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Alpha N Tuning???

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  • Alpha N Tuning???

    Does anyone here have experience with alpha n tuning (or know somebody who does)? That is, tuning a vehicle that has nothing but TPS, crank, and cam sensors.

    A little backstory.. I recently joined my school's FSAE team. We build a car from the ground up that uses a 600cc motorcycle engine running a 20mm restrictor and tune it all with an aftermarket ECU (in our case, an AEM EMS-4).

    I joined and the car that was built a year before I joined was running pretty poorly. The car is called the KS1. Every year, we host an invitational event in February and invite teams from across the southeast to compete with us. Around December, our entire engine/drivetrain team basically dissolved due to various personal reasons, and I (someone with no EFI tuning experience) took the helm to start getting it running properly for the invitational.

    At the time, our intake was 3d printed and leaked like crazy. I fixed that issue, threw the car on the dyno, immediately realized the TPS was dropping out randomly (thus making the car completely drop to idle fuel whenever it wanted to), and realized the intake was now leaking around the throttle body (it was a slide type) so I said screw it, designed an aluminum intake using an OEM throttle body (Honda Grom) which solves the TPS issue at the same time as the vacuum issues. I also decided to wire a WB o2 sensor (LC2) into the ECU so we'd have some sort of o2 feedback (previously, we were using the wideband that is attached to the dyno). Also, added a MAP sensor just because why not, we already had the loom opened up... and I figured it would make the car easier to tune.

    Let me just say... I'm in over my head, I have little to no idea what I'm doing, I understand the basic ideas but I'm definitely no tuner. I took a base map from the previous years car which has pretty much an identical setup minus a slightly different intake.

    The current issue I'm facing is the car will run fine steady state, but as soon as I transition to WOT it absolutely pegs the wideband lean (18.0) and the car has like no pull. It was brought to my attention that if you're running TOO rich, it can actually make the wideband read lean. I never even really considered this would be the case, because it never smelled super rich to me, but tonight I had to move it between our buildings and it almost knocked me out how rich it smelled. I am assuming since I fixed a bunch of intake leaks, that is basically making it run super rich. However I'm obviously confused about this since this tune runs just fine on our other car which again, has the same injectors, fuel pump, etc.

    Does this sound right? Could it just be tuned way too rich? I did pull the plugs and they were carbon fouled, not anything like a lean plug that I've ever seen, but I just assumed it was fouled because we spent a bunch of time tuning the car's idle, and a lot of that time it was running pretty rich. As soon as I moved on to actual dyno pulls and tuning, I swapped out the plugs for non-fouled and properly gapped plugs. I plan to pull THOSE plugs tomorrow morning as soon as I go in and see if they are carbon fouled.

    However! Let me get to the point. Like I said, I'm in over my head. I'm fairly confident in the fact that I've gone over the mechanicals of the car and found nothing that might be causing issues. (Fuel pressure is fine, injectors are fine, compression is fine, blah blah blah... all seems to be fine) What I am not confident in is my ability to get the tune to a decent place by February 25th.

    For that, I'm hoping I can find help. If you or anybody you know is a capable, intelligent tuner... please help us! We can probably find a way to reimburse you (though probably a fraction of what you might charge an actual customer) but you can get a warm fuzzy feeling knowing that the event we're trying to get the car ready for generates money for the Robert Glenn Allen Memorial Scholarship, which supports outstanding Mechanical Engineering students. In addition, if you're a business owner, we could bring you on board as a sponsor, which would get your name on our car or we could bring the car to various events you may attend.

    Regardless of whether or not anybody can provide assistance, you are all welcome to come out to the invitational--it is February 25th pretty much all day long. Delta TechOps will be there providing food out of their awesome airplane inspired grill, and I'm pretty sure there will be people there from Elan, Panoz, Deltawing, etc. Even if our team doesn't have a working car, there will be other cars there and there will be racing--rain or shine!

    Thanks for reading.



    ^This is the SP-14, which has been our most reliable car, and placed 17th over all and 3rd in acceleration in the whole country, somewhere around 3 seconds 0-60



    ^This is the KS-1, the car that desperately needs some EFI magic.



    ^Here is a rendering of the car we are currently manufacturing, the KS-2



    ^Delta Tech Ops' awesome grill

    https://www.facebook.com/events/205685946548887/
    Last edited by twolf; 02-13-2017, 11:55 PM.

  • #2
    How quickly are you going to full throttle? Rolling on the throttle or pedal to metal flooring it?

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    • #3
      Originally posted by iscariot View Post
      How quickly are you going to full throttle? Rolling on the throttle or pedal to metal flooring it?
      Both, I assumed at first my issue was accel fuel enrichment but it does not appear to be so.

      Comment


      • #4
        It sounds like it's too rich then. This was just posted tonight and pretty much says what I was going to post - http://www.miataturbo.net/megasquirt...lp-tune-92145/

        The sum of it is: When you're rich enough to cause a misfire, you pass unburnt oxygen through the motor. The o2 sensor reads oxygen, not fuel content - so when it's "lean" it means there's more oxygen than stoich.

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        • #5
          Originally posted by iscariot View Post
          It sounds like it's too rich then. This was just posted tonight and pretty much says what I was going to post - http://www.miataturbo.net/megasquirt...lp-tune-92145/

          The sum of it is: When you're rich enough to cause a misfire, you pass unburnt oxygen through the motor. The o2 sensor reads oxygen, not fuel content - so when it's "lean" it means there's more oxygen than stoich.
          Interesting read. I'm excited to go to the shop tomorrow and take some fuel out and see what happens. I never even thought for a second it was too lean, but tonight when I drove it and it almost knocked me out.. I was like dang... this explains a lot.

          Comment


          • #6
            I'm no tuner - but I know my way around megasquirt pretty well. And you're on the right track - I was fishing to see if it could have been tip in (accel enrichment) drowning the spark. I think you're on the right track and the root cause sounds logical - fixing the intake leaks.

            Comment


            • #7
              Originally posted by iscariot View Post
              I'm no tuner - but I know my way around megasquirt pretty well. And you're on the right track - I was fishing to see if it could have been tip in (accel enrichment) drowning the spark. I think you're on the right track and the root cause sounds logical - fixing the intake leaks.
              Back to what that thread said... "I plan to pull THOSE plugs tomorrow morning as soon as I go in and see if they are carbon fouled."

              Well, I've been pretty busy all week machining parts for this year's car, and finally had a chance to sit down and do a little diagnosing.

              First issue I found: the main killswitch for the car, which is required per the competition rules, breaks the battery ground. Probed it with a meter and it showed on average, ~100kohms. Holy crap! I have no clue what the hell was going on with that, but I compared it to the switch on the SP14 and discovered the switch on that car was a name brand Hella switch (which had like 0.19ohms, probably less if I had a better meter) while the one on the KS1 had literally no markings on it. Swapped that out for a brand new switch (Hella). While the car was in some state of taken apart, I decided to check the spark plugs, like I originally planned to.

              Pulled out the plugs, two of them looked like they were carbon fouled (cylinders 2/3) and the other two looked.. brand new? Almost like no combustion was even happening. I thought about it for a minute and decided the only thing that would lead to that would be... spark not occurring on those two cylinders or compression issues (not sure if this would actually cause that, but compression is good anyway so I ruled that out) or injector problems. I know spark is there, so....

              Took the injectors out of the intake manifold, threw together a slightly ghetto setup to check the spray patterns, these videos are the results...

              https://www.youtube.com/watch?v=I5lTfQpniFM

              This injector is literally just not atomizing fuel whatsoever.

              https://www.youtube.com/watch?v=IHtAzGSoO4A

              And this one... hardly dribbling out any fuel at all. Both of these were, of course, tested at full prime, operating pressure.

              I cannibalized some injectors from the other car, and after testing them to make sure they were good, threw everything back together. I actually emailed an alumni asking for a copy of "the best tune we've ever had" and went ahead and uploaded that to the car, checked my sensor calibrations, and took it outside to hopefully hear it run right for the first time, ever...

              https://www.youtube.com/watch?v=Ik23A3_lewQ

              Here it is idling...

              https://www.youtube.com/watch?v=nrJfag7t3kI

              And here I am having a tiiiiiiiny bit of fun with it.

              I'm extremely excited to finally have this car running right-ish...

              Thanks for the help guys!
              Last edited by twolf; 02-18-2017, 12:07 AM.

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              • #8
                Nice! And you learned an important lesson - your sensors will have ground offsets, your logs can lead you astray - but your plugs were what previous generations tuned by and they almost never lie.

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                • #9
                  Originally posted by iscariot View Post
                  Nice! And you learned an important lesson - your sensors will have ground offsets, your logs can lead you astray - but your plugs were what previous generations tuned by and they almost never lie.
                  Plugs tell a lot. It's definitely something anybody who is interested in cars should be exposed to. In fact, when the team "freshman" joined this semester, I gave them all links to pages about "how to read spark plugs" haha.

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                  • #10
                    https://www.youtube.com/watch?v=w1yQgh2tpL4

                    Don't think this has ever happened before, but we actually have not one... but TWO! running cars!

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