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Meinolf

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Posts posted by Meinolf

  1. Hi,

     

    In other words, if CO trim >zero

     

    not really.

     

    The CO trim changes injection time. The ECU uses the following formula t = (value x multiplier)  x 64.5µs. The multiplier, thats a value stored at $B7B3 in the BIN, extends from 0% to 200% ($0-$FF).

     

    Assuming the multiplier value in your BIN is 1 ($80), the CO trim value would be t = (value x 100%) x 64.5µs. Then the following formula can be used to calculate Lambda.

     

    λnew = (λcurrent x (base map value + CO trim value)) / base map value

     

    But that's theory. In reality you will not know what the base map value is at which the engine is currently running. So you need to measure anyway.

     

    Cheers

    Meinolf

  2. Hi Roy,

     

    this probably needs some background explanations.

     

    The 15M is an alpha-n type ECU. That just means that TPS angle (alpha) and rpm (n) are used to determine breakpoints in tables in which values are stored which translate into the opening time of the injectors, which determines the amount of fuel injected. Plus plenty of correction factors, partly in  tables and partly as scalars.

     

    The basic equation looks like this: Injection time = (Fuel map value + cold start value) x n correction factors.

     

    There's one base map which contains the values for the left cylinder and an offset map, which contains the delta, as plus/minus values, for the right cylinder.

     

    At the time the 15M was launched no tools existed to download the content of the ECU (=BIN), which is a mixture of program code and data. In fact the ECU code doesn't even support downloading of its content. Beard, the author of GuzziDiag, devised and used a method to get to the data nevertheless. Which, btw, is the reason why the download of a BIN takes ~15min and uploading only a couple of seconds,

     

    Now, as with any device an engine is the sum of components, each of which will have tolerances. Adding the tolerances will result in deviations. Now add external circumstances such as air temp/pressure, quality of the fuel, legal requirements for emissions and noise different from country to country, wear of components over time, and so on. The BIN and its values should cover all of this.

     

    It's obvious that such a BIN is not tailor-suited to any specific engine. If the tolerances even out then it might be perfect or close to it, but that's rarely the case.

     

    So the vendors needed methods of adjusting the values to a specific bike and found 2 methods, One is CO trim and the other one are the bypass screws,

     

    CO is equivalent to AFR. So adjusting the CO trim changes the injection time which influences the AFR. On the 15M this can be done with GuzziDiag. The trim values, the range is -127 to +128, are added to be base map values. At low TPS/rpm the base map values are lower than at high TPS/rpm. Adding 1 (CO trim) to 10 (base value) equals 110%. If the base value is 100 then the percentage change is 101%, That's why changing the CO trim has less impact at higher TPS/rpm settings than at lower ones.

     

    The bypass screw has the same effect. But instead of changing the injection duration and thus the amount of fuel it opens a path for air to enter. The main differences are that the CO trim affects both injectors/cylinders, the bypass screw only one cylinder and the CO trim is a quantified change, the bypass screw is not (unless you take # of turns as precise quantity)

     

    The instrument used for measuring can be a CO tester, I use a AFR logger from Innovate, the LM-2. As the CO trim changes the injection duration of both injectors measuring CO at the tailpipe is ok. On the 15M the CO trim can be changed with GuzziDiag and other programs,

     

    As to the value to aim for, that's an interesting question. What do you want to achieve? If it's just the value required by law, take that. Otherwise it get's a bit more complicated. There are some basic correlations between λ, power, emissions and efficiency. Bypassing the emissions, a λ of 0.86 gives best power, a λ of 1.05 gives best efficiency,

     

    I have BINs where I targeted λ 0.88 in all areas, that is all of the 256 breakpoints I could reach while logging, and others which are more sophisticated. See here https://db.tt/zptc3hQB

     

    The Guzzi engines, in my experience, idles well at any λ from 0.7-0.98.

     

    Cheers

    Meinolf

  3. Hi Docc,

     

    The *theory* at the time was to "trick" the ECU to enrichen the AFR throughout the range. For reasons that are (more) obvious now, it didn't work, especially at low throttle openings.

     

    the thought is correct, AFR will be impacted.

     

    But whether the result is a rich or leaner mixture depends on the actual values in the fuel map. I found that Guzzis are very forgiving in regards to rich mixture. During my experiments I had extended areas where Lambda was at 06.-0.7. I didn't feel it when riding. Lean conditions, on the other side, are very much noticeable. Any time Lambda exceeds 1.0 the bike gets jumpy.

     

    In this case using the CO trim setting would be the prefered - but not best - approach. The CO trim adds a constant value to the injection time, whose influence will be biggest at low fuel values and decrease with bigger fuel values. The best approach is to measure AFR and adjust the fuel values to achieve the desired AFR.

     

    Cheers

    Meinolf

  4. Hi,

     

    I don't think we differ in opinion by much 6 mV over 5 Volts is only 0.12%, you will not be able to set the TPS that accurately. The TPS is only one part of the equation, engine speed, oil temperature, air temperature, atmospheric pressure, battery Voltage also figure into it, I'm sure I missed a few.

     

    and again I completely  agree. It's a small difference, and the resolution of the AD makes it seem even smaller and less important. And who knows the the accuracy of the AD? And not everybody will be using a hi-quality DMM to measure and set the voltage. And the TPS tends to slip a bit when fastening the screws. And....

     

    BUT, why not use the value we know to be correct and try to get as close as possible?

     

    Cheers

    Meinolf

  5. Hi,

     

    is the 150mV (156 according to Meinolf) with the throttle fully closed.

     

    it's not really according to Meinolf, but according to the curve of the TPS used, PF03C. The formula of the PF03C for voltage dependent on opening is mV = (degree x 105) / 150. If this is changed to Degree = (mV-150) /105, it's easy to see that the calculated degree value will be

     

    As the voltage resolution of the 8bit AD is 0.01953V (5V/256), the first voltage value step bigger than 150mV is the 8th (8 x 0,01953 = 0.15624V). So the cell $07 contains 0 degrees as value, the cell $08 0.06 degrees and so on. So this is were the 156mV come from.

     

    As the values in the original TPS lookup table, in all the BINs I have seen, are slightly off, here's a recalculated and correct one (for PF03C): https://db.tt/bhegzYG1

     

    Cheers

    Meinolf

  6. Hi,

     

    I have been reading the setting of the TPS thread along with all of these posts and I see where you back the RH idle screw all the way off but I am not seeing where you adjust it back in? 

     

    the right and left hand idle stop screws are used to adjust the idle speed and synch the cylinders at idle after the TPS base setting was done.

     

     

     Also, If I don't have the dig software is this futile for me to attempt?

     

    You don't need GuzziDiag to adjust the TPS. The granularity of the 8bit AD in the ECU is not good enough to use GuzziDiag to set the voltage to 156mV. A DMM is needed for the purpose.

     

    Cheers

    Meinolf

  7. Hi,

     

    The air bleed screws have a slight effect on mixture at idle because you can change the idle speed without changing the throttle angle.

     
    I fully agree. The adjustment procedure using the bypass screws stems from the time when the BIN couldn't be modified. The best approach is to keep the bypass screws completely closed and adjust the mixture by changing the values in both fuel maps based on logged data. Which has the beneficial side effect of making good BINs transportable to other bikes as the unquantifiable influence of the bypass screws is avoided.

     

    The white knob sets the throttle balance under power, has anyone tried to do that on the move?

    Yes, that's my SOP when checking the synchronization after having made significant changes to the BIN. It's a bit awkward, but can be done if the road is empty and straight.

     

     

    The way I interpret the 150 mV setting it's just a reference point like the survey mark down the street. The bike never operates there but as Meinolf pointed out it anchors it to the map the same as a surveyor would reference the marker before laying out the foundations.

    It's 156mV, not 150mV. That's a 4% difference and you do feel the effect. The air flow at low throttle openings is a very turbulent one and getting the mixture right and stable at low throttle settings is really time consuming. I've spent 50% or more of the entire logging focusing on the 5% breakpoints at low rpm and TPS opening.

     

     

    I wish people would forget about 530mV, it means nothing, just set the idle at 1100 or anywhere else you want it to idle. personally I find 1100 too fast, it takes away from the engine breaking. Last time I did my EV I just used the fast idle lever.

    Again, completely agree. I found an idle of 900rpm with a completely cold engine right after starting, which increases to a rock-solid 1000rpm at any other air or engine temperature to be high enough to provide sufficient oil pressure even if the engine is cooking and also charge the battery sufficiently.

     

    To increase engine breaking I also added fuel cut-off at the lowest three TPS break point columns down to 2700rpm. Which is not essential for the Jackal, but very helpful with the V11 if driven spiritedly.

     

    Cheers

    Meinolf

     

  8. Hi,

     

    for some time now I have been looking into the function of the 15M ECU. Over time this expanded to sensors, actuators and other peripherals having impact on the gas flow and mixture and then more and more deep dives into the theoretical background.The 15M has lots of potential, even though it's quite simple compared to the current generation of ECUs.

     

    My initial approach was to change the fuel maps based  on road data logged with a LM-2. But that quickly turned out to be a short-sighted one, as this is just scratching the surface. So I built this ECU simulator https://db.tt/G7pXsKEx and started a systematic research, trying to reverse engineer the unknown functions of the multitude of tables and scalars in the ECU code. All of the findings are applied to the BINs I use for road testing and logging in my V11 and now a Jackal as well. I have also shared my BINs with several members here and on Wildguzzi, the general feedback was good even though BINs optimized for a specific bike leave much less room for deviations than the original BINs.

     

    In short, the findings so far are that all! trim tables in the BIN identified so far are lacking. Neither air nor engine temperature or the barometric correction were correct and the TPS look-up table contains wrong values. The impact of the individual settings on AFR is usually quite small, but errors add up. So one percent here and two percent there can add up to the mixture being off by 10 or 20 percent in the end, and that's noticeable. As many have experienced yourself, looking at the problems reported here.

     

    So a laid back approach to getting the base settings right, replacing sensors with resistors, changing the CO trim or twiddling the bypass screws results in just that, a laid back performance.

     

    Cheers

    Meinolf

  9. Hi,

     

    The closest I got to a 150 without backing off the idle right hand idle screw or disconnecting the sync rod was 159. 

     

    then you are making a mistake.

     

    Setting the TPS to 156mV (not 150mV) with all rods disconnected and both throttle stops fully out is key. The ECU code contains a 16x16 lookup table, which converts the voltage coming from the TPS to degrees. The cell $08 in the lookup table contains the 0 degrees, the voltage corresponding to that opening is 156mV. If you don't get this right then all values depending on the TPS opening (fuel, acceleration, ignition,...) will be off target and the ECUs uses the wrong values. That is, values don't match to the actual opening.

     

    That is most noticeable at low openings, because the free cross sectional area of the intake increases following a cosine function. That means that a low openings, say going from 1° to 2°, a small change results in a much bigger free area changes than at large openings. Below is a sample calculation for a Jackal, which has a smaller bore than the V11, but the relationship respectively the %-changes are the same.

     

    TPS angle alpha (break points) Athrottlevalve Cross section area of throttle valve [mm^2] Aflow Cross section (Throttle body - Throttle valve) [mm^2] open cross section (Throttle body - Throttle valve) % change versus previous TPS break point 1 1235 22 1,7%   2 1213 44 3,5% 50% 4,05 1168 89 7,1% 49% 4,6 1156 101 8,0% 88% 5,33 1140 117 9,3% 86% 6,3 1119 138 11,0% 85% 7,54 1092 165 13,1% 84% 9,01 1060 197 15,7% 84% 10,85 1020 237 18,8% 83% 13,43 965 292 23,2% 81% 16,93 891 366 29,1% 80% 21,53 795 461 36,7% 79% 28,15 664 593 47,2% 78% 37,03 500 757 60,2% 78% 48,28 319 938 74,6% 81% 60,93 158 1098 87,4% 85% 84,8 267 989 78,7% 111% 90 262 995 79,2% 99%

     

    Hm, the paste and copy of the above table didn't work. A simple formula to calculate the cross sectional area is:

     

    A = (3.14 x D2 / 4) x (1- (cos alpha / cos alpha0)), where alpha is the opening angle and alpha0 is the angle with the butterfly closed. If you are interested, here: http://www.diva-portal.org/smash/get/diva2:23184/fulltext01is one source for the calculation. Page 13, 3.1.2.

     

    The opening at idle is not critical. It will be what results out of setting the required idle speed with both cylinders synchronized carefully.

     

    Cheers

    Meinolf

  10. Hi,

     

    IF you have the means to measure AFR then forget the fiddling with the bypass screws. Close both completely, sync and set idle speed with both throttle stops (left and right) and set the right mixture at the break points in the BIN. This eliminates the random flow of air thru the bypass screws at idle and higher rpm. If perfection and transportability of a BIN between different bikes is the target, then the CO trim should be at 0.

     

    and if you have AFR logging at your disposal, then go the full stretch and use the corrected trim tables I have published elsewhere for engine temperature, air temperature and barometric pressure. Else you will be tuning the fuel map values to one specific situation ONLY. AFR will change significantly overall and differently between cylinders if this is not done. Also change the TPS breakpoints, at least the smallest one, to coincide with the actual TPS setting at idle. My recommendation is to change several others (in the range of 6-13°) as well.

     

    The ones I am using are 0.99, 3.31, 4.23, 5.15, 6.44, 7.54, 9.38, 10.85, 13.43, 16.93, 21.53, 28.15, 37,03, 48.28, 60.93, 84.84.

     

    0.99° is the TPS setting at idle speed on my bike. Which, with syncing via throttle stops (at idle) and correct fuel values at that break point results in an idle of 900rpm after start (cold engine) and a rock-steady 1000rpm at any temperature once warmed up. The Lambda I have choosen as target (and set) at idle is 0.92 and identical for both cylinders.

     

    The results are worth the effort. And make BINs much more interchangeable between different bikes with the same set-up.

     

    Cheers

    Meinolf

    • Like 1
  11. Hi,

     

    the following explains why the adjustment procedure including TPS setting is the way it is.

     

    The ECU only sees what is send to it by external sensors. These are the TPS (and several others). TPS only provides data about the right throttle valve. The ECU code contains several tables which provide the translation from voltage to degrees (in case of the TPS). The value for fully closed throttle in this table is 157mV (not 150mV). So that's the value you set the TPS to when everything is disconnected.

     

    The value after reconnecting the linkage doesn't have to be 525mV. It can be 500 or 400mV. The ECU will interpolate anyway (unless you follow below procedure, then your idle setting is exactly at a break point). Set it so the specific bike idles best. 

     

    The 8bit A/D of the ECU sees voltage in steps of 0.0195V. If the TPS base line is set wrong, the ECU sees the opening of the throttle different from where it actually is. This means that values from a different break points are used in the multitude of tables it uses to select and calculate injection duration, ignition, ....

     

    The rest of the sync procedure just aligns the left cylinder to the right.

     

    IF you have the means to measure AFR then forget the fiddling with the bypass screws. Close both completely, sync and set idle speed with both throttle stops (left and right) and set the right mixture at the break points in the BIN. This eliminates the random flow of air thru the bypass screws at idle (and to a lesser degree at higher rpm). If perfection and transportability of a BIN between different bikes is the target, then the CO trim should be at 0.

     

    Cheers

    Meinolf

    • Like 2
  12. Hi Luhbo,

     

    the plain german statement is here: http://www.guzzi-forum.de/Forum/index.php?topic=30093.0

     

    For those not fluent in German. I was interested in the effect of the snorkels on the volumetrics of the engine and the impact the snorkels might have on the intake air temperature, so I measured AFR and air temp with and without them. The finding was that the engine run leaner to the tune of 1-6%. As the injection values were constant, the leanness resulted from more air moving through the engine at the breakpoints where I measured. The air temp didn't show any significant changes.

     

    When analyzing the logged data I also found that the fluctuations of the Lambda values went down from an average of +/- 0.25 to +/-0.08 (That is a factor of 3, and not of 4, as wrongly stated in my previous message. I'm not good at arithmetics). Which, to voice an opinion, indicates a much more laminar airflow with the snorkels than without.

     

    The summary is that well shaped air inlets, even if the diameter of the inlets is smaller (than the inlet in the airbox), are more efficient than sharp corners. Which is not a new revelation, but a long established fact.

     

    So, if one wants to do sound tuning, remove the snorkels. If one wants a more efficient system, keep or add them.

     

    Cheers

    Meinolf

    • Like 3
  13. Hi,

     

     

    ...but if you expect the best performance, the factory airbox is well designed.

    ...the consensus has been: ditch the rubber turn-down snorkels.

     

    I agree with the first point, but my measurements indicate differently on the 2nd one.

     

    When measuring air throughput with and without snorkels I found that it increases 1-6%. And air Lambda fluctuations decreased by a factor of 4 3.

     

    My impression was that the engine ran significantly smoother.

     

    Cheers

    Meinolf

    • Like 1
  14. Hi Ken,

     

    ... and the TI map is very rich...

     

    I find that the original TI BIN is not overly rich. In fact it is, assuming that a performance map should target Lambda 0.86 or less in the main areas, quite meager. 

     

    The picture linked shows the comparison between my (I have the TI exhaust) and TI BIN. 

     

    The cells with negative values are lower than the ones in my map, which has a Lambda of 0.88 across the entire map. And those areas where the TI is richer than mine are mostly the areas you can't reach. Like 1300rpm/61° TPS or 7800rpm/3.3°TPS.

     

    I found that comparing BINs, and more specifically the two fuel tables, at face value is useless. Nothing to be learned, a lot to be misunderstood or misinterpreted. To many factors contribute to the actual Lambda/AFR and the base and offset map are just the starting point. Along the way the values are influenced by the CO trim, the setting of the bypass screws, the acceleration map, the temperature trim tables and the ignition and ignition trim tables. And last but not least a well contacting and working engine temperature sensor. Don't ask me how I know  :P:

     

    https://db.tt/aQjNNxeq

     

    Cheers

    Meinolf

  15. Hi,

     

    some comments in addition to Camn's explanation.

     

    "titanium ecu software .... it is nothing else than the standard ecu and mapping which makes the motor run more rich"

    Not quite. There are more differences in the BIN than just fuel and ignition maps. But I couldn't find any differences which I believe are relevant to performance. But this might well be due to yet to be documented functions in the BIN. I will eventually copy the numerous changes of my current BIN on top of a Titanium BIN and see if there's a noticeable difference.

     

    "The ecu type “15M” and tps type “PF3C” are always as a pair there, and come from the GuzziDiag PC software."

    The string "15M" is in the BIN (beginning $AF00), PF03C is not. However, as GuzziReader doesn't copy the entire BIN to a file, PF03C might be contained in the code which we don't see. GuzziDiags adds, as Camn explains, the latter to clearly identify the TPS type which is assumed to be used on the motorcycle.

     

    This shouldn't be of interest under normal circumstances. The exception is if a TPS with a different resistance curve is used instead of the PF03C. The BIN contains two 16x16 tables (and a 3rd one for the Quota 1100) serving as lookup tables in which voltage values (from the TPS) and the associated TPS angles are stored. This is where you would have to change values if a different TPS is used.

     

    "C"X" => I have also been wondering this marking"

    Currently my best guess is that the characters after 15M either indicate hardware versions or are specific to the different customers. I have seen the 15M used by Ducati labeled with 15M.A2 and the MG ones with 15M.C5 or C7. And only recently did I hear that the 15M is also used in asian scooters, the designation used there being P. Go and figure.

     

    Cheers

    Meinolf

  16. Hi Jim,

     

    When looking at the ECU Information in GuzziDiag, both ECU's list:

    IAW 15M PF3C

    61600.537.01

     

    The set of numbers just below those identifiers are different though

    "good" ECU = 3D02VS9F

    "bad" ECU = DLXV11-S

     

    what you are seeing is data which is part of the BIN loaded to the ECU and can be changed with TunerPro or the like. 3D02VS9f is the code for the first V11-BIN from MG. I haven't seen the DLXV11-S in connection with a 15M or 15RC, but don't claim to know all codes.

     

    Don't you have any labels on the ECUs which give more information? If not, check the # of lines of the connector. The 15RC has one additional line for the lambda sensor. As the models which came with the 15RC are using the same temperature sensors, this alone would not explain the issue you experienced and solved.

     

    Cheers

    Meinolf

  17. Hi,

     

    based on ~50h data-logging at ambient temperatures ranging from 5-35°C and heights from 100-1200m and 2-3 weeks spent analyzing the accumulated data I now have a map which I find quite satisfactory. Power, subjectively, is better than the original map, even more important are smoothness and drivability.

     

    Would anyone like to try the map and share his experience? I only know my V11, so my impression is quite subjectiv.

     

    Starting point is a V11, 15M, 2001, 68.000km, Titan mufflers, standard collector, KN airfilter, no snorkels, no further engine or other modification. The ECU trim on my V11 is set to 0, so it should be adjusted accordingly.

     

    The target was this map with synchronous values at all operating conditions on both cylinders at all map cells reachable during normal street driving conditions. I experienced 5.0-6.5l/100km, depending on the driving mode - touring vs spirited curve chasing. The only remaining issue is some lean sputtering between 2.900-2.600rpm when decelerating with completely closed throttle.

     


     

    These are the cells I could reach during normal street operation (ignore the values, they are mean values from +14h logging)

     


     

    The changes to the map are:

    - base maps of both cylinders changed. Mean deviation at those points I could reach is less than +/- 0.01 Lambda

    - Reduced cold start duration to 2000 revolutions and made a proportional change to the cold start map values

    - Corrected trim tables for ambient temperature (I could not measure any AFR changes due to changed temperatures in the range of 5-35°C)

    - Corrected trim tables for ambient pressure (I could not measure any AFR changes due to changed pressure changes in the range of 100-1200m)

    - Changed ignition table

    - Changed acceleration map

     

    Cheers

    Meinolf

     

    PS Following a completely different topic I found today that the engine temperature sensor on my V11 did not fully contact the engine. The consequence was that the reported engine temperature was ~25°C below the actual value. And this resulted in messing up several areas of the map. So, until I have corrected these areas the map won't work well on any engine where the sensor is reporting the correct temperature.

     

    However, considering how the sensor is connected to the engine and that the design does not ensure a reliable heat transmission, the chances are that many V11 will have the same effect and consequently the map should work well.

     

    If GuzziDiag shows, after a normal run or about 10min idling, less than 85-90°C, the chances are that the sensor is not properly contacting the engine. An easy fix is to apply a drop of heat paste to the tip of the sensor.

  18. Hi Czakky,

     

    Sorry, I have no simple recipe. The prequisites are dual lambda sensors, a data logger, a target and the willingness to spend a lot of time in measuring and data analysis.

     

    On my bike I have invested several work weeks during the last year. And I'm not satisfied and finished yet. I'm at a stage where I gather several hours of data and then spend hours on analyzing just a couple of seconds.

     

    It has become a goal in itself.

     

    Cheers

    Meinolf

  19. Hi,

     

    I mounted my air temperature sensor at the front of tank. I figure it should be away from the engine heat. I removed the thermistor from the plastic fitting and extended the wires.

     

    two comments (based on a 15M, not all may apply for a different ECU).

     

    First, the air temperature sensor is providing intake air temperature to the ECU to allow for variations in the air mass, which the air temperature trim table is supposed to compensate. The target being twofold, an AFR which is not changed due to air mass variations and changes to the ignition timing in case the air temperature exceeds a given temperature (AirTempSparkTrim table).

     

    Second. I have logged the air temperature on a V11 (no snorkels) with the sensor in the airbox and almost no influence from the engine temperatur or engine load is discernible. Ambient air temperature seems to be the only significant impact. In below picture the blue line is engine temperatur, the red one rpm and the orange one air temperature. The air temperature stays at ambient temperature plus a couple °C, even when idling after high loads.

     

    Cheers

    Meinolf

     

    https://db.tt/8T61QNDL

  20. Hi Hubert,

     

    it depends. Not having done and tested an ignition map for a dual-plugged V11 with a 15M (my following thoughts are partly based on the current understanding of the 15M, other ECUs. Especially those with closed-loop, are a different topic) I would tend to follow past experiences.

     

    Dual plugging of twins brought the biggest benefits to those designs (for example the old LeMans1-5 or BMW R90S) which used a raised piston dome to achieve high combustion, which resulted in an ineffective design; larger surfaces leading to higher heat dissipation and a convoluted combustion chamber. At that time a rather rich mixture was (legally) possible, so the negative influences could be countermanded by just richening the mixture. A rich fuel-air mixture ignites better and burns faster.

     

    The combustion chamber of the V11, using a semi-spherical design, and the quite flat piston are actually quite good for a 2 valve head. However, at the time of design of the V11 emission values became a design-critical factor. Which lead to leaner mixtures, which lead to much higher pre-ignition values than the old designs with raised piston domes and rich mixture needed.

     

    Given that adjusting the mixture by changing the respective maps, based on AFR readings readily available using relatively cheap equipment from Zeitronix or Innovate, is possible now I would start of with a ignition curve which is similar to the old LeMans. Which at WOT is actually close to the 8° which sp838 (I do wonder why so many hesitate to use a name instead of a nick) suggested earlier on. But at intermediate rpm/settings, where one would strive for a mixture less rich than the one desirable at WOT, the pre-ignition could be closer to the original map.

     

    It gets a bit more complicated at low rpms. At and close to idle the ECU uses a formula to change pre-ignition, based on the ignition maps. The differences I have noted are close to or bigger than the pre-ignition of the old Le Mans, so I would start of with the original ECU values.

     

    Does that make sense? I haven't yet come across an ignition map from one of the tuners such as DAES or Dynotec modified for dual plugs. I'd be happy to get one.

    Cheers

    Meinolf

  21. Hi,

     

    a uniform decrease of 8° at all loadpoints probably won't work. 

     

    Instead of going for new pistons you can achieve a compression of ~11 by taking 1mm of the the cylinder heads and shortening the the cylinders by 0,5mm. This would also give you a decent squish area, which the standard setup doesn't have.

     

    Cheers

    Meinolf

  22. Hi,

     

    you can change the ignition map of the ECU with programs such as Tunerpro. Download the map using 15M-reader, change the values and upload the new map with 15M-writer.

     

    While I don't have any advice how much and in which areas (rpm/TPS) the ignition should be changed, it definitely should be retarded.

     

    Cheers

    Meinolf

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