What about substituting a bosch knock sensor in place of the mic?

 

Possibly, but they are less sensitive than a microphone (typically) and so the amplifier module would need more gain.

I guess you would have to experiment and see what result you get.

 

Not all knock sensors are created equal. They have different natural resonant frequencies. Their natural resonant frequency can be found by using an adjustable sine wave generator and a fullrange speaker. Simply sweep the frequency range on the sine wave generator and record the knock sensors output voltage. It will register the highest reading at its natural resonant frequency.

Depending on the engine size and characteristics, the frequency range where detonation can be heard may vary. For this reason, they tailor the knock sensor range to be most sensitive in this area. This is usually combined with high-pass/low-pass filtering in the ECU so it blocks out frequencies that do not want to be heard.

-Jamie

 

Sorry, I should have specified the flat response one's.

 

The setup I completed the other nite. Hoping to get a few minutes to put it on this week and test it out, car has been acting weird not wanting to take hardly any timing, something seems awry.