古惑強

Yes indeed, it is compatible with Marelli ECU (which is used in Lancia & Coupe 16vt) as well.  However upon this type of conversion in the oldie Sierra Cosworth Engine, you still can not dynamically alter the ignition timing as the older ECU does not support that function.

古惑強

In a 4 stroke 4 cylinder engine, 2 associate cylinders will always be moving in a synchronize mode, one in compression / ignition mode and the other in Nil energy mode.  A waste spark system basically is wired towards these 2 cylinders together and will ignite no matter whether they are in Energy mode or in Nil mode, so 1 out of the 2 sparks is always a waste.

Pros - cheap, for 4 cylinder engines, just 2 ignition coil systems are required instead of 4.
Cos - ignition coil output capacity x 2.