Any clips of how knocks sounded like on a EJ motor?

[kgb]

Or it entirely depends on the block? I have never heard knock or detonation before and without an aftermarket knock sensor, what is the best environment to do tuning under so that I can actually hear it over the turbo and the exhaust? Will I instinctively know that the engine knocked? The other way is to hook up an SSM-based scanner thru the OBD-II port and read the knock counters off the stock ECU but I don't have one...

Thanks for the help.

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[akira02rex]

You should be able to hear it! It sounds like a thump on your engine as if someone hit it with a hammer.

Remember though, these engines produce somewhat high knock READINGS. What may seem like knock based on reading values, may not really be knock.
If you can get access to a datalogger that reads knock values, not so much knock COUNT, that is very helpful. A big step in a knock reading is usually knock. I get knock readings all the way up to 80 or so but its a smooth transition all the way up there so it's safe.

[mcowger]

At high RPMs it can sound like BBs rattling in a can.

[kgb]

Hmm... that sounds like it will be tough to spot - I don't really have tools have read the factory knock sensor (ie SSM scanner).

[WRX-Blue-Mica]

Knock sound of EJ motor with detcans. Hope this help.

http://ken-gilbert.com/wrx/knock.wav

[Rokkit]

uggg, if you have exhaust, you prolly cant hear jack up on the highway unless its BAD - if you got some engine management i know the utech flashes the CEL when theres knock

[bboy]

Originally Posted by mcowger

At high RPMs it can sound like BBs rattling in a can.

That would be excessive knock. Long before that, you'll hear only occasional knock. To me, detonation sounds like a tight string being plucked. It's a high pitched sound that is damped. To me, the BB analogy is good too, but the pitch is too low. Hold a quarter in one hand, and strike it with another. That's pretty close.

[kgb]

Originally Posted by WRX-Blue-Mica

Knock sound of EJ motor with detcans. Hope this help.

http://ken-gilbert.com/wrx/knock.wav

I hear some blip right in the middle of the clip - was that it? Guess I have to have some tools as the common concensus is that you can't hear unless it's severe

[WRXskeet]

its all that crackeling in the whole clip

[rac]

Any small audio amp and some headphones connected to a knocksensor on the engine will work fine.
I use this very cheap .5Watt amp powered by a 9volt battery with some headhpones and it sound just like that that sound clip above. It sounds like someone flicking the back of the headphones.
http://www.dse.co.nz/cgi-bin/dse.sto...uct/View/K5604

[ride5000]

it's generally a sharp click or snap. in the above clip on my website (which originally came from turboxs btw) it starts about halfway through and knocks a LOT. if your engine management is doing its job wrt knock detection you will hear ONE click and that's it...i know that's exactly what my utec does.

ken

[WRX-Blue-Mica]

Originally Posted by ride5000

it's generally a sharp click or snap. in the above clip on my website (which originally came from turboxs btw) it starts about halfway through and knocks a LOT. if your engine management is doing its job wrt knock detection you will hear ONE click and that's it...i know that's exactly what my utec does.

ken

I got that link from you right? Thanks

Ride5000 ... would you please share your Utec knock treshold numbers? Thanks a lot ...

[WRX-Blue-Mica]

Originally Posted by kgb

I hear some blip right in the middle of the clip - was that it? Guess I have to have some tools as the common concensus is that you can't hear unless it's severe

revise:
you are right, knock happened in the middle of the clip.

[kgb]

So technically you can just tap off the stock Knock sensor, put it through an amp and hear it yourself?

[mcowger]

Originally Posted by bboy

That would be excessive knock. Long before that, you'll hear only occasional knock. To me, detonation sounds like a tight string being plucked. It's a high pitched sound that is damped. To me, the BB analogy is good too, but the pitch is too low. Hold a quarter in one hand, and strike it with another. That's pretty close.

Absolutely correct. I heard it that way on my car on a 100 deg. day after sitting with crazy heatsoak and doing a 80MPH WOT pull while tuning/logging.

I'd never heard it that bad, scared the **** out of me.

[ride5000]

Originally Posted by WRX-Blue-Mica

I got that link from you right? Thanks

Ride5000 ... would you please share your Utec knock treshold numbers? Thanks a lot ...

looking at the raw params files, i get:

115
110
105
101
95
84
75
70

iirc they're all about +5 over default values. i pull 1.5 degrees on a 2 count of knock, max of 15 degrees pulled, duration 100 crank cycles.

hth
ken

[shwaggin]

If you feel so inclined, you could always buy or borrow a Tactrix cable and use Tari DL1 to do logging. You would need a laptop, and obviously you couldn't plug anything else into the OBD2 port while using it. That solution would set you back $70, but if you're worried about not hearing the knock it's an option.

[kgb]

Is this an SSM solution? OBD-II can't read the knock sensor right?

[shwaggin]

Originally Posted by kgb

Is this an SSM solution? OBD-II can't read the knock sensor right?

Yes, Tari DL1 uses SSM. Check out http://forums.nasioc.com/forums/showthread.php?t=774757, http://openecu.org, and http://www.tari.co.za for more info.

[Greenracer6]

Anyone have any fresh ideas on this??

A guy from Indianapolis had a simple setup where he wired his knock sensor to his stereo on a switch, then he just turned up the radio!!!!

Anyone know how to do this????? Thanks!! We could all use a knock radio!

[subydude02]

i'm gonna give this a shot: http://www.d-series.org/forums/diy-f...5-dollars.html

[scoobystas]

^^^ i've made one of those setups. It gets really loud, especially under wot. There is so much going on that for me, its hard to differentiate what is valve noise, what is piston noise. Can't say i've ever heard knock using them, but i've only used them about 4-5 times since i've made it.

[ride5000]

Originally Posted by Greenracer6

Anyone have any fresh ideas on this??

A guy from Indianapolis had a simple setup where he wired his knock sensor to his stereo on a switch, then he just turned up the radio!!!!

Anyone know how to do this????? Thanks!! We could all use a knock radio!

i use a tuner pro to do that.

according to txs, the tuner pro does employ a high pass filter to help differentiate the racket. it also uses a real knock sensor bolted to the block.

i can say that through the HPF of the tuner pro, knock sounds like a sharp crack.

above 4k rpms or so things do get pretty noisy, so you have to listen closely. although i have a cassette tape adapter hooked up, the best way to monitor, especially when setting thresholds, is through headphones.