Detect knock before your knock sensor can.

[H@xtGSX]

I love reading the Autospeed website and came across this a while back and decided to try it.

http://autospeed.com/cms/article.html?&A=0353

It is basically a way to make an amplified headset for listening to engine noises that you can comfortably use while driving. You can hook the clip up to the block and you really can hear the pinging before it even registers a single count of knock in the ECU. Real knock is EASY to hear and very obvious with this. It makes an odd "ker-THAP" kind of sound. It's unbelieveably useful and if you don't have a way to log knock, this is a god send for tuning without a logger.

Autospeed is absolutely jam packed with good info. Great site.

 

[mattasi]

Wow... That's pretty cool.

 

[H@xtGSX]

I thought so. It really works too. You don't have to get that "Whisper 2000" thing either. Most of those little amplfied listening units work the same way. I have seen similar type devices used for chassis tuning also. Pretty useful gizmo for not much money... perfect for us.

 

[huafist]

That's one of the neater DIY detcans I've seen. Most are just nylon hose epoxied into a set of headphones.

 

[91talontsifwd]

I actually made one of these setups a little over a year ago, and I use it to detect knock in conjunction with my MSII megasquirt fuel management system. I even have the jack able to go directly into my radio head unit, and I can hear the knock sensor through my speakers in my car, or have the option of running through headphones. It does work great, haven't had any problems with it.

I believe you should be able to just run the knock sensor wiring to a headphone jack, and have a jumper that plugs directly into the front of an aftermarket headunit, and the headunit should amplify the sound on its own.

 

[My1GLaser]

Isn't the 4G63 knock sensor an electronic microphone? It has a hole in the end and I could have sworn that I have read on here that it is a microphone. To the degree that some people have rtv'd or jb welded over the hole cause it is supposedly too sensitive...

 

[greekgodchaos]

Very good site! Just came across an article on how Mitsubishi developed the Vortex Generators for the Lancers Linky

 

[H@xtGSX]

I just finished reading about the Lancer vortex generators also. I love autospeed. They are extremely ingenius Australians. Plus, they make their projects sound fun... I am going to call my trunk a boot now.

I actually made one of these setups a little over a year ago, and I use it to detect knock in conjunction with my MSII megasquirt fuel management system. I even have the jack able to go directly into my radio head unit, and I can hear the knock sensor through my speakers in my car, or have the option of running through headphones. It does work great, haven't had any problems with it.

I believe you should be able to just run the knock sensor wiring to a headphone jack, and have a jumper that plugs directly into the front of an aftermarket headunit, and the headunit should amplify the sound on its own.

If that is the case, could you splice into the knock sensor and have it feed both an audio monitor you could hear in the cabin and the ECU without compromising its function in the ECU monitoring?

 

[PieEyedPiper]

I badly want to make one of these.

 

[H@xtGSX]

I badly want to make one of these.

Well, what's stopping you man?! Get to it! It's dirt cheap and awesome!

 

[H@xtGSX]

Here is what I bought. You can get these at most Radio Shacks, but check first. I had to check several, but it is worth it, and I will tell you why...

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These have 2 mics to produce stereo sound. One mic per ear. The nice thing with this is you can mount one clip on one end of the motor and the other on the opposite end. This can help tell you if knock is occuring more in one bank of cylinders more than another. Here is a pic showing where the 2 mics are and what they look like.

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This is what else I had to buy. 22 or 24 ga wire, shrink wrappers, a few connectors to make routing wires easy if you plan on leaving it in place a while, and a couple battery clips. You'll want to solder the connections, so you need that stuff too.

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After soldering on the extension wires and 60 second epoxying the mics to the clips, making sure to shrink wrap and cover bare conductors, this is what I have now. Mine cost about $38 total, so a bit more that the Autospeed site version, but essentially the same except stereo for 2 points of monitoring.

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I have used it, and it is better than any knock sensor could hope to ever be. When you hear "bacon sizzle", you are hearing knock, and you'll hear it much sooner than the knock sensor does. It starts out as a quick "Thap thap thap" noise and then progresses to the sizzle noise, which will be LOUD by the time the knock sensor starts pulling timing. It is extremely easy to pick out from the normal engine hum.This is well worth the bit of time it takes to make.

 

[boost97gst]

im making one asap! Thank u so mch for posting that link, u rock dude

 

[wishihadatalon]

My setup just runs from the stock knock sensor into my line in on my laptop and I run head phones out. Seems to work quite well. I can also record the audio with the windows sound recorder so I can run it at the same time as I view my logs. It works quite well though I wish I could cancel out a few frequencies to reduce some noise.

 

[H@xtGSX]

My setup just runs from the stock knock sensor into my line in on my laptop and I run head phones out. Seems to work quite well. I can also record the audio with the windows sound recorder so I can run it at the same time as I view my logs. It works quite well though I wish I could cancel out a few frequencies to reduce some noise.

This is one of the downsides I have noticed also. You will hear all of the other noise the engine makes with this device... Lifters tick, injectors tick, belts whirr, gears whine, and even turbulence in the intake. You will be able to hear all of it, loud and clear. Still, you can quite easily catch the tink-tink-thap of knock over all this. The trick I have found to using this listener is to position the clips lower on the block. I can't easily stick my arm down and clip to anything protruding off the block near the knock sensor, but the edges of the block down low work also. I haven't clipped to the front because I am afraid the exhaust heat will melt the epoxy.

 

[tkelly27]

I used the laptop I was tuning with to amplify the sounds. A friends car was getting CRAZY knock over 3k and pulling timing badly. Turns out it was a clacking lifter. We disabled the knock retard and the car was hauling booty again.

You can also get a lot closer to tuning properly by determining where your car will knock at a given RPM without any boost. Unhook the can from the WG flapper and push the timing until knock. You can then pull it back and get a feel for where your peak torque is. Then you can add a small amount of boost back in and see how boost changes what kind of spark timing your engine wants as you add boost. Not as good as a dyno, but it is much better than shooting in the dark and adding timing until you get knock at 30psi. Be super careful on pump gas with this method too. Go nuts with E85!

 

[H@xtGSX]

I found out mine knocks like crazy at 2500 to 3000 if the gear is too low. The high load and low speed make it knock a lot more than I would have expected. It also suggests my base timing may be too high.