Knock sensor

[Pete Paraska]

dave.williams at chaos.lrk.ar.us (Dave Williams) replied:

> As chamber pressure goes up it becomes harder for a spark to jump the
>gap.  SAAB might be doing that... but you'd actually have to send a
>spark, which wouldn't be a good idea before the intended ignition event.
>They're probably watching for ionization from detonation combustion.
>The resistance across the gap will change if the mixture is burning.
>                                                                    

I just read in Automotive Industries (AI) annual engine report that Dave is 
right on the money - they are keying to ionization.  They didn't mention how 
they where getting a reading on that, but Dave cleared that up - resistance.
The system is call Trionic Ignition or some such.

Thanks (again) Dave, for giving us the right stuff.

 ~~~~~~~~ Pete (paraska at oasys.dt.navy.mil)          IZCC#15 ~~~~~~~~~