Smoke control is done by a custom motherboard with logic and triac smoke drivers. That's why you need the special secret handshake to turn on and off the individual smoke units and not the standard smoke controls. You can see the logic in the middle and the triacs on the upper left corner. That's the one part I see on these that would be very difficult to replace with any substitutes as they're no longer available. I managed to snag a spare for my engine before they were gone.
