ECU CAPABILITY

[Ben C34]

Oh, so the voltage being displayed is via a cheap volt meter wired in?

my suggestion, and I could be wrong and don't want to offend you, is that may be wired into the wrong pins. Don't take that as a negative or having a go, sometimes going back to the start / basics is what has to happen. The whole 2.4 volts thing has confused everyone except you, because you have seen it and did it. Everyone else's knowledge of a knock sensor doesn't match your experience, and that is why you are getting a bit cranky..

But a knock sensor is a simple thing, understood by many, that doesn't put out a voltage. So something is up, which has impacted this thread in a big way. Can you confirm what pins you connected to?

 

Also, proper terms seriously matter, you can't just use different terminology that may be conflicting or not make sense then tell people to just accept it and move on.

 

[Ben C34]

Hang on, have you connected the meter with one lead to positive and one to the knock sensor? Quick diagram please

[Slap]

Thank you for being decent this post ben.

I will check the pins again and will check the wires for any previous modifications.

Yes terminology. Im not great with it and does me no favours when explaining to people who know the exact terms.
Why i stated i wont be using it and that you guys are smart enough to decifer or re-correct me.

I do remember reading about it back in the day.
Just cant remember enough.

Ill post back up the pins there on.

[Dose Pipe Sutututu]

You need an oscilloscope not a voltmetre to determine knock, a knock sensor behaves very similar to a microphone.

Like I said in a previous post, if you test the voltage on the knock sensor pin without the sensor connected you'll detect a voltage when using a stock ECU.

[Slap]

Ok the thing is dosepipe. I know that.
I just couldnt get across that i cant and havent - and i have volts.
I remember reading that it was useless but id already wires it up.

The wires seem correct pins 23 and 24.
Off white almost cream wires as in the pic.

Geebs i havent dove in there for a while hecticly taped and messy. Needs a tidy up.
Ahahaha dont get sus i know theres wires everywhere i did most of em , and i just broke one with the tape lol. Easy fix.

Former owner did safc as standard install with gtr injectors when i bought it back in 2013. Ok for e85 hahaha.
There is also some hacking from b4 2.

What is thar brown plug with all the wires. Is it to do with the wire shielding?

[Slap]

Pics

[Slap]

I cant see the pics

[Ben C34]

Pics worked.

 

[iruvyouskyrine]

This is the most pointless exercise ever, and i love it. 

I couldn't have even dreamed of anyone trying to measure knock with a jaycar multimeter.

Also love your 20/20 hindsight knowledge. Everything anyone posts you 'already knew'.

Good luck figuring it out!

[admS15]

I've learnt heaps from this thread, please carry on. Slap is the the man.

[OBJEXX]

Consider me entertained 

[burn4005]

holy f**k Slap you did not take my advice.

the knock sensor is a microphone. it generates an AC wave. that is the sound of the motor. taller wave = louder. spacing of the waves = frequency. its not a DC voltage. a sound wave can have many many many frequencies. it is continuous, not discreet. you only care about noises in the frequency range the engine vibrates at when it knocks.

a decent ecu will filter that noise to a particular "band" of frequencies (say 6-7khz). the peak Amplitude of that signal is your knock level. it can be in volts, it can be in ADC counts. if your engine is not knocking it will be quiet in this range. LOW VOLTAGE. if it IS knocking it will be loud in this range HIGH VOLTAGE.

a shit ecu will not filter the frequency, which is ok if your sensor is resonant to your engine knock frequency. but for a wideband sensor.

the voltage you are reading will be the PEAK voltage seen by the ecu, and probably have a peak/hold circuit that gets reset after a delay. now for this to be useful, you need to know:

is your sensor wideband or resonant?

does your ecu do bandpass filtering on that signal?

the voltage you are looking at is an indicator of the VOLUME of the noise the knock sensor (microphone) is picking up. that is NOT usefull if you have the following:

wideband sensor with no bandpass filter (this will be all the engine noise)

this IS useful under the following:

wideband sensor with bandpass (this is knock frequency only)

resonant sensor with or without bandpass (if sensor is resonant to the frequency your engine knocks at)

if you want to know how LOUD the signal is, you can use a peak/hold multimeter. this will just tell you maximum volume, it could be at 100hz or 15khz. it won't tell you about knock.

if you want to know what FREQUENCY the knock is occuring at you will need a scope. you need both the frequency and amplitude of the signal to work out if its actually likely to be knock or just loud noises at frequencies you don't care about.

 

to understand what is happening you really need to plug the knock sensor into a usb soundcard and use some spectrogram/ real time fourier (frequency) graph software. something like this: https://digh.com/product/deka/

 

some free software I use is this which works great.

http://www.sdradio.eu/weaksignals/spectran.html

 

 

 

 

Edited March 6, 2019 by burn4005

[89CAL]

* Waits for "I know this* Response then reply asking about why there is voltage there *

I am not sure how this is taking so long to understand, especially with some smart people giving some smart answers.
I feel like you have backed yourself into a corner and now just want to attack everyone saying your wrong rather then admitting that you made a mistake and you now have been given some knowledge.

If you really want to get some information out of the knock sensors, something like the below may help:

Ebay Oscilloscope

[RICE RACING]

It's just like an episode of Bold and the Beautiful, except there are no hot chicks.

[burn4005]

Quote

So you are saying the voltage is manipulated to bend in amplitude according to vibration causing it to become a frequency. Not changing volts.

Would the voltage displayed be the threshhold in wich the frequency works at.

why does the voltage drop on e85? Less noise? Less frequency needed? Magically? or im full of shit and it doesnt wich makes no sense to my eyes that have witnessed it ?

Anolog is as simple as a boost switch or bleed valve.
And i know it needs a digital tune to make the most. Geebz nearly any mod manualy controled or manipulated is anolog tuning.
The anolog gauges are just a unique trend . 

this is one of the dumbest f**king things I've ever read.

the only thing that might make sense here is you are actually Japanese and are running all your answers through google translate into english. 

the reason you are being attacked is you have been unable to convey any coherent concept whatsoever but are still somehow attempting to claim the intellectual high ground here.

Edited March 6, 2019 by burn4005

[GTSBoy]

24 minutes ago, burn4005 said:

the only thing that might make sense here is you are actually Japanese and are running all your answers through google translate into english.

Maybe you should run it back and forth through google translate between Japanese and English until it starts to make sense.

[Slap]

holy f**k Slap you did not take my advice.
the knock sensor is a microphone. it generates an AC wave. that is the sound of the motor. taller wave = louder. spacing of the waves = frequency. its not a DC voltage. a sound wave can have many many many frequencies. it is continuous, not discreet. you only care about noises in the frequency range the engine vibrates at when it knocks.
a decent ecu will filter that noise to a particular "band" of frequencies (say 6-7khz). the peak Amplitude of that signal is your knock level. it can be in volts, it can be in ADC counts. if your engine is not knocking it will be quiet in this range. LOW VOLTAGE. if it IS knocking it will be loud in this range HIGH VOLTAGE.
a shit ecu will not filter the frequency, which is ok if your sensor is resonant to your engine knock frequency. but for a wideband sensor.
the voltage you are reading will be the PEAK voltage seen by the ecu, and probably have a peak/hold circuit that gets reset after a delay. now for this to be useful, you need to know:
is your sensor wideband or resonant?
does your ecu do bandpass filtering on that signal?
the voltage you are looking at is an indicator of the VOLUME of the noise the knock sensor (microphone) is picking up. that is NOT usefull if you have the following:
wideband sensor with no bandpass filter (this will be all the engine noise)
this IS useful under the following:
wideband sensor with bandpass (this is knock frequency only)
resonant sensor with or without bandpass (if sensor is resonant to the frequency your engine knocks at)
if you want to know how LOUD the signal is, you can use a peak/hold multimeter. this will just tell you maximum volume, it could be at 100hz or 15khz. it won't tell you about knock.
if you want to know what FREQUENCY the knock is occuring at you will need a scope. you need both the frequency and amplitude of the signal to work out if its actually likely to be knock or just loud noises at frequencies you don't care about.
 
to understand what is happening you really need to plug the knock sensor into a usb soundcard and use some spectrogram/ real time fourier (frequency) graph software. something like this: https://digh.com/product/deka/
 
some free software I use is this which works great.
http://www.sdradio.eu/weaksignals/spectran.html
 
 
 
 

Voltage explained!

And the rest of you trolls spittin shid like your skyline preists can go lik an arse.

You couldnt answer it and thats that . You went on about everything else making me confused as shid.
And maybe when ur intelectual abilities extend beyond the bible of tuning and mechanics you might actualy understand what i said , where i was confused , why it was said, and why a lot of what you have posted is erelevent to not only the point but to me. Because i dont dyno tune or have sufficient consult equiptment.
As i stated i know it isnt usefull and asked why i see it. Wich atleast was answered by someone with intelect and wisdom.
Not a load of shid about its impossibleness.

[Ben C34]

[GTSBoy]

[RICE RACING]