pre-ignition

[Evernden_Wes_A/lcs_system3 at system3.lcs.gov.bc.ca]

I believe that Toyota used knock detection on one of their Japanese 
models. The detector was a piezo-electric washer that replaced the 
normal spark plug washer. I can't remember much else, I think i read it 
in SAE magazine or in a paper. I'll keep my eyes open for it.

Wes Evernden (not a student, anymore)
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Back to real stuff:  One person replied to my post about pre-ignition
detection, saying that it showed up from 5-8khz.  What sort of detector would
work to pick up this signal?  piezo-electric tape is easy, just stick it on,
but it might have problems with the heat, and it may not have the correct
frequency response.  how about commercial detectors?  are there sources for
them, how much do they cost, and can they be easily interfaced?  once a
detctor is found, what is the control algorithm for the ignition?  the
simplest seems to be to continually advance the ignition until pre-ignition is
detected, then retard it a little.  would this give the most power?  or is
more feedback required, like maybe an exhaust monitor?  inquiring minds want
to know....

Those of us who are still here, lets keep the list going.....

--steve