Coil on Plug Ignition System - Test run with datalog

Discussion in 'Electrical and Ignition' started by KitCarlson, Nov 12, 2016.

  1. KitCarlson

    KitCarlson Well-Known Member

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    I have been working on a Coil-On-Plug ignition system for over a year now. I started from scratch, and only have a limited time to work so it has taken a long time. There is a thread here that covers the initial development process. It is long, and not a good read even if you are a technical person.
    COP Ignition Development
    Here is the test route, show in yellow marked on map:
    IMG_20161111_215446.jpg
    Here is the the RPM data vs drive, at 0.2 second intervals. The total plot is 4321 intervals or about 14.4 minutes. All the other data is also collected coincident. The test drive was in traffic at speeds mostly 40 MPH and 45 MPH, with one short kickdown burst, from about 10 MPH to just over 50 MPH.
    RPMlog.jpg
    Here is the plot of ported absolute pressure at the timed carb port. Absolute pressure in hPa, is different than vacuum, or gauge pressure, but conversions are possible if that matters. 1000 is close to standard pressure, in thinking of vacuum that is no vacuum, what would happen if you pull the hose. Zero would be very high vacuum, but 271 is close to 8"hg, 338 10"hg, 457 13.5"hg, 508 15"hg. High pressure happens when throttle plate is closed, or WOT.
    APPlog.jpg
    And last the ignition timing that is associated the RPM, and the APP. The Total Advance is "Base Timing" + RPM Advance + Absolute Pressure Advance". The Base Timing is what is set at the distributor using static method, using timing light at idle with mult-strike disabled, and advance control at zero.
    TimAdvLog.jpg
    The green shows the total advance. Blue is RPM or mechanical, red is pressure or what is commonly vacuum advance. For those that think vacuum advance is for babies, imagine removing the red. The light throttle driving in most of this drive, show that the vacuum component is just as important as the RPM advance.

    I have the plot data and plots on Open Office Calc .ods format. Dropbox - b66testrun_wPlots.ods The data makes more sense if the plots are overlaid, so advance is easily noted vs RPM and pressure. To show here it might more confusing since the Y axis scale would need to represent RPM, and Advance numbers on different scaling factors.

    There is less than a mile of driving show in log, not on map at speed below 15 MPH.
     
    Last edited: Nov 12, 2016
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    • rednesss

      rednesss FABO Gold Member FABO Gold Member

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      How did this turn out?
       
    • KitCarlson

      KitCarlson Well-Known Member

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      It works great! I made a few changes after my last post. I found a math error that resulted in a granularity of 5 degree steps in timing, fixed that. I transferred the newly developed timing controls for idle stabilization/starting to my efi/ignition system on my kitcar. I stored the COP ignition in a box, put back the Mallory Uni-lite. The ignition felt out of place on otherwise stock 66 Barracuda.
      I spend my time babysitting a grandchild. I have not worked electronics for about 18 mo. I missed it at first. I worked electronics non stop for about 50 years. Not sure if I will get back in.
       
    • 67Dart273

      67Dart273 Well-Known Member

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      It will be a great loss if you don't, Dave. What you posted here is somewhat over my head
       
    • KitCarlson

      KitCarlson Well-Known Member

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      I am getting out at the top of my game. Babysitting consumes most of my time, but it is very rewarding. Check out this YouTube. At 18 mo he knows how to assemble nuts and bolts, and is very mechanical.