Husqvarna TR650 stupid fueling enhancement discussion

Discussion in 'Thumpers' started by TRZ Charlie, Aug 15, 2014.

  1. DeLewis

    DeLewis Been here awhile

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    I just bumped my AF-XIED up to setting 9 as well and it is fantastic - as you mention Jon, really strong throughout the rev range. The difference between stock and AF-XIED is almost night and day.
  2. roger 04 rt

    roger 04 rt Long timer

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    Glad that lambda-shifting is working out for you guys too. Here's a little more insight about what's going on.

    Below is a standard chart of Internal Combustion engine performance versus AFR (air fuel ratio). This particular chart came from Chevy. It's a chart that most piston-engine aircraft pilots know well because it helps us tune the engine, while cruising, for best power mixture.

    The line called Chemically Correct Mixture (CCM) (aka Stoichiometric) is at lambda=1, which is the same as saying 14.7:1 for gasoline (and is about 14.1:1 for fuel with 10% ethanol, which your ECU automatically creates by using Mixture Adaptation*). That line is the fueling set by your O2 sensor. That is an AFR where the amount of fuel and oxygen is in balance so that all the O2 and all the fuel can combine, so that no fuel or oxygen remains. However, not all the fuel and air combines in the engine. A bit of fuel isn't burned and a bit of O2 remains; and that fuel and oxygen combine inside the catalytic converter, which is why the cat gets hot.

    When you shift lambda, you move that CCM line to the left. As you do that you move the AFR toward the Best Operating Range or what pilots call Best Power Mixture (BPM) (where the plane flies fastest). As you start moving the line from CCM toward BPM, the engine usually runs smoother and the mixture ignites better. You don't usually have to move the line more than about halfway from CCM to BPM to feel an improvement in smoothness. This is what the LC-2 or AF-XIED do for you, and they do it in a way that works with the ECU, which is to say you don't have to remove the O2 sensor to add fuel, which preserves the ECU's ability to adapt to changing air and fuel conditions.

    [​IMG]

    * Mixture Adaptation: The same ECU process that knows to add 4% more fuel when you run gasoline with 10% ethanol also knows how to reduce fueling if you introduce a 4-6% Air Temperature error by changing the IAT sensor.
  3. jwdub

    jwdub Long timer Supporter

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    Good info on the AF-XIED settings. I left my Terra in WA when I came down to AZ for the winter -- I had the AF-XIED set at 7.5 and it was still exhibiting fueling issues. I also did the Pod Mod and canisterectomy just prior to leaving. Now, based upon more recent experience, I'm anxious to try it at 8 or 9.
  4. roger 04 rt

    roger 04 rt Long timer

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    Sorry you can't read the graph. It clearly shows that power increases from CCM to Best Power Mixture, which varies by engine.
  5. hasenpfeffer

    hasenpfeffer Been here awhile

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    What dedave is trying to not-so-eloquently suggest is that there has been posts that show the TR ECU fueling map is programmed to target a "rich" mixture at higher RPMs. He's suggesting that because of this, then the RPM agnostic nature of the O2 sensor spoofers can actually cause the bike to run on the downhill side to the left of Best Operating Range at higher RPMs, not the right side. The exact definition of the TR ECU's "rich" programming may be up to interpretation at this time.
  6. hasenpfeffer

    hasenpfeffer Been here awhile

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    Well that looks simple enough. :lol3:eek1
  7. TRZ Charlie

    TRZ Charlie That's MR. Asshole

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    Back off Dave.

    You have presented some good thought provoking ideas here. If you want to present a new idea that might benefit us all, and open it to discussion I encourage you to do just that. But dissing someone who brings a wealth of information as well as industry knowlegee to the table isn't going to help matters. Roger has been here to answer questions that many of us didn't know the answer to when we started. Roger has has been nothing but helpful in that regard.

    This is my thread, I started it and I would like to keep it civil. Got it? Back off.
  8. roger 04 rt

    roger 04 rt Long timer

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    Interesting questions HP

    I've seen opinions stated to this effect but no data. The afr plots from trz_charlie and big-t look pretty usual. During rapid throttle advance the ecu does two things: adds a temporary enrichment factor based on how fast you twist the throttle AND how much you twist the throttle. When at sustained wide throttle openings and high RPMs the base fuel map and long term fuel trim govern afr.

    There is no evidence that lambda-shifting of 6-8% causes high-load fueling to be "too" rich. Beyond that, the question of how rich is too rich is a good one. High power cruising wants to be in the vicinity of Best Power Mixture (BPM). Full power operation is often designed to be richer than BPM. This is done to slightly cool the combustion chamber to reduce the chance of detonation due to high temperatures and high pressures at full power.

    As an example, on takeoff an aircraft engine is fueled to full rich mixture until it reaches cruising altitude. Then for top cruising speed the throttle is reduced to 75% power and the mixture is LEANED to BPM. Sometimes it is further leaned to Best Economy Mixture. If the aircraft needs to climb at full power, the mixture is increased again to full rich.

    When you add 6-8% by lambda-shifting you are still 6-10% to the lean side of best power mixture. Lambda-shifting isn't about trying to create the very highest power engine it is about creating a smoother running engine.

    So how rich is too rich for the TR650, someone needs to measure and document it. But in the usual operational range a few percent more fuel is almost always beneficial to performance.
  9. DeLewis

    DeLewis Been here awhile

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    Hi Roger,

    I'm grateful for the abundant advice/info you continue to provide to this forum.

    I note from the graph supplied above that the best fuel mixture is in the vicinity of 13 to 1. According to the instructions provided with the AF-XIED, at maximum setting (11) the AFR target is 13.5. However, the instructions also recommend setting the AF-XIED between 14.3 and 13.8.

    The question would be, apart from increased fuel consumption, are there any other disadvantages to setting the device to maximum? As I am looking to maximise performance, I am inclined to try it out.

    There has been some speculation on this site and CH about the dangers of rich mixtures causing carbon buildup. However, it strikes me that new, fuel injected engines like the TR are vastly more fuel efficient than the older engines - yet I'm not aware of carbon buildup being a big issue with older / carburettor engines unless they are seriously out of tune.
  10. roger 04 rt

    roger 04 rt Long timer

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    Hi delewis, the actual point of best power mixture varies by engine. That said, I believe (and Steve Mullen at Nightrider does too) that you should only add enough fuel to improve the driveability of your ride. Many engines make improvements with as little as 4% more fuel, that's why many of us started with that amount. Some stay there, some add more fuel until they reach the point of diminishing returns. Big-t is satisfied with about 5% more fuel. Trz_charlie and some others are adding 6-8%.

    Here is one of my plugs after riding for more than a year with 6% more fuel. If you're concerned about carbon accumulation you can monitor it. What I've heard is that the worst in-cylinder buildups are caused by oil making it past the rings and valve stems.

    [​IMG]
  11. run-it

    run-it Adventurer

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    edit: unrelated ac stuff, nevermind : ^)
  12. roger 04 rt

    roger 04 rt Long timer

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    Exactly my point, most GA aircraft of my vintage (1980s) go richer than BPM for takeoff and climb (but cruise isn't richer than BPM). You are at high altitude and take-off is not necessarily full-rich but I didn't want to introduce that nuance into my description. For 7K feet density altitude, do you lean at take-off to a specified fuel-flow?

    Anyway, my point is that for short, full-power intervals, richer than BPM is not harmful and in fact is often the protocol.

    For motocycles, we're really talking about mixtures that are leaner than BPM.
  13. run-it

    run-it Adventurer

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    I (used to) lean to the rich side of a smooth running engine with no detectible rpm loss from best power during a static run-up for a simple a/c, high performance a/c I hit an exhaust gas temp (egt) target on the roll.

    Overly rich mixtures can cause rpm / power reduction, is it an issue on the TR with a shifter device? It may not be perfect but if it were bad I'd think someone would be able to feel it in their seat or otherwise show up in other tell-tale indicators.
  14. jwdub

    jwdub Long timer Supporter

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    Even if the Terra were to run over on the left side of BMP, realistically, how much time is spent at maximum throttle openings --- for me it's almost never and then it's very brief.
  15. run-it

    run-it Adventurer

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    Yeah the potentiometer / rheostat / variable resistor is vintage now, if you're cool with it then alright but I think most expect more even if it means paying more.

    Just an idea since you like keeping your original IAT, already spliced into wiring & don't mind the manual adjustments, you can build your own booster plug for cheap & throw your pot in the mix so that you can choose between BP or BP+ whatever value you want to dial up. BP = 56k resistor & 10k NTC thermistor in parrallel with each other then in series with your IAT.
  16. MarkHayward

    MarkHayward Adventurer

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    Thanks for the info, I will continue to play and maybe give fabricating a BP a try too.

    If the Potentiometer/VR is so vintage why are we not seeing more about it and posts giving info on best setting experience??
    Also why are guys still shelling out $$$$ for simple Resistance plugs which go inline with the stock AIT sensor - maybe they dont want to know ??
  17. roger 04 rt

    roger 04 rt Long timer

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    That's a good question. You can find a lot written about it, and which resistors riders experimented with including adding pots. The work was done 5-10 years ago. Search the Pelican Parts web site and you'll find it what was tried. I'm sure there are many such posts on various car and motorcycle forums. (Here's a link I found for you: http://forums.pelicanparts.com/bmw-...ture-sensor-improving-engine-performance.html.)

    Below is a clear chart showing what happened when I used a boosterplug and fuel pressure increase to add more that 15% to Open Loop fueling. You can see after riding for about a half hour, all the fuel that was added by the BP and the fuel pressure increase, was gone. The ECU uses the O2 setting as a reference, and learns how to correct the fueling to what the O2 sensor requires.

    No, my bike isn't a TR650, but TRZ_Charlie's bike shows that fueling of the Terra follows the O2 sensor. The best way to prove that what you're doing doesn't (or does) work is to install a Wideband sensor and measure the results. Why not try that?

    [​IMG]
  18. MarkHayward

    MarkHayward Adventurer

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    Roger as ever you are very informative and I value your opinion.
    However, my requirements, issues, experiments and observations are all Husqvarna TR650 Strada related and this bike and possibly its ECU map was not around 5-10 years ago.
    The information in the link is good and does show it is doable and so far for me it works.

    My statement and question was directed at the TR 650 Strada Owners that have fitted AIT Spoofers or experimented in a similar way that I have. Why is there not any more info on the experience and use of Variable Resistors from them?

    As far as I am concerned the best way for me to prove that what I am doing does or does not work is to ride the damn bike and see what happens.
    Having it all hooked up to wizardry and changing the stock sensor etc is not for me until somebody comes up with a real answer.
    Charlies bike may run great, but at what cost so far ???

    At this moment my bike also runs great and I can honestly say my latest mod cost me $1 and I am somewhat happy about that. Best of all any other owner can give it a try without upsetting the stock set up should they want to return to standard.

    Just one question, i understand all about the ECU trimmimg out the spoofer extra fuel inputs all based upon the Lambda readings, and this is shown in your graph, but please explain how there are so many guys out there who have not had the ECU learn so to speak. all of those in the Poll who state that their simple AIT sensor spoofer has not been rendered ineffective after 5000km???

    Thanks. MH
  19. roger 04 rt

    roger 04 rt Long timer

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    Charlie's cost so far is about $200, similar to other lambda-shifting options. He has a measurable permanent fix. I'm thinking of asking him to set up the same Mixture Adaptation (MA) experiment on his bike. That said, MA is a feature of every automotive EFI system that drives a catalytic converter for about 30 years. The MA strategies vary but have gotten more sophisticated year by year.

    As far as your second question, most experiments of the type you're asking about (do I feel better after ...) are designed as double-blind study, meaning that neither the tester nor the subject knows which bike is modified and which isn't. This is done to remove unconscious bias. Any individual doesn't need to do this, if they try something, and feel better, that's fine.

    I don't have a direct answer to your second question. But I can say that if there is an effect, it's other than air/fuel ratio.
  20. itsatdm

    itsatdm Long timer

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    Whether it is a real temperature or a "spoofed" temperature, the ECU seems to have the ability to provide a mixture close to stoich in closed loop, no matter what. I assume trim means, it is changing the amount of fuel provided?

    I don't understand just how the ECU can tell whether the temp is spoofed or a real one, unless it is comparing an AFR that is spoofed against an AFR that is programed to be no than X afr within the ECU.

    If that was the case, it would seem like none of these modifications would work.