Is it possible to monitor the oem knock sensor on the s2?

[S2central.net]

No need - the knock sensor is essentially a microphone...

[a4kquattro]

quattro84: yes it is actually very easy in my opinion to pick up knock. its occurs in the 6khz range and is an irregular event, easily picked up in the audio file by the naked human ear. Usually when I use this tool for dyno tuning I start by recording audio from the car under low load on the dyno spinning the rollers in gear to redline. I use this as my baseline to compare full load audio runs. Its extremely easy to pick up discrepencies in sounds between the baseline and full load runs. This is extremely useful, since all exhaust and turbo noise is completely erased: only mechanical noises are recorded by the knock sensor.

Example of a 'clean' pull, no knock: http://www.theswansonfamily.us/modul..._s6_onramp.mp3

and here is a dyno example where I encountered knock on a customer car (quickly resolved!): http://www.efiexpress.com/downloads/...24_seconds.mp3

[S2central.net]

I must get into this sometime - I am frankly amazed how clean the audio is with this method... Does seem that with practise one can hear audible knock with this method. I had always assumed it would be a lot gnarlier and hard to detect with the human hear.

[a4kquattro]

I must get into this sometime - I am frankly amazed how clean the audio is with this method... Does seem that with practise one can hear audible knock with this method. I had always assumed it would be a lot gnarlier and hard to detect with the human hear.

the 'secret' is in using shielded cable and grounding to the engine block. The noise is insane without it.

[A80Avant]

marc does this mean that i have to use one of the factory sensors to do this at a time? take one plug off, plug the mic in and record?

do you use any specific recorder on the laptop,or the windows one?

[a4kquattro]

marc does this mean that i have to use one of the factory sensors to do this at a time? take one plug off, plug the mic in and record?

do you use any specific recorder on the laptop,or the windows one?

yes. I just use windows sound recorder.

You also have the option of bolting a third knock sensor to the block if you wanted to, but I've always just disconnected one of the two factory sensors to record the audio.

[Jamo]

How did I miss this? does it matter if you make the cable which knock sensor you plug into?

[Billman]

How did I miss this? does it matter if you make the cable which knock sensor you plug into?

Search for "knock senor hearing" spelled wrong.

[A80Avant]

i have this cable, works very nice!