Intro - and question

[Andrew H. Voss]

>The question:  I have seen references to the determination of combustiion
completeness 
>and detection of detonation by some sort of feedback through the plugs;
does anybody have 
>the info on this? Thanks.
>

Saab uses this technology currently.  It was developed by Mecel in Sweden,
who were bought by Delco Electronics.  It is accomplished by sensing current
through the spark plug after the spark is complete.  It can't be simply
added to an existing system because the spark burn time is way too long.
That's why the Saab units currently use CD ignition.  We are developing
systems with inductive ignition coils and coil redesign has been a big part
of the effort.  The signal contains a lot of info, but it isn't easy to
extract it from each firing at 5000 rpm.

Andy Voss                 
Advanced Powertrain Systems     c23ahv at kocrsv01.delcoelect.com 
Delco Electronics Corp.         (317)451-0415    GM:8-322-0415

"If you always do what you always did, you will always get what you always
got." - Unknown