Can I get a wire diagram for an 8 pin HEI Please (Thanks Pishta)

Electrical and Ignition

  1. TrailBeast

    TrailBeast AKA Mopars4us on Youtube

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    I'm pretty sure I have it down, but would feel better about it if I had a proven working diagram for the GM 8 pin HEI module and E-Coil installed in place of the original Mopar stuff.
    The main reason I want to use the 8 pin is that I would like to look into being able to change the timing advance on the fly for elevation changes some day down the road.

    Thanks

    This is what I have so far to do the changover.
     

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  2. Bulldozer

    Bulldozer free ice cream sandwiches

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    you got goodies lol heres a bump for you.
     
  3. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    Bill Grissom is the guy for those on here
     
  4. TrailBeast

    TrailBeast AKA Mopars4us on Youtube

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    Thanks, I'll wait and see if he is up to it.
     
  5. Coronet 500

    Coronet 500 Well-Known Member

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  6. pishta

    pishta I know I'm right....

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    [​IMG]

    [​IMG]

    any help?
     
  7. TrailBeast

    TrailBeast AKA Mopars4us on Youtube

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    OHHHHHH
    Just what the doctor ordered.

    Adjusts base and total timing.
    Adjusts the timing curve.
    Retards timing with boost.
    Allows in car changes in the timing.

    All electronically through the GM HEI module. [ame]http://rabidgator.com/support/GM_HEI_TimingComputerInstructionManualVers1_0.pdf[/ame]
    That saved a lot of work for me.
     
  8. TrailBeast

    TrailBeast AKA Mopars4us on Youtube

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    Exactly the confirmation I needed, thank you so much.
    Did you happen to see the link that I posted above?

    It's a miracle. :blob:
    I'm ALL exited now.

    Again, thank you.

     
  9. pishta

    pishta I know I'm right....

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    Wow, this is pretty f'n cool! Might be the cats ass for my turbo slant!
     
  10. pishta

    pishta I know I'm right....

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    how much is this doodad?
     
  11. TrailBeast

    TrailBeast AKA Mopars4us on Youtube

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    Chking now.

    Damn, they must be really new.
    Thier website isn't functional yet, and they don't come up on Ebay like the website says.

    So far only a phone number on the website.
    None of the links or supposed hypertext images linked to the software or payment work either.
     
  12. TrailBeast

    TrailBeast AKA Mopars4us on Youtube

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    So far I still have not found a price on the computer control guage anywhere.
    Almost afraid to call and ask how much it is and start saving now.
     
  13. BillGrissom

    BillGrissom Well-Known Member

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    pishta's post looks good. I got my info on the 8-pin from the megasquirt site (search "8-pin HEI" on google), which might be where he got the images.

    Here is how simple the wiring is:

    The 2-pin Metripak connector goes to the GM coil, using their factory cable. The thick red wire at the coil gets +12 V ignition. The white wire is tachometer output (so thick?). Connect the little spade terminals (P & N) to the Mopar distributor wires. Ground the module with a dedicated wire and put it on a heat sink, using thermal paste. Done.

    Somebody cut your coil cable (why?). Good that they snipped the little white connector from the GM pickup. It latches to the module, but is not weather-sealed. A fancy heat sink isn't needed, a simple aluminum plate should work, judging from where GM put the module.

    You can leave the 4-pin connector open until needed for computer spark control. Do get the connector and install to keep out dirt, isolating each wire w/ heat shrink. It is standard GM practice to remove it during testing. I understand it simply gives no spark advance when open, so your distributor then provides the advance as normal.

    Note I didn't tell you the polarity of the distributor wiring. I haven't run my 8-pin on my 64 slant yet, so don't know. I understand it will spark way off the mark and a bit erratic if the polarity is reversed. I'll post back when I get there. Not even working on my 64 right now (84 M-B this week).

    You don't need to worry about the 4-pin spark control wiring if you use Holley's Commander 950 ECU (as I will), since it has an (optional) adapter cable direct to the 8-pin. It is given by comparing the 7 and 8 pin modules pishta shows.

    I would like to know the price of the rabidgator spark controller. I lucked out and got the Holley ECU (alone) for $120 on ebay. I will try spark control when I go EFI on the slant. The rabidgator would be great for those using a carburetor who don't want to fiddle with weights and vacuum advance, plus get a more custom spark curve control. I expect you can leave the weights and vacuum action and have the controller just add to those. That is my plan, so I can bypass it on the road, if needed, and run a regular spark without just a "limp home" fixed advance.
     
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