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Thread: Ecotrons Engine Management

  1. #241
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    Quote Originally Posted by Nath88 View Post
    Quote Originally Posted by TZ350 View Post
    Unlike some other EFI systems the Ecotrons software does not allow for a binary input that switches between two maps. But there is a place for an analog input from the MAP sensor to influence the Ecotrons software to adjust the predicted fueling requirements from the Alpha-N map at any TPS/RPM.
    I was just about to recommend using the map switch I tried it out this weekend, its not dialled yet, but it's the best so far, I can roll along at 8500rpm and open and close the throttle as fast or slow as I like and it always responds. I will tune the main map by lambda feedback (it's pretty much done using values from before), and the misfire map by holding the engine at a load point, then holding the kill switch for a second or two, then release and judge the response when it comes back on as rich or lean, it should be instant and clean like a carb.
    The map switches when the peak pressure between 85 crank degrees and 125 crank degrees, measured at the PV vent (with an adjustable bleed to atmosphere) reaches 102kpa, atmosphere is 101kpa here.
    Means I'm confined to riding at sea level until I sort out a better implementation. Hoping the piezo pulse sensor will be the ticket, since it doesn't care about absolute values, If it works I'll make a bunch of them.

    I think the piezo on the cylinder head idea could work, if the signal is not too noisy.
    Between TZ and Nath88 we may yet see a practical DIY method for fuel injecting two strokes.
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  2. #242
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    Quote Originally Posted by Sandokan View Post
    would it be possible to somehow "record" an exhaust harmonic frequency in conjunction with a tps an wideband lambda on a carburated twostroke?
    Good idea Sandokan, I didn't record the exhaust but I guess its possible. I did use the wideband lambda and carb to get an idea of what the fuel map should look like.

    Quote Originally Posted by Niels Abildgaard View Post
    Put a Piezo thing ring under one of the headstud nuts or between head and sparkplug and a very rude instant cylinder pressure signal can be had.
    When piston is halfway down You will know if it fired or not. And then: Who tried it already and why does it not work?
    Another good idea, thanks Niels. It could well work, unfortunately my Ecotrons software does not have a suitable input available, it is short on alternative inputs. But it does expect a MAP sensor which is why I am trying to see what can be done with that.

    Unlike some other EFI systems the Ecotrons software does not allow for a binary input that switches between two maps. But there is a place for an analog input from the MAP sensor to influence the Ecotrons software to adjust the predicted fueling requirements from the Alpha-N map at any TPS/RPM.

    The Ecotrons software adjusts the injector pulse width according to the Alpha-N map and input from the MAP sensor. It is how to make use of that relationship for fuel injecting a two stroke which is the trick I am trying to learn.
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  3. #243
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    Attachment 332794

    Smoothed the MAP sensor reading by adding some volume by replacing the MAP sensor hose with a small chamber.

    Attachment 332793

    MAP sensor Yellow line. Interesting that the line on the left as the engine is still winding down and zero throttle is higher than the MAP pressure line at WOT and as the RPM starts to rise again.
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  4. #244
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    Quote Originally Posted by Nath88 View Post
    Same rpm, same throttle position, different airflow. The pipe effect on a misfire is very weak if it exists at all...

    Attachment 332725

    My graph doesn't show this well, but above 7k RPM the on-pipe and off-pipe air flow is too different, the on-pipe fuelling (what you've tuned for) will not support combustion off-pipe. Way too rich, true lambda probably around 0.5 or worse. As the engine speed falls below 7k rpm, the on-pipe and off-pipe air flow is not so different, true lambda is approaching the rich limit until it supports combustion. Once combustion begins the small increase of airflow from the pipe effect will bring the lambda above the rich limit, 'clearing' the cylinder. You could install any old MAF sensor to prove this.

    I'm still working on the Ion sensing, but I'm getting impatient so I'm going back to measuring the pressure at the PV vent since that worked the best so far (I now have an adjustable bleed to atmosphere so I can adjust it's sensitivity), and using that input to try a table switching approach. Have a fuel table for no-pipe effect, and a fuel table that incorporates pipe effect. Theoretically I could put a box-style muffler on and tune 1 table, then put the expansion chamber on and tune the other. Pressure pulses will determine whether the pipe effect is active and ECU switches between the tables accordingly. Away from the pipe's effective rpm the tables should be more and more the same.

    I'm thinking a box-muffler would provide no scavenging effect, and no return wave effect, can someone confirm that?

    I'm also designing a 'pressure pulse' sensor. It's basically a piezo electric microphone hooked up to exhaust pressure, it will more accurately and quickly detect the exhaust pulse from the cylinder than the pressure sensor. I figure I can hear when the engine is firing clear as day, why not use a microphone...
    Quote Originally Posted by Nath88 View Post
    Same rpm, same throttle position, different airflow.

    Attachment 332725
    I understand Nath88's explanation for the change in the LamW02 trace Yellow line. .... good one.

    Attachment 332825

    Pressure in the exhaust header pipe as measured by a MAP sensor, Yellow line, RPM Blue line, LamWo2 Brown line.

    Through a one way valve arrangement the MAP sensor only measures the high positive pressures of the returning pulse in the header and does not see the negative suction pressure.

    Interesting that the MAP pressure line on the left as the engine is still winding down and at zero throttle is higher than ambient and the MAP pressure line on the right at WOT which starts at ambient before obviously rising again as the engine gets on the pipe. There is quite a sudden drop in MAP pressure (Yellow line) when the throttle (Red line) goes from fully closed to fully open.

    But why does the header pipe positive pressure behave like this? ...... .. high and above ambient when there is no throttle and the engine is winding down then goes lower when it's on WOT and starting to pick up again.

    Quote Originally Posted by Nath88 View Post
    I saw something similar with mine.
    Since we're measuring the peak, it implies the average pressure in the pipe must be lower than atmospheric by a fair bit?
    Has anyone witnessed a vacuum in the pipe at any time?

    Once the engine starts making power the exhaust flow creates pressure in the pipe due to the stinger restriction.

    A differential pressure sensor with the average pipe pressure as the reference might be the go. Or my new sensor, should be testing the prototype next week.
    Attachment 332827

    Can you set the crank angle for sampling the MAP sensor with the ecotrons?
    Quote Originally Posted by Grumph View Post
    Can I suggest that the whole system - from inlet via crankcase to muffler - has one end closed when the throttle is shut and the chamber tailpipe is then doing what it's supposed to and acting as a pressure bleed resistor. Open the other end to atmosphere - open the throttle - and the system pressure should drop to atm and possibly lower momentarily.
    That is possible I guess, but on overrun with throttle closed and the motor not firing what could be creating the pressure in the pipe?

    You would think any residual pressure from a full power run would have bleed away quite quickly but on other graphs it actually looks like it builds up a bit.

    Bit of a puzzle

    Quote Originally Posted by Nath88 View Post
    Can you set the crank angle for sampling the MAP sensor with the Ecotrons?
    No. But I am very interested in the sensor you are developing.

    Quote Originally Posted by Nath88 View Post
    That's a shame, timing will be key for this thing.

    I thought that it was showing atmospheric pressure off the throttle, going into vacuum as you opened the throttle. What pressure is atmo?
    But if its producing positive pressure with a closed throttle I'm out of ideas... Definitely qualifies as a puzzle.
    Quote Originally Posted by Frits Overmars View Post
    Pipe pressure varies not only with throttle and rpm, it can also vary locally because of wave superposition.

    It might be instructive to experiment with several pressure take-off points along the pipe.

    Attachment 332834
    Yes I can see how wave superposition can create a localized high pressure spot although I would expect the node to move with frequency as the RPM dropped. I will look for that next time.

    Quote Originally Posted by teriks View Post
    Assuming that the one way valve is working properly, and you still have that bleed between the one way valve and sensor, the lowest pressure you should ever see at the sensor is atmospheric, no matter how low the pressure in the pipe is.
    Yes, that is how I read it too.

    Quote Originally Posted by teriks View Post
    ... the drop in pressure when opening the throttle:
    Closed throttle => ~0 airflow thru the header
    Open throttle (even without firing) => >0 airflow the the header.

    Now, depending on the geometry around your pressure pickup position its not at all unlikely that the pressure drops in that position simply due to flow. -Think venturi..
    The closed throttle no flow pressure was higher than atmospheric and dropped to atmospheric when the throttle was opened again. Your venturie idea is interesting.

    Pressure node and venturie effect could explain it.......

    Attachment 332835

    Quote Originally Posted by Nath88 View Post
    I was just about to recommend using the map switch I tried it out this weekend, its not dialled yet, but it's the best so far, I can roll along at 8500rpm and open and close the throttle as fast or slow as I like and it always responds. I will tune the main map by lambda feedback (it's pretty much done using values from before), and the misfire map by holding the engine at a load point, then holding the kill switch for a second or two, then release and judge the response when it comes back on as rich or lean, it should be instant and clean like a carb.
    The map switches when the peak pressure between 85 crank degrees and 125 crank degrees, measured at the PV vent (with an adjustable bleed to atmosphere) reaches 102kpa, atmosphere is 101kpa here.
    Means I'm confined to riding at sea level until I sort out a better implementation. Hoping the piezo pulse sensor will be the ticket, since it doesn't care about absolute values, If it works I'll make a bunch of them.
    Attachment 332861

    Just realised/remembered that the ecotrons EFI system does have a switch for switching between two maps. I had been using it for so long as an input for the wide band O2 sensor that I had forgotten about it.

    But after I have got the on the pipe map sorted it looks like I may be able to use one of your switches to then develop an off pipe or miss fire map.

    The performance switch just switches in another table of values that are used to divide the values in the main map. Ie if you have a load value of 120 in the Alpha-N map and switch in the performance map that has a Lambda value of 0.85 then the Alpha-N map gets divided by 0.85, 120/0.85 = 142 ie the result is a richer mixture for exceleration.

    I guess there is no reason why the performance switch can't be used to lean the Alpha-N map off when the engine has misfired or is off the pipe.

    Quote Originally Posted by Nath88 View Post
    If it's another TPSxRPM table with multipliers it should work great. I'm doing the same thing right now but in a spreadsheet, then dropping the numbers into the tuning software. The multiplier is the pipe effect on airflow so it's a more sensible value to use anyway. You'll need to extrapolate the tuned 'firing' map you have into the skip-fire/misfire regions as best you can. Making the switched input to feed into the ECU will be the hard part, but I want to do that for my setup as well to free up the MAP input, and make the sensor unit a plug and play product for any ECU.

    Had a play with the piezo disc for the exhaust pulse sensor, looks promising, very sensitive, minimal noise, nice.
    Quote Originally Posted by Nath88 View Post
    If it's another TPSxRPM table with multipliers it should work great. I'm doing the same thing right now but in a spreadsheet, then dropping the numbers into the tuning software. The multiplier is the pipe effect on airflow so it's a more sensible value to use anyway.

    Had a play with the piezo disc for the exhaust pulse sensor, looks promising, very sensitive, minimal noise, nice.
    Yes that piezo looks promising as the basis for a switch. I will definitely be a customer for one.

    Attachment 332883

    This is the Ecotrons EFI softwares Basic 16x12 Alpha-N map.

    Attachment 332884

    When the "Performance" switch is activated the corresponding cells in this 16x12 map are used to divide their related values in the original Alpha-N map to give an alternative fueling value.

    This seriously looks like it could be used in the way you have described previously of leaning the fuel off when there is less air flow when there is no pipe action drawing air through the motor.
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  5. #245
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    Quote Originally Posted by wobbly View Post
    Quote Originally Posted by TZ350 View Post
    Another unfulfilling and downright frustrating experience with Ecotrons support Dept.... .
    Did it occur to you TeeZee that just possibly, you know more about the system now, than they do.
    With small capacity high performance 2T EFI that maybe true ... ... and sure, in fairness you can't expect them to be onto everything.

    But what I asked for was a simple change to a basic cal file to turn on the LamO2 sensor. I want my cal file to have both "Injection Angle End" and "LamWO2" options.

    Its easy enough, other EFI software packages come with tick box's for that sort of thing. With Ecotrons you have to enlist their assistance and it is often a slow difficult negative experience dealing with their help dept.
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  6. #246
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    I received a reply from Ecotrons lastnight. The advanced calibration file needs these changes to be able to monitor and record results from the wide band oxygen sensor.

    CV_SSFLAM = 4
    CV_SSWO2 = 1
    VAL_uLamSlope = 0.3
    VAL_uLamOfs = 0.5

    Hopefully I will get to try it out this afternoon.

    I used to think that it was easier for the local 2T Kawasaki 350 and Yam 250 that are successfully running EFI because they did not rev much past 9,000 and so only needed one logical injector and that the bigger capacity helped mask fueling miss steps.

    I started to have doubts about that when I saw that some small 2T drone aero engines 25cc or less were successfully running EFI. But these basically run at a constant speed.

    The issue for me is drivability, i.e. throttling off for a corner and then on again exiting. After Nath88 pointed out that you can have two different air flows through the engine due to pipe action/non action for the same Throttle/Rpm position on the Alpha-N EFI fueling map and remembering Frits's explanation of how the wave action in a pipe collapses when throttling off and how it takes some time to re establish after throttling on again.

    I now think that one of the big differences is how aggressive the pipe is. On a small capacity high performance race engine the pipe action in drawing air through the engine would be much more variable than the pipe action on a larger capacity MX or Trail bike engine setup more for power range and usability than outright power hit.

    So in getting 2T EFI to work, it turns out the pipe makes a huge difference, who would have thought ......
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  7. #247
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    Quote Originally Posted by TZ350 View Post
    I received a reply from Ecotrons lastnight. The advanced calibration file needs these changes to be able to monitor and record results from the wide band oxygen sensor.

    CV_SSFLAM = 4
    CV_SSWO2 = 1
    VAL_uLamSlope = 0.3
    VAL_uLamOfs = 0.5

    Hopefully I will get to try it out this afternoon.

    I used to think that it was easier for the local 2T Kawasaki 350 and Yam 250 that are successfully running EFI because they did not rev much past 9,000 and so only needed one logical injector and that the bigger capacity helped mask fueling miss steps.

    I started to have doubts about that when I saw that some small 2T drone aero engines 25cc or less were successfully running EFI. But these basically run at a constant speed.

    The issue for me is drivability, i.e. throttling off for a corner and then on again exiting. After Nath88 pointed out that you can have two different air flows through the engine due to pipe action/non action for the same Throttle/Rpm position on the Alpha-N EFI fueling map and remembering Frits's explanation of how the wave action in a pipe collapses when throttling off and how it takes some time to re establish after throttling on again.

    I now think that one of the big differences is how aggressive the pipe is. On a small capacity high performance race engine the pipe action in drawing air through the engine would be much more variable than the pipe action on a larger capacity MX or Trail bike engine setup more for power range and usability than outright power hit.

    So in getting 2T EFI to work, it turns out the pipe makes a huge difference, who would have thought ......
    Maybe the bang bang set up.
    https://www.pressreader.com/australi...82050504983923
    More research required...

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