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On Aftermarket engine managment, Alpha N, etc.

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  • #16

    Would you have the pin-outs for this the 6 pin version used on the maxx AN is 0280 120 402.

    Also what is it from as I am having trouble finding a 6-pin plug for it


    • #17
      So, is there anyone out there who is using ANY of these systems on a street driven US spec E30 M3 ?
      Mike Allen
      San Antonio, TX
      Founding Member, Old Phart's Racing Team
      (Indoor Beer Consumption Division)


      • #18
        Well, if you take the time to browse around on the site youll find out there are
        many people successfully running a Maxx Alpha N setup on their US spec M3.



        • #19
          So, while installing this air box, you ditch completly the stock DME and replace it with a Alpha-N controller that comes with the airbox kit? Need buy it seaprate? Or you just can select any standalone system outhere?

          I'm on MS II in my e30 turbo....but for the M3, how does it works with the airbox kit?

          Or the controller that might come with the air box kit, only replace the fuel trim and the stock DMW it's retained to control spark?
          Euro M3'87 NogaroSilver / Euro E34 M5 '93 / Porsche 993 TT 97' Euro / Porsche 993 Carrera 95' Euro / Skyline R33 GT-R


          • #20
            Im trying to get a feel for other engine management systems. i know Maxx is the popular one, but what about some of the japanese tuners? For instance Greddy? Apex? I saw a thread on using the Apex SAFC and was wondering if anyone had used that. I would think it would be a good piece since it has a screen etc, it would be easier to tune. honestly i thought that particular piece was just for adjusting basic air/fuel (like a RRFPR or something) but could it replace the AFM?

            Im basically curious to know if there is anything that may be easier to use/tune and be cheaper than Maxx. I dont doubt the Maxx system is widely used because its a good piece, but id like to know more.

            Apex Neo:
            Apex Power FC
            Apex SAFCII
            Apex SAFC Select
            Greddy E Manage
            HKS F ConIS

            Real M3s have 4 Cylinders


            • #21
              I've used the Apexi super afc and it was an improvement over stock but does not run a car without the afm. I removed mine after getting the Maxx alpha n.


              • #22
                after doing a bunch of digging through really really old links and a bunch of forums, i finally found Gustave's old write-up on Alpha-N.

                it's a good read as well:

                Alpha-N Explanation
                .Courtesy of Gustave Stroes

                Components of a typical Alpha-N kit.................................................. ....................

                I know many folks on this board understand quite well what Alpha-N is, but this is for those who don't understand it. I remember how that felt, so I will offer my version of an explanation.
                An engine management computer, regardless of how sophisticated or crude, really only controls two parameters. The ignition timing and the fuel delivery. The computer (DME or some aftermarket brand) uses an array of input sensors to try and determine what state the engine is in at any point in time. Is it loafing along on the freeway at low rpm, or at max throttle climbing a hill at high rpm? Is it hot outside so that the air is thin? Or is it butt cold and the air is real dense?
                The list goes on, but the goal of the computer at all times is to sample its input sensors and then determine the appropriate output signals for ignition timing and fuel delivery (usually this determines how long the fuel injectors fire, which is called the pulse width, but it can also entail "when" to fire the injectors if the injection is sequential).
                The two most important things that the computer wants to know in order to determine spark and fuel are: 1) engine load, and 2) engine rpm.
                Engine rpm is easily determined from a crank sensor. But engine load is a little more tricky. The best parameter to use in determining engine load is the MASS of air entering the engine at any time. If you can measure the mass of air directly then you are well off. Current BMW's do just this with what is called a MAF sensor, or mass air flow sensor. This is usually some type of heated wire or film, which is cooled by the air flowing over it. In order to keep the wire at the same temperature additional electrical current must be provided, and the measure of this extra current gives a fairly direct indication of the mass air flow.
                Our E30 M3's used a similar system, although it measures the VOLUME of air flowing into the engine. The sensor is called an AFM, which stands for air flow meter. The volumetric flow is determined by how far a flapper (or barn door) is pushed aside by the incoming air. The flapper is connected to a potentiometer (variable resistor, POT, wiper, there are many names). But for the computer to know how much fuel to mix with the air it needs to know how many molecules of air are coming in, and that can only be determined by knowing the MASS of the air, not just the volume. So, we need to combine the AFM air volume signal with an air TEMPERATURE measurement Then the air mass can be determined. So we are ok.
                Note that in both cases the computer has some hard data on how much air is entering the engine, so if you improve engine breathing (header cams etc...), the basic code will still sort of work as the computer is aware of the additional air. It's not perfect, but it works ok most of the time for changes that are not too drastically different than the baseline.
                Alpha-N is different. Here there is no direct measurement of either the mass of air, nor the volume of air entering the engine. That way any possible obstruction from either a MAF sensor or AFM sensor in the intake path is removed. The air can flow right into the engine unobstructed. So how does the computer know what to do? It still has rpm info from the crank, but it can't measure the mass of air coming into the engine for fuel mixture determination?
                The answer, in a crude sense, is that you "train" the computer what to do in a given situation (on the dyno). For every possible combination of throttle position and rpm, the tuner determines the appropriate ignition timing and fuel delivery to yield max power but not incur detonation. The computer just remembers all this (in the form of maps which are stored on a chip), and when it sees a certain combination of rpm and throttle position in the field, it just says "what did they tell me to do in this situation?" and does that.
                So now throttle position and RPM are the two dominant input parameters to the engine computer. This is where the Alpha-N name derives from. Alpha for the angle of the throttle plates and N for RPM.
                Now if you have an Alpha-N system, and add a hotter set of cams that allow more air into the engine, but you do not reprogram the Alpha-N computer, then the computer has no knowledge of the extra air now entering the engine and it just gives the fuel and spark that it was told was appropriate for the milder set of cams. One can see how this could be a problem. Your mixture especially, but also your ignition timing will be way off. If your mixture goes lean you can potentially damage the engine. That is why folks say that an Alpha-N system needs to be retuned everytime you make a change to the engine. The computer is "flying blind" to some extent, although it does at least have an air temp sensor and a barro sensor to try to compensate for density changes in the air due to temperature and elevation.
                I have oversimplified some subjects to make it easier to understand, and as usual there is probably more that I did not say than that I did say about Alpha-N, but hopefully that gets some folks a little closer to understanding it.

                Bay Area ///Motorsport
                article found here:

                ...what's the best deal on a plug-n-play MS2 setup that anyone's found? I'm looking for something effective to do with this 91m42 that has a trashed harness, and MS2/3 would leave me plenty of room for the future.

                how different are the EFI systems between the s14 and the m42? (note: i don't care about petty part numbers, just system structure and operational theory)

                good OP btw


                • #23
                  maybe worth talking to MAXX directly. New MAXX A/N is wideband band CONTROLLED!

                  Goodbye M3, you served me well.


                  • #24
                    The major drawback with the MAXX alpha-n setup is the ignition map is not user adjustable.
                    2003 Mitsu EVO VIII - 2.0L / 600+whp
                    1988 BMW M3 turbo - Work in progress. . .
                    1986 SVO Mustang - Work in progress. . .


                    • #25
                      I agree Ted. The ign map most end up using is in the stock eprom, and this map is calibrated using mass air flow from the air meter which has a different airflow vs voltage curve to a TPS. So, invariably the ign map is incorrect and potentially dangerous.

                      Ther are cost effective EMS solutions out there.

                      Just my 2p

                      Sport Evo No.47

                      My Sport Evo Restoration