, and those were only off by 1. Trim and fuel are integer only, whereas AFR has one decimal place. I figured the diff was due to rounding but maybe not. There has to be some logic related to capping trims applied to fuel maps, as some cells are going to be closer to max or min duty cycle than others.

I think you re right about engine braking, I was trying to raise related issues with the guy on the phone, about ascending and descending large elevation changes at similar throttle positions and how different fueling would be vs load but he didn't seem to think it was an issue. "AT will take care of it". Then of course next guy says "turn off AT".

 

[ajpagosa]

Short update. Loaded up the 50% 001 map (1/2 the cell values in the fuel map from DJ OTS 001) and went for a quick 50 mile ride, elevation from low of 7200 to 12k ft and back. AT trim limits were +/-10%, same AFR target table as 001/002. Had typical stumble off idle prior to warm up but this is common with a new map. Minor surging after warm up which went away quickly as things adapted. Good news is it pulled like a freight train all the way to redline in 2nd and 3rd gears, very strong. This is subjective but I do not remember a 2/3 pull this strong ever before, like the bike is shedding you off the handlebars if you don't hang on (at ~9k ft no less). Very obviously better than the zero map in this regard. I'm assuming this is because it had better values in the higher throttle/rpm cells where zero map just had zeros, and the AT200 could get to where it needed to go. I plan do do a much longer ride (300+ miles) with this map soon and worry about inspecting trims after that. This was just a shakedown run to see if it was doing anything bad and it didn't.

I am beginning to feel confident that the issues I've had with my bike and the PCV + AT were due to the base DJ maps just being too aggressive for my altitude & typical ride's altitude deltas, and/or the trim limits used combined with the dithering allowed the unit to get into a bad spot which it just could not adapt out of. Of course we don't know what the ECU is actually doing, but it seems to me a good path to go is be conservative on the fuel map and trim limits, and leave the AT on all the time to compensate for altitude AND any dithering the sneaky ECU is messing around with.

I'll post up a trim table after that longer ride.

 

[ajpagosa]

Update here. Got a nice 400 mile ride in yesterday. Still running the 50% map above, half the values of the DJ PCV 001 FJR map. AT on, +/-10% trim limits. AFR target table same as previosuly, from OTS DJ maps 001/002. Have not saved any trims yet, so this is still working off the pristine 50% base map. Bike ran flawlessly, no hiccups surges or stumbles. Very strong. Conditions were somewhat extreme, very hot 95-99 deg F indicated on dash display. Multiple high passes (10-12k ft ASL), steep grades, lots of traffic and quick passes of slower tourist vehicles up and down slope.

Loop was Pagosa Springs to Lake City, Montrose, Ouray, Silverton, Durango, home to PS. Indicated 398 miles. Temps early AM were low 50's, rapidly rising to just under 100 deg by say 11 AM.

Here's the trim table from that ride. Note how much more of the table has been filled in, all the way out to 100% throttle in some cells. More later:

 

[ajpagosa]

Comments on the above ride, map, and PCV + AT.

1. This was exactly the kind of ride that previously would have the bike running progressively worse, limping home nearly unridable. In fact it is over much the same route & elevations that caused these problems before.

2. Subjectively I am very pleased with the way the bike is running now. So much so that the ride above started off as a 100 mile early-morning shakedown run at lower altitude, as I knew how hot it would be, and then I was having so much fun I just kept going.

3. Going out on a limb maybe here, but I think if you have an 06/07 that has displayed many or all the well-documented throttle jerkiness, lean surging, stalling, flat spots etc. etc. that these are known for, and you've gone to a PCV to "fix" them, then if you are running some of the more aggressive maps (001/002 or even some of the "smoothness" maps) at high altitude, you'e going to have problems. If you've got an AT also and running +/-20% trim limits on top of those maps at altitude you're going to have problems.

4. Revisiting what we've got here. Running a PCV + AT there are 3 distinct systems determining fuel.

a. First is the (open loop) Yamaha ECU. It is running open loop because the factory O2 sensor is gone. It is a simple speed-density system at this point, calculating fuel based on TPS, temp, ambient and MAP sensors, no load input or AFR feedback at all. Basically another look up table guessing at mixture beacuse there's no O2 sensor. You are NOT supposed to run the DJ O2 emulator plug (I know I've tried it and it sucks). Even with O2 sensor disconnected and running open loop, there is a (formerly) closed loop area of the ECU operation (up to 7k rpms and 20% throttle) which still dithers mixture for various reasons. No one knows how much dithering takes place, how often, what AFR range etc.

b. Then there is the PCV running whatever base map has been downloaded. This also runs open loop, on top of and in series with whatever the open-loop ECU is doing, and adds or subtracts a % of fuel to whatever the ECU wanted. Note that during a dithering cycle it will amplify the dithering effect. Suppose the dithering is +/-10% and you're cruising along in a cell that the PCV map already wants to add 20% to. At the midpoint of dithering (zero IOW) you're running 20% richer. At the peak rich of dithering you're running +10% + 20% (+32%), at the valley -10% +20% (+8%). The percents multiply (1.1 x 1.2 = 1.32 = +32%)

c. Now add the AT200 on top of these two open loop systems in series. This is closed loop on a wideband O2 sensor, but the loop closes around the PCV's output and AFTER the Yamaha ECU produces its output. There is no input into the ECU from the PCV or AT200. Point here is the closed loop works on the PCV not the ECU, so the AT200 is going to try to hit AFR targets after the dithering has taken place from the ECU, and after the PCV has amplified it. So the AT is trying to undo amplified dithering to hit AFR targets, within constraints of user-defined trim limits.

d. Now add high altitude to this. 12k ft ASL air density is something like just under 9 PSI vs 14.7 at sea level. At 6k ft it is ~12 PSI. So reduction of over 25% air density going from 6 to 12k ft (typical ride for me) and an increase of over 33% going the other way. Meaning fueling needs to adjust somehow the same amount as air density for AFR to stay constant under same throttle/load scenarios. It is not unreasonable to think given this with amplified dithering, large AT trim limits, and an aggressive base map that bad things can happen. We already know from DJ that out of range AFR readings will cause the AT to stop working in that cell. Not clear if it goes into a default mode or what. Also not beyond reason that the ECU running open loop gets stuck in some parameter hole also. And....don't forget DJ maps were created on a dyno roughly at sea level, so at 12k ft air is nearly 40% less dense than where these maps were created, meaning (open loop) stock ECU would have to lean them out this much for a PCV without AT to run right. I don't even know if that is possible.

All of the above plus recent good experiences withe the 50% map lead me to the following conjecture. For my location and riding constraints, the PCV +AT is best used in the following manner: conservative base map + conservative trim limits, AT on all the time (to undo all the stuff the open loop ECU is doing and the PCV is amplifying) running the wideband O2 sensor in closed loop. I never liked the advice to turn it off after adapting, just the base PCV with no AT on always ran poorly on my bike. I had hoped the AT would fix that but it may be the fix is not in iterating in on the "perfect" base map (there likely isn't one for all altitudes) and then leaving AT off. It may be the perfect map is a conservative one somewhere in the middle of where your typcial ride's cells would be, that lets the AT do its thing closed loop all the time above and below to compensate for dithering and altitude, but constrained to not fall into parameter holes or bad AFR's for either/both ECU or AT200 (or whatever it is that made the bike run progressively worse and worse over time).

After all, in my experience at least, nobody turns off their aftermarket wideband closed loop O2 system on hot rods and various other highly modded engines. You'd never, ever run open loop AFR's on a highly boosted car for example, precise control of AFR is the gold standard in performance and not blowing stuff up. I don't see why the same wouldn't apply to a quirky high performance motor like the FJR's. The trick is to set it up right without actually knowing WTF is going on inside that open loop stock ECU. This is where some real time data acq would be nice.

 

[ajpagosa]

Been having a very productive discussion off line with another long-suffering gen 2 FJR + PCV + AT victim, Mr. Canoehead. What we were trying to figure out, among many things, was how fast the AT works to update AFR and trims table values, and whether it is targeting AFR directly in real time, or it has to have a trim table value and then adjusts fuel off of that (and not the O2 sensor directly). So I volunteered to do some simple tests, which were made obvious by our discussion.

Short answer is, it doesn't matter as both are done pretty fast. What I did was set up a zero fuel map (0's all cells), with 13.0 AFR table in all cells, +/-25% trim adjust limits, zero'd out all trims. Warmed up the bike and ran it on the center stand at idle and 2k rpms, watching how fast the AFR changed, inspecting trim tables and doing various other things.

Here's two emails that describe exactly what I did and what was learned:

======================================================================================

Subject: some results

OK did some quick tests, very interesting results.

Looks like the following happens. AT adjusts trims very quickly AND saves them to the trim table. Here is what I did.

1. Set up a zero fuel map (for later), set AFR table to 13.0 all cells.

2. Warmed bike up with a 5 mile or so ride, old map from my weekend ride. Came home, shut it off. Loaded the new zero/13.0 map. Set warm up time to 60 seconds (down from 300) for convenience.

3. Test 1: started bike, at idle (900 or so RPMs) AFR read mid low 12's. After 60 seconds AFR immediately began climbing to 13.0 and stayed there, randomly oscillating around 13.0 approx 1/10th a point or less. I let it idle there for approx 1 minute. Then I revved up light throttle to apprx 2k RPM and held it. Same behavior except now it started higher AFR (14-ish) and dropped immediately (couple seconds) to 13.0 and oscillated there. Inspecting trim table trims had been updated either + or - to hit target AFR.

4. Test 2: Here I thought maybe in previous test the AFR could be targeting 13.0 immediately but the trims taking longer to adapt. So I after clearing trim table I repeated the test except this time instead of letting it sit at idle or 2k rpm for a minute, the moment I saw it hit 13.0 on the display I revved to 2k, then the moment I saw it hit 13.0 there I turned the bike off. Inspected the trims, they'd been updated to same or similar values as test 1.

I will repeat these tests and do some more testing. But it seems that both the AFR's and the trim tables are getting updated very quickly, so it may be moot whether it is using the trim table to adjust fuel, or it is using the target AFR table and only updating trim table.

Next I will run it as is (starting with a cleared trim table) let it adapt to 13.0, then change the target AFR table to 13.5 and send that map, see how long it takes to show 13.5 on the display. I'd also like to see what happens if I restrict trim to say 10% but make the target AFR outside what it can get to.

More later.

=============

This is starting to get interesting. I repeated the first two tests, same results.

Then I did the following.

1. Cleared the trim table, but then restricted trim limits from +/-25 to +/-5. Sent map, still at all AFR targets at 13.0, started up. After 1 minute again the trims began to adjust quickly in the direction of 13.0, but could not get there. The trim limits were preventing it. Let it run for a minute at idle and a minute at 2k rpm. Neither could get to 13.0, at idel from 12 it could barely get to 12.5, at 2k down from 14 barely hit 13.5/13.6. So we can discard what one DJ guy said, trim limit does cap AFR adjustments.

2. Then I set trim limits back to 25, started up, 1 minute, let it adapt to 13.0 AFR at idle and 2k. With the bike still running pulled map and inspected trim tables, same as prior iterations. Idle leaned out 2k richened up to hit 13.0. Then without turning anything off, I edited AFR target table to 12.5 AFR. Sent map to the PCV while idling, immediately, faster than it adapted to 13.0 (which was already fast like 2 seconds or less), it dropped right down to 12.5. Then revving and holding at 2k rpm, same thing. Dropped right down to 12.5 maybe a tiny bit slower than at idle, but maybe a bit faster than initially moving to 13.0 from nothing. Then I inspected the trim tables and they had been updated richer or leaner than 13.0 to reflect targeting 12.5 AFR in rpm/throttle cells where I'd been running it.

Also one thing I noticed on all these simple tests. It is hard to hit exactly a single %/rpm cell. One or two neighboring cells were also updated, but less than the cell closest to where the bike was running. So some kind of weighted updating is going on, if you are at say 900 rpm at idle, it will update the 1k cell more than the 750 rpm one. Both it will update both. Similar with # throttle.

So conclusions.

1. I think it is targeting AFR subject to trim limits and updating trim table and AFR about as fast as it can. I am not sure it matters if it is waiting for trim table to be updated, or it targets AFR in real time and updating trim table but not using it. Whatever it is it is fast, or at least far faster than I had feared. It may not be fast enough however to do true real time closed loop AFR esp if the actual AFR is far from the target. Which is why it would be good to get a base map somewhere in the middle of where typical riding happens, and leave the AT on with maybe restricted trim limits, to be able to have best chance of hitting target under different conditions.

2. It may not be updating fast enough during a pull or rapid throttle inputs. It would be hard to do this in a garage but could certainly be done out on the road. Do say 2 somewhat identical pulls, then do 5, then 10. Inspect tables see if anything was updated. I suppose I could blip the throttle out to 5k rpms a few times in a garage to see if anything changes, or if it can hit the target while revving. We'd need some data acq to do this right.

Anyway good stuff. I am relieved to find it adapts as fast as it does, it seems unlikely that the AT itself is falling into a "parameter hole" as I had feared. However it may be the case that a sudden big throttle input is too fast for it and there's a stumble. However it should adapt back out towards target AFR after far less than a second, so something else was going on when my bike would run so poorly, and progressively worse over time.

What we are not able to see here is what the underlying open loop ECU is doing, the dithering or whatever look up table it is employing, and how the AT reacts to that. The AT should be fast enough to offset all that given what these tests show though I can still see how the 3 systems combined might get into conflict.

 

[ajpagosa]

One other important conclusion from the above testing session, but not so much the testing itself,the warm up ride prior:

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When I went out for a warm up ride using the map from the long weekend ride, I paid very close attention to how the bike worked at light throttle and lower speeds, say under 45 mph, before the AT turned on. This was just around my neighborhood for 5 miles or so. I have been running with the AT timer set to 300 seconds, and that was still set.

As it was warming up, it was stumbling and surging a bit on the tiniest of inputs, and at steady throttle, nothing huge but annoying. By the time the temp gauge had risen to full warm it was still doing that but 5 min had not passed yet. As it passed 5 min (by the dash clock) boom, all that went away and it got very smooth, so that cracking the throttle no stumble or surge and it felt 100% better.

Conclusion: ECU is running in pure OEM open loop mode + PCV base map and having all these issues even after warming up for a few minutes (no AT yet, so no trims being applied or trim table adjustments made, but 50% of 001 base map values are being applied). The moment the AT turns on it all goes away. That was of course with my prior map, trim table, etc. exactly as I parked it from that long ride.

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And furthermore EVERY DJ map, from PC3 days to PCV (without AT) had these issues virtually all the time. This would mean ECU + PC 3/5 running in series both open loop. But here they go away literally immediately when the AT starts up running closed loop. So the direction from DJ tech support of adapting a map and then shutting AT off, or blanking out AT in 20% & 7k rpm cell block (where most riding is done!!!) is not helpful at all. At least not with a gen 2 FJR that exhibits the suite of well-known problems.

 

[sath182]

I wonder if I can reproduce results like this on the SV. I might be able to accomplish that if I force it to run poorly just off idle using the map. Then see how it reacts after the AT turns on. It sure would ease my mind regarding the massive tune changes that keep showing up there.