I thought I would post this for those looking to do a street tune before heading to your tuner, which is 8 hours away in my case. I got the idea a while back when I was looking a using an accelerometer (Knock Sensor) and a laptop with a 3.5mm microphone jack to record events. Then through a simple FFT you can analyze the data and make sure there are no problems. As an engineer I should have persuaded that more but I wanted something easier b/c I am sometimes lazy.

This is basically and electronic stethoscope will not tell you optimal timing just help you identify knock before you hear it over your Invida exhaust and dump to.

Basically I bought a amplified stereo listening device, which will allow you to place one sensor on the front and one on the rear of the motor and distinguish between the two to help isolate knock. Then I opened it up and unsoldiered the microphones from the board. Then I added leads between the board and the microphones, this is very delicate work be careful. The next key is to place the microphone against the metal of the alligator clips and epoxy everything in place. After everything has dried all you need to do plug in the headphones or in my case into the head unit and listen up.

Hope this help you.