MisGen3 Dual Plug Adapter

The Dual Plug Adapter (DPA) box for MisGen3 allows a single Pendant to simultaneously control two distinct misfire boxes connected to engines having two spark plugs per cylinder. If we arbitrarily call one set of spark plugs “Group 1” and the other set “Group 2”, then one misfire box connects in the usual manner to Group 1’s ignition system and the other box connects to Group 2’s ignition system.

Although the type of ignition system for each group of plugs determines which variant of MisGen3 box (CCB or ICD) must connect to it, the DPA (as well as the Pendant) is agnostic with regards to the types of ignitions. In other words, the DPA works with ignition systems where both Group 1 and Group 2 are Integrated Coil Driver (ICD), where neither is ICD, or where one is ICD and one is not. These three scenarios correspond to using two ICD boxes, or two CCB boxes, or one of each.

Of course, the reason for controlling two boxes with the same Pendant is to ensure that both boxes create misfire in their respective spark plugs at the same time. If the two boxes were controlled by separate Pendants – even with the same settings for misfire pattern and rate – there would be no way to synchronize them so that both spark plugs misfired on the same combustion event, because full misfire only occurs if both sparks plugs in a cylinder fail to fire, this Dual Plug Adapter box is needed to achieve that.

The DPA box contains electronics needed to ensure that the software within the control Pendant interprets the signals properly even when the plugs of Group 1 fire at slightly different times than plugs of Group 2, which is often the case. It makes no difference if Group 1 or Group 2 plugs fire first (or at the same time).

Using the DPA is straightforward. There are two male 25-pin D-Sub connectors (“DB25”) on the faceplate, and one female DB25. The two male connectors are joined to the two misfire boxes using the supplied 25-pin cables. The other DB25 connector (female) is for a longer cable to the Pendant. Depending on what types of ignition drivers are used on coils for each Group of spark plugs, in addition to this DPA box users will also need to purchase the proper types of MisGen3 boxes (ICD or CCB) and a control Pendant if they don’t already own them.