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Atomic II & PerTronix Ignitor modules?

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  • Atomic II & PerTronix Ignitor modules?

    I've read over the installation PDF as well as search this forum. So far, I haven't found any specific information if an Atomic II will work with the PerTronix Ignitor modules that replace factory points.

    In my case, I'd like to use an Atomic II on a 1964 Chrysler 300K. This car uses a Prestolite Cast Iron Tachometer Drive Dual Point Distributor. I do not want to replace it. I also do not want to deal with the dual points so I've installed an Ignitor.

    Will an Atomic II work with it or not? Hopefully someone from Holley/MSD can comment definitively. Other then the Ignitor the car is stock. Please advise. Thank You, James

  • #2
    I don't have Atomic 2 EFI, but it's wired with the same inputs & outputs as my Holley Sniper and uses very similar EFI software. Sniper Forums have covered this topic before, but most people buy a complete system instead for plug & play convenience. $$$

    You don't say if you want to control Timing with the Atomic 2, or what version of Pertronix that you have. Holley/MSD does not officially condone using Pertronix anyway.

    If the distributor still controls timing, the Pertronix trigger doesn't matter and things are very simple: The Atomic 2 just gets an RPM signal from the ignition coil negative terminal on its Yellow wire.

    If want to control Timing with the Atomic 2, only the simplest Pertronix Ignitor will work because any variable Dwell and Rev Limiter features will interfere with the trigger signal to the ECU. You must also lock-out the distributor advance mechanisms and phase the rotor to the cap of your Tach-drive distributor. Both are possible, but a little involved which is why most people buy the HyperSpark distributor.

    The key thing about Pertronix is that it grounds through the distributor body, so it's trigger output has only one Black wire (so-called positive signal). Atomic 2 (and MSD ignition boxes) get their ignition trigger "positive" signal on the Purple wire. You'd need to connect the Pertronix Black wire to the Atomic 2 Purple and its Green "negative" wire to Ground (on the distributor body is best) to complete the Pertronix Ignitor trigger circuit input to the ECU. The Atomic 2 then fires the coil on its White wire using a coil driver module (or ignition box). Here's a Sniper-based diagram:
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    Last edited by Candu SNO; 02-08-2023, 04:58 AM.