I stumbled upon one of those ignitions on a Saab 900 Turbo, mabye like a '96 model or something.
As I understand it, the ECM commands each coil pack to apply 80 volts to their corresponding spark plugs during a compression stroke. If that current finds continuity to ground, then ionized gasses are present within the combustible mixture, and detonation will be eminent. The firing event is delayed until closer to TDC so the flame kernel can expand while dynamic compression drops as the piston travels downward, instead of expanding as dynamic compression rises as the piston reaches TDC.
If that were applied to a VW, full engine management would be nessesary. It would have to use a crank triggered ignition, and sequential DIS ignition (not a waste-spark two coil type) with a cam sensor. The ECM would have to be able to sense a voltage drop in the secondary ignition circuits individually (4 in all) and quickly delay firing if the voltage did drop at that plug.
Imagine the benifits in a turbocharged engine. That could make a turbo Type IV feasible in essentially a bolt together kit!
