How to Megasquirt your 3G Hemi
I just called Matt at DIY auto tune.
He said:
The knock module board is an $85 part
Labor is $75/hour, minimum of 1/2 an hour (said it would take no more than 1 hour to do at the MOST)
*I'm guessing it wouldn't be as much to have it added at the time of building the box
He's not sure if the hemi sensor is an untuned or tuned knock sensor.
I would have to set the knock module for the frequency. Apparently there are a number of calculators you can use to estimate the frequency, but the 'right' way would be to record the readings and play them back through a spectrum analyzer.
He also mentioned to first try the fundamental frequency, and if that didn't work, to try the 2nd. If you aren't getting feedback, you aren't on the correct frequency.
I told him my initial plan was to use a homemade set of knock headphones. Apparently they use a set of electronic knock headphones themselves when they tune, as it is easier to decipher what is and is not knock.
I think for me the right move at this time is to skip the knock module and use the whisper2000 homemade knock headphones to listen for knock. As long as I keep the same grade of fuel (and don't ever get a bad tank of gas), I should be fine. Seems that is the consensus among megasquirt users online as well.