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Can someone provide me a good ms AFR map?

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  • Can someone provide me a good ms AFR map?

    Hi!

    As above, does someone have a good AFR target map for megasquirt?

    Kind regards
    Daniel

  • #2
    Doesn't anyone of you Megasquirt guys have a descent AFR target map?

    Would really appreciate any help!

    Kind regards
    Daniel

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    • #3
      Hello Daniel,

      I don't understand what you're looking for. Are you running speed density or Alpha-N?

      I think most of the guys here that are running MS are running A-N.

      -Dietrich

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      • #4
        Hi!

        Sorry about that! I am running ms in speed density mode.

        I just need a something to start with. What differ the speed density vs the alpha map? Kpa vs % throttle?

        Regards,
        Daniel

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        • #5
          So, what do you guys think of this?

          Am I way of?

          Regards,
          Daniel
          Attached Files

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          • #6
            Alpha-N is Throttle vs RPM.

            How are you getting your MAP signal? Just running a line from a tee fitting at the FPR will not work - you need to tie all TB's together into one signal (Check Anders' threads for his setup). Even then, his MAP sensor was mounted at the TB's, not internal to the ECU back in the car. We put my car on the dyno and ended up going pure Alpha-N for both fuel and ignition loads after seeing some crazy fluctuation of the MAP signal under load...

            Also, if you were going to run MAP, you would need to log what range you are seeing for your motor, and use that range to set the bins. IIRC I was seeing ~60kPA at ~1100 rpm idle.

            Brendan
            sigpic
            Track Car Build | COM Sports Car Club

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            • #7
              on my stock 320is I get 12.3 at WOT and as 'lean' as 15.3 on part throttle. Look for posts by france320isco he has supplied AFR's in the past.

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              • #8
                Hi!

                Thank's for the answers!

                Well, I connected the TB's to a "vacuumstation" and on to the MS and FPR. This should help preventing the fluctation by stopping the pulses from getting to high. So I've been told... To be honest i haven't recorded a log that confirms this, but I will.

                The reason why I wanted to change the map in the first place was mainly a VERY annoying problem. At 3800-4000 RPM there is a "misfire", sometimes very weak and sometimes stronger. Changed everything rotor, ign wires etc without any succes. So, I figured it must be the map. The second reason is, of course obvious, more power :peekaboo:

                But since there aren't many Speed density maps around I am thinking about changing to Alpha-n. This mean I have to change my entire MS Map... :-(
                Any help, Ign tables, Fuel tables etc. would be helpfull...

                A complete MSQ file would be perfect, of course.

                Read somewhere that there is a third alghorithm called "Hybrid Alpha-n". I quote, the Hybrid Alpha-N adds the MAP value into the fueling algorithm. Is this setup for boosted engines only or could you use it on N/A engines to? Thinking that, more "calculated fields" the better, or?

                Hybrid_Alpha-N
                With a boosted engine using Alpha_N, you MUST use the Hybrid_Alpha_N setting (See Advanced Settings) with Megasquirt, because the throttle position bares little relationship to the amount of air going into the engine. Alpha-N is for naturally aspirated engines ONLY, the Hybrid Alpha-N adds the MAP value into the fueling algorithm, (obviously the map sensor will need to be connected to the inlet manifold) so fueling is increased with boost pressure.
                Please Note: There is no extra table or any other settings other than selecting the option in Advanced Settings. It is simply used to add the MAP value to the equation.
                To use Hybrid Alpha_N ensure you have Alpha_N selected as above (HERE) then simply set your Constants - Control Algorithm as Alpha_N and set the ini file in MegaTune as Alpha_N, see HERE.
                Hybrid can then be used if it's set in Advanced settings, see HERE.
                Hybid Alpha-N =
                PW = REQ_FUEL * VE * TPS * MAP * E + accel + Injector_open_time
                Normal Alpha-N =
                PW = REQ_FUEL * VE * TPS * E + accel + Injector_open_time


                Kind regards
                Daniel

                Comment


                • #9
                  Daniel,

                  Make it easy on yourself - go pure alpha n for fuel and ignition. Don't multiply in MAP either - tried this on mine and it wasn't working because of some strange map resonance at middle rpm's. It is possible to MAP working, but it's much more involved. If you're determined to try it - have you read Anders' thread on his setup? Make sure you do before you go any further.

                  I can provide fuel and ignition maps for a pure alpha-n setup - but you will need to re-tune anyways as they are specific to my motor.

                  Brendan
                  sigpic
                  Track Car Build | COM Sports Car Club

                  Comment


                  • #10
                    Hi!

                    Yes, I read Anders thread and other ms SD/AN threads on the net and now understand that the best way to run an S14 N/A engine and other Multi tb engines are by using the Alpha-n algorithm. I've been struggeling over a year trying to make it work with Speed density, bad choice.

                    To further convince others and myself I created a log couple of days ago, the map fluctated like crazy.... I have to start listening to advice earlier, it saves a lot of time.

                    Also found Bry's? Msq files and started working with them. Loaded the map's into Tunerstudio and let the program do the rest. The car runs better, without hesitations and strange misfires as before. Alpha-n is the way to go...

                    Brendan, yes I would really appreciate if you send me your MS files.

                    Thank's for your help!

                    Kind regards
                    Daniel

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