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On Aftermarket engine managment, Alpha N, etc.

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  • On Aftermarket engine managment, Alpha N, etc.

    Hello, I have this introductory
    article written by a friend of mine
    Jake Larsen. Jake is probably know by
    many of you from the SIG. This is where
    the article was orignally posted. The article
    may not have all things explained
    in 100% detail, it was written some time ago.
    But, it is still a very good article and a
    good read, typical of Jakes articles. He
    explains decisions and tradeoffs, especially
    important for those who do not have unlimited
    resources at their disposal.



    intro/writeup by Jake Larsen


    Well here goes. I need to mention right off the bat I don't have any practical
    experience with any after market engine management system (EMS).
    But what I have done is a large amount of research and physically looked over
    several set-ups. So take what I say for face value only, I'm no expert. 8-(
    I'll touch on some of the available systems out there but I'd mostly like
    to talk generally about engine management. I don't have the experiance to
    really rate different systems.
    I think the first thing to do when looking for an EMS is to decide what
    your overall goal is. There are several questions to ask that could help
    determine the level you wish to take it to. Here are some of the questions I
    ask myself with a little of my own opinion splashed in for good measure:

    -Are you simply looking for a way to get rid of your AFM?

    Understandable. The classic example is the Split Second system. Ya know
    they never mention setting it up on a dyno. Yikes! You make adjustments for
    drivability and then your set. Your even free to use the chip of your choice.
    Not a bad deal. Well.... sort of.
    So supposedly you can take any aftermarket chip, which was mapped to a
    certain engine configuration, install it into an ECU getting user adjusted
    signals for air flow from a signal conditioner calibrated using a cheap A/F
    ratio meter, and it gives you a correct map for an engine now less restricted
    and unlike the engine it was originally intended for?
    The only way I'd believe this is if you actually set it up on a dyno and
    burned a chip for this set up. That would do the trick. And use a better A/F
    ratio meter while your at it. The one it comes with is not very accurate but
    its still able to get you close. This is one problem. Another is calibration
    accuracy. The signal conditioner (ARC2) adds another stop in the path of
    signal to the ECU. By itself, the stock EMS already has inaccuracies but it
    doesn't really cause any problems.
    The signal conditioner, and any other component for that matter, also has
    inaccuracies. The more stops in the process the more any inaccuracy get
    compounded. This is one of the inherent problems with introducing a signal
    conditioner to compensate for the differing output of the MAF sensor.
    Quite simply, installing a signal conditioner such as what's offered in the
    Split Second kit is a band aid fix to a conversion that isn't even necessary.
    You don't need an MAF sensor or an AFM to manage an engine. In fact, both
    these methods of air measurement are prone to reverse pressure waves in the
    intake tract. This causes problems.
    Big cams on an AFM and even an MAF sensor can cause scattered signals as
    intake reverse pulses bounce the flap in the AFM or disturb the cooling
    effects on the hot wire in the MAF sensor. The results can be a very lumpy
    MAF conversions have been made popular because they make immediate sense.
    An explanation of the restriction caused by an AFM and how a MAF sensor flows
    much better is an easy one to grasp.
    What you don't see is how inaccurate the system really is. Does it cause
    any problems that most would notice? Of course not. It's just that some
    people also don't see that this really is just a half assed way to stick a
    MAF onto an AFM compensated system.
    The Split Second system has been made popular with good marketing. It makes
    sense and people don't see the need to do any more research. It appears to
    answer all their questions so why rack your brain to ask anymore. If you
    don't have a laptop or want a system which seems to allow you to set it up on
    your own not using a dyno, then be my guest.
    There are better ways to eliminate the AFM. And the truth is, the
    alternatives are more accurate and cost about the same. Some even less. Using
    throttle position, rpm, crank position, with corrections for air temp,
    coolant temp, and MAP, you end up with an extremely accurate system capable
    of better performance than any MAF conversion.
    From there you can add cam position for proper sequential injection and
    wideband lambda sensor for accurate calibration. In the end, I'm left
    wondering why I would "want" to do a MAF conversion.
    Here's a good thing to know. You can purchase a fully 3D mappable system
    for just a bit more than what a MAF conversion kit costs. And if you consider
    taking a MAF conversion to a dyno and burning a custom chip you'd definitely
    be in the territory of a "real" 3D mappable EMS anyway.
    You may regret buying into the Split Second system if you find later you
    could've had a "true" EMS for about the same and have the ability to program
    your own engine management. There are several manufacturers offering systems
    that come very close to the cost of the MAF conversion kit.
    Now before all our Split Second users kill me, let me just say that this
    kit obviously works. Many people have been using it for a long time. There
    are real gains and it's easy to see and feel the results. So there ya go.
    Should someone not do it? Well, it works as advertised and people who do use
    it are happy. Can't argue that. 8-)

    -System cost a large part of the equation?

    It always is. But what limitations are you willing live with? You should at
    least know what they are and decide for yourself where to draw the line.
    Educating yourself on this subject will go a long way in insuring your
    getting what you want. It's a very misunderstood subject and there are people
    out there who pray on that.
    Sometimes people understand only that the AFM is something they don't want.
    Choosing a system only for this feature and not knowing what else to look for
    or what to watch out for can hurt you in the worst place. Your pocket book.
    Relying on someone else to decide system limitations for you could set you
    up for disappointment. And entering any modification like this uneducated is
    doing just that. If you were planing on future upgrades but find later it's
    impossible, you'd be stuck with buying another system or just not continuing
    the evolution or your engine's management system. Additionally, with cost as
    your only goal you can end up with a poor system which doesn't suit your
    needs. Just something to consider.

    The kinds of things which effect the price of various 3D mappable systems

    -Included options; sequential injection, traction control, data logging,
    wideband lambda measurement, telemetry link up ect. (telemetry is were all
    your engine conditions can be sent to a PC or laptop via satellite
    communications so your pit crew can "watch" your engine as you go out and rip
    it up!).

    -Ease of use; presentation, program design and layout, graphics ect.

    -Upgradeable/adaptable; adding more inputs or outputs, adding memory, field
    upgrades (ability for user to do it him/herself), ect.

    -Resolution; # of RPM/load sites. Some systems will give you 40 RPM sites
    each with 21 throttle position (load) sites (40x21=840 separate sites).
    Others offer as few as 22x17 (374 sites) or even less.

    **Think of this as just a graph or a table. Up one side you've got RPM.
    Across the bottom you have throttle position. With a 40x21 map you have 40
    rows of RPM sites and 21 columns of throttle position sites. Where they
    intersect a value is given and adjusted. For the ignition map you have
    degrees of advance. The fuel map will give injector pulse width. Can someone
    feel the difference between a low and high resolution system? I don't know. I
    can only assume.

    -Processor speed; just like your computer. The higher the resolution and more
    options configured into the system, the faster it needs to be.

    -Memory size; this comes into play more so when data logging.

    -Ignition calibration accuracy; measured in degree of crank rotation i.e.
    40deg of advance +/- 0.25deg.

    -Fuel calibration accuracy; measured in fraction of a second (x.xxxxx sec).

    **An injector pulse width is the percentage of time an injector opens within
    one revolution of the crank. Of course the available time for the injector to
    actuate decreases as engine speed increases. 100% open at 3000 RPM is twice
    the time as 100% open at 6000 RPM. Same percentage but half the actual time.
    Can you imagine how much time is left for the injector to actuate when your
    spinning at 8000RPM? This is were the accuracy comes into play and why it's
    measured to the millionth of a second. Remember the signal conditioner added
    to a stock EMS? Accuracy plays a big role with injector pulse width values.
    It's not going to be there on a frankinstien system.

    -Available compensation maps; air & coolant temp, MAP, battery voltage (this
    effects injector pulse width) ect. Surprisingly, some systems do not offer
    even the basics.

    -System self diagnostics; surely quite helpful when troubleshooting. If we
    all had this we could eliminate the billions of posts asking for help with
    their hesitation, rich running, and misfiring S14's.

    -There is soo much more.

  • #2
    PART II -- by Jake Larsen

    Ease of set-up an issue or does it not matter if your going to have someone
    else do the conversion anyway?

    If your going to have someone else install it and map it, what difference
    does it make? If the shop you've decided to have carry out the work sells &
    installs a particular brand you should use it as long as it works into your
    overall goals. Mail ordering a completely foreign kit and handing it to your
    tuner could led to unforeseen problems you just don't need and possibly cost
    more in the end.
    On the same token if your going to be installing and setting it up
    yourself, and this is your first time, it's user friendliness should play a
    big part in your decision. Wouldn't it be worth the extra dough to be able to
    easily make heads and tails of the entire procedure from the get go? It is to
    The more attention you can apply to the job at hand and not simply figuring
    out what your doing, the better tuning job your going to get. If it's a
    constant bitch to make adjustments your going to want to give up. Pretty soon
    "good enough" is what your left with. That and a bad taste in your mouth of
    after market engine management.
    My personal reason for wanting an aftermarket EMS is for learning. This is
    just a hobby for me and the whole concept of it sounds like fun. For this
    reason, system effectiveness is not my only concern. I want one that will
    allow me to enjoy it. True, it may require a little fluff with cool graphics
    and displays but I'm doing this for fun and not just for function.
    Performance is one thing. An interesting tool to play with is another.

    -Do you want to make adjustments using your PC or laptop?

    Some systems do not allow this. They are intended to be put on a dyno and
    have a chip burned. Piggy back systems are like this. Well let me clarify,
    most signal conditioning type modifications are like this. You don't hook up
    a laptop and remap it.
    Back to the Split Second system, this is a good example of what I'm talking
    about. This system does not have provisions for hooking up a laptop to make
    adjustments. It's simply just a signal conditioner.
    Other systems include a mini mapping control panel with a LCD screen.
    Usually these are not programable on a laptop. These are easy to use but are
    not quite as good where overall quality is concerned. These are touted as
    being very easy to use because you don't have to use a laptop or PC to set
    them up.
    Probably a great beginner system. They also reduce the overall resolution
    of the maps and simplify everything to make them manageable on a small
    control panel. You can accurately read "simplify" as less options and/or less
    quality. But, I'm sure some would argue that.
    Systems at the top of the food chain don't use these hand held controllers.
    They normally "do" use laptops or even PC's for programing. You get better
    displays, more logical graphs using a normal computer over the hand held
    controller versions. Programing via laptop or PC is not mandatory for a good
    system. Just something to keep in mind.
    If your going to be fiddling with it constantly and monitoring your engines
    current state of tune you should again look for something that is very easy
    to use and understand. If your going to just install it and drive, who cares
    if it's easy to use? Your only going to do it once.

    -Do you already have experience with setting up an EMS?

    If you are well versed in the art of engine tuning using a PC/laptop mapped
    EMS, obviously you can bypass all the fluff. You don't need all those cool
    digital dash programs and 3D mapping graphics to map your engine. The
    importance of presentation may not be as much of an issue as long as it's
    still logical. I know I'm not telling the vets anything new but I just wanted
    to point out that if your a beginner as I, find the easiest system you can
    with good displays.

    -Do you have access to a dyno or do you know of a dyno shop that can set-up
    your particular system?

    As we all know, dyno time is part of the process. If your living in Alaska
    and you'll need to drive a billion miles to a dyno, a project like this may
    not be possible. Mail order chips or premapped systems may be your only
    practical choice.
    Some shops may stipulate which systems they'll set-up and then refuse
    everything else. Reason being, they do not want to be held accountable for a
    set-up using a poor EMS or one they're not familiar with. If there is fear it
    can fail and take an engine along with it, they may not want to carry out the
    Also, don't worry if they've never worked on an S14. If they are
    experienced in installing and mapping an engine, they can do ours. The engine
    itself has very little to do with the ability to install a system and map it.
    Engine assembly sure. But mapping an engine is no more than looking at a
    computer screen and making adjustments. Yes I know. I'm way over simplifying.
    It's just important to know you don't have to tie yourself to only S14
    experienced tuners.

    Here are some of my own goals. Money is money, and I don't have a lot of
    it. But, in certain cases I feel I would be doing more harm than good trying
    to save a buck. I want this to be a pleasurable experience, not a frustrating
    one. I'm not saying you've got to spend a wad of cash to make it a good
    experience. I just don't want to let that get in the way of having one.
    Someone once told me, "Your always better off spending too much than
    spending too little. The pain of spending too much diminishes over time and
    your left with something better. Spending too little lasts forever as you
    have to live with the limitations associated with it." Plus if your unhappy,
    you may end up going back and spending the big bucks anyway. Then you'd be
    out even that much more.
    Keeping this in mind, I'll look for the system that meets my needs. Nothing
    more, nothing less. Ease of use, accuracy, logical layout, adaptability,
    resolution ect ect. Making things interesting is important as well.
    Of all the systems I've looked at, MoTeC has always been at the top of my
    list. The M4 Pro goes for about $1800. This gives me everything I want as far
    as the ECU is concerned. Mind you this is just for the ECU. You'll need to
    add a few sensors and build up a wiring loom. Usually you can use a large
    portion of your existing loom so we're not talking about a major headache
    Add a few sensors common with any other after market EMS and your done.
    Install it and map it on a dyno just as any other system would. Only the
    overall quality differs from other cheaper systems.
    Mapping can take a little longer with an EMS like this just because there
    are more "sites" to program. And if your using additional sensors as this
    system can allow such as EGT sensors to trigger certain outputs or what ever
    you want, set-up time will also reflect. But by no means is it because it's
    "hard" to set-up. It simply has more options.
    The next level of engine management runs around $1500 with basic systems
    starting out around $800. Yes, cheaper than the Split Second kit. Sorry, I
    don't mean to pick on Split Second. Their just an easy target. 8-)
    Some of these systems say they offer wiring looms but keep in mind they are
    generic and exact wire lengths are not accurate. I have yet to see one that
    offers one particularly for the S14. They seem to always custom make them
    anyway. Some include all the required sensors as well. Not a bad deal. But
    there are differences in the quality of sensors too, so beware.
    If your still with me and still interested you should go to and read this
    next site. It will cover all the basics of engine management even further
    than I have here. Definitely good reading. It's all explained in simple terms
    and actually flows quite well. If ya can't get to it due to some AOL thing
    let me know and I'll cut and paste it into an email and send it to ya.

    Discover the latest breaking news in the U.S. and around the world — politics, weather, entertainment, lifestyle, finance, sports and much more.

    Here is a list of web sites to aftermarket engine management manufactures.
    Have a look through them and get a feel for what is typically offered. You
    can get a real good idea of what to expect for your money by studing a good
    chunk of the market.

    Simple Digital System EM-5 is the most affordable, easiest to install fuel injection system on the market today. SDS does not require a laptop to program!

    Engine control system for the serious performance & racing pros. Electromotive is the leader in performance ignition systems & engine management systems. XDi & TEC Worldfamous.

    Discover the latest breaking news in the U.S. and around the world — politics, weather, entertainment, lifestyle, finance, sports and much more.

    FAST is the leading developer of electronic fuel injection systems, EFI components, intake manifolds, tuning tools for high performance and street applications


    • #3
      My eyes hurt!

      Nice LONG read!

      Disclaimer: Remember, I know absolutely nothing, but it doesn't prevent me from having an opinion or suggestion. :


      • #4

        Disclaimer: Remember, I know absolutely nothing, but it doesn't prevent me from having an opinion or suggestion. :


        • #5
          Perhaps this should get a sticky or designated place on the site... I have never seen this post before and it's certainly a good one!!

          EDIT: perhaps a folder in the archives could be made in pertainance of engine management exclusively... other threads could be compiled... seems to be a popular topic.
          Last edited by Beau; 05-31-2004, 03:53 PM.


          • #6
            Yes! I've been compiling....

            Disclaimer: Remember, I know absolutely nothing, but it doesn't prevent me from having an opinion or suggestion. :


            • #7
              i would like to see what he has to say about the generation 2 split second kit since it uses the lap top and not the knobs to which he is comparing the SS to everything???
              Old School


              • #8
                Where do you find the time Jake or do you just like typing I feel less typing and more working on the M3 is required :p

                Still good stuff and informative.
                "It's not the mountain we conquer but ourselves"


                • #9
                  Don't forget that Jake is potentially (probably) being shipped off to Iraq.......... :(

                  Disclaimer: Remember, I know absolutely nothing, but it doesn't prevent me from having an opinion or suggestion. :


                  • #10
                    Originally posted by Magnus
                    Don't forget that Jake is potentially (probably) being shipped off to Iraq.......... :(
                    Yeah I know, I hope it all goes Ok for him. He will be missed around here.
                    "It's not the mountain we conquer but ourselves"


                    • #11
                      Good thing Brandon keeps popping his head in. We ain't forgetting you either Bro-man.

                      Disclaimer: Remember, I know absolutely nothing, but it doesn't prevent me from having an opinion or suggestion. :


                      • #12
                        I'm sure that someone over here got a second generation Split Second MAF kit and Bexley Motorsport fitted it. They said it was a real PITA as you couldn't load maps up or change the figures on the go. I'm sure it was something along those lines. You had to keep stopping and turning that car off to change the data. Which made the mapping a long drawn out process, expensive too as dyno time is not normally cheap.

                        I can find out for sure if you want to know?
                        "It's not the mountain we conquer but ourselves"


                        • #13
                          Thats correct. To upload changes you have to turn off the engine, then back to pos 2. Then upload. It is slow as hell too. I hated having to pull over, upload changes, then drive again only to find out the changes were wrong.



                          • #14
                            Bosch POT part number


                            I am just about to get either an MBE or Emerald system fitted and am currently getting the sensors and loom myself to keep the cost down. Can you or anyone advise the part number of a Bosch POT that will retrofit directly. I have sourced the other sensors and the toothed wheel but am unsure about the Bosch POT.
                            A likely candidate is either 0280122001 or 0280122201 but I dont know.


                            • #15
                              any pot that will fit on the spindle and interfaces
                              well with your harness.

                              the 6 pin version used on the maxx AN is
                              0280 120 402. perhap you should also take a look
                              in the motec catalgue the have quite a few different
                              pots listed.