The ionisation knock detection technique is very clever and accurate but at the same time requires a great deal of processing power, I believe the ECU has a very powerful DSP chip on board.
From the article, you can see how the controller was able to recover after receiving a large change in frame-front propagation speed due to the humidified air.
You would equally be impressed how the system also copes well with water injection rate beyond 25% w/f ratio!
See the link below:
http://www.aquamist.co.uk/dc/coollin...ess/press.html
Such a shame that the WI never made it to the productin line. :sad: