a4kquattro

So I dont trust a lot of the aftermarket electronic knock detection tools out there that blink a light during a supposed knock event. The problem with most of them is that they do a poor job of filtering out perfectly normal engine noise.

So I did some reading on the subject and decided to try something really simple: wire up an adapter harness to a factory audi knock sensor to a standard microphone jack. Plug that into a laptop PC with a set of race style headphones (basically ear protection with a built in speaker, you see them a lot at race tracks) plugged into the headphone jack.

Holy crap, it works perfect! All you hear is the mechanical noises from the engine.. valves opening and closing, lifters clicking, even the fuel injectors opening and closing if you listen close enough at light cruise with throttle tip-in (acceleration enrichment). The noise from the exhaust and turbo are completely muted out, which sucks from an enjoyment standpoint but very cool when you are trying to listen for knock in a dyno room

for those that want to play at home, wire pin 1 to the tip of the mic plug, pin 2 to the middle band, pin 3 to the base. You'll want to run a ground lead t'd to the 3rd pin and grounded somewhere on the engine block as well, this made a HUGE difference in noise reduction.

<img src="http://www.theswansonfamily.us/modules/gallery2/d/57839-1/IMG_1051.JPG">

<img src="http://www.theswansonfamily.us/modules/gallery2/d/57842-1/IMG_1052.JPG">

<a href="http://www.theswansonfamily.us/modules/gallery2/d/57834-1/brian_s6_onramp.mp3">audio clip</a>

fusilier

that sounds like having your ear against a screwdriver on the head.

a4kquattro

except that gets a wee bit unsafe at full load on a chasis dyno

escargot

very cool

UrS4boy

Play the audio clip in Windows Media Player and get a free light show.