Seeing this knock sensor on the Turbo II brought to mind
about what I was going to do about it. Seems to me one way
of approaching an automatic ignition retard is use a separate
PIC computer that passed through the ignition pulse if there
were no knock. As soon as knock was detected it would delay the 
pulse by an amount depending on the RPM thereby retarding the ignition.

The analog circuit could be as simple as a comparator with a sensitivity
pot. You set the pot until an LED on the output of the comparator 
just goes out under normal operation. If the voltage from the knock 
sensor exceeded that threshold the dedicated PIC knock processor 
would then delay the ignition pulse. Another output from the PIC 
could open the waste gate to simultaneous reduce the boost.
This way Tracy would not have to reprogram his EFI computer 
to add knock capabilities. There may be something like this on the 
market already.

There is an issue however and that is; do you want a computer to
automatically  reduce the power just because the engine happens to knock 
while executing a critical takeoff maneuver? Incidentally a highly likely time
for it to happen.

Another possibility is have the knock computer inject anti detonation fluid.
This option makes the most sense to me.

Paul Lamar
 
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