So I cracked a piston and wanted to see if I could hear any detonation (after it was fixed...lol)
I've read about homebrew ways to listen to your knock sensor, some on here, some on google.
Here is my setup, and a sound clip too!
All the parts for this were bought at radio shack:
Pocket Speaker/Amplifier (277-1008)
9V battery (230-0875)
Mini alligator clips (270-0374)
RCA to 1/8" mono adapter (274-0330)
12ft bare wires to RCA mono plug (420-2372)
1/8" mono to 1/8" stereo jack (274-0882)
Headphone volume control (420-2559)
And you will need some headphones.
A brief summary of how all this works:
The knock sensor gets unplugged. You connect it via alligator clips and the 12ft cable to the headphone volume control (to attenuate it, NOT to connect it directly to headphones), and then to either the pocket speaker/amplifier, or a laptop. If you will be using a laptop, you dont need the pocket speaker/amplifier. Anyways, from the laptop or the amplifier, you can connect it to headphones. With a laptop you can record the sensors output, which is nice because you can listen carefully to it later when you aren't driving, or share it with other people on here and see what they think about certain sounds.
A more detailed description:
The 12ft RCA/wire cable will connect the knock sensor to the inside of the car to whatever you will plug it into for recording or listening. Its got two wires sticking out of one end of it, and a male RCA plug on the other. Solder an alligator clip to each of the bare wires. Unplug the knock sensor from its harness and connect one alligator clip to the sensors little stud. Connect the other alligator clip to a nearby ground (I used the O2 sensor mounting bracket on the passenger side of the intake manifold). You should extend both the bare wires and heat shrink their solder joints so they dont short on anything.
Then run the cable inside the car (i just do it through the window). Plug the RCA to 1/8" mono adapter into the end of the cable. Then plug THAT into the headphone volume control.
The headphone volume control is required because I noticed that the output of the knock sensor was overloading my laptop when I was recording its output. (clipping) Even with the laptop's microphone setting at absolute minimum it would still clip at anything but idle. Basically the sensor is just TOO LOUD for a microphone or line-in input, so the volume control lets you attenuate its output.
Now if you have a laptop, you can connect the output of the headphone volume control to the laptops microphone in jack, or maybe the line in jack. Experiment and see what works for you. Just remember to adjust things so that when stuff gets LOUD (anything greater than idle really) the output of the knock sensor doesn't start overloading whatever is attached to it. (this is really only detectable by looking at the sound waveform with a laptop or an oscilloscope).
If you wont be using a laptop, plug the headphone amplifier output into the pocket speaker/amp and plug your headphones into the amp too using the stereo to mono adapter so you get sound in both ears.
Off you go!
Attached is a picture of the setup (minus the heapdhone volume control, which I got after I took the picture), and a link to a sound clip.
SOUND CLIP!
The sound clip is me idling at a light, then turning left and flooring it through 1st and 2nd. Peak boost was about 5 psi, as I have the wastegate connected directly to the intake manifold at the moment.
knock sensor 5 psi.wav
Anyone hear detonation in it? What does detonation sound like?
I recommend you download this file and play it on headphones.
I've read about homebrew ways to listen to your knock sensor, some on here, some on google.
Here is my setup, and a sound clip too!
All the parts for this were bought at radio shack:
Pocket Speaker/Amplifier (277-1008)
9V battery (230-0875)
Mini alligator clips (270-0374)
RCA to 1/8" mono adapter (274-0330)
12ft bare wires to RCA mono plug (420-2372)
1/8" mono to 1/8" stereo jack (274-0882)
Headphone volume control (420-2559)
And you will need some headphones.
A brief summary of how all this works:
The knock sensor gets unplugged. You connect it via alligator clips and the 12ft cable to the headphone volume control (to attenuate it, NOT to connect it directly to headphones), and then to either the pocket speaker/amplifier, or a laptop. If you will be using a laptop, you dont need the pocket speaker/amplifier. Anyways, from the laptop or the amplifier, you can connect it to headphones. With a laptop you can record the sensors output, which is nice because you can listen carefully to it later when you aren't driving, or share it with other people on here and see what they think about certain sounds.
A more detailed description:
The 12ft RCA/wire cable will connect the knock sensor to the inside of the car to whatever you will plug it into for recording or listening. Its got two wires sticking out of one end of it, and a male RCA plug on the other. Solder an alligator clip to each of the bare wires. Unplug the knock sensor from its harness and connect one alligator clip to the sensors little stud. Connect the other alligator clip to a nearby ground (I used the O2 sensor mounting bracket on the passenger side of the intake manifold). You should extend both the bare wires and heat shrink their solder joints so they dont short on anything.
Then run the cable inside the car (i just do it through the window). Plug the RCA to 1/8" mono adapter into the end of the cable. Then plug THAT into the headphone volume control.
The headphone volume control is required because I noticed that the output of the knock sensor was overloading my laptop when I was recording its output. (clipping) Even with the laptop's microphone setting at absolute minimum it would still clip at anything but idle. Basically the sensor is just TOO LOUD for a microphone or line-in input, so the volume control lets you attenuate its output.
Now if you have a laptop, you can connect the output of the headphone volume control to the laptops microphone in jack, or maybe the line in jack. Experiment and see what works for you. Just remember to adjust things so that when stuff gets LOUD (anything greater than idle really) the output of the knock sensor doesn't start overloading whatever is attached to it. (this is really only detectable by looking at the sound waveform with a laptop or an oscilloscope).
If you wont be using a laptop, plug the headphone amplifier output into the pocket speaker/amp and plug your headphones into the amp too using the stereo to mono adapter so you get sound in both ears.
Off you go!
Attached is a picture of the setup (minus the heapdhone volume control, which I got after I took the picture), and a link to a sound clip.
SOUND CLIP!
The sound clip is me idling at a light, then turning left and flooring it through 1st and 2nd. Peak boost was about 5 psi, as I have the wastegate connected directly to the intake manifold at the moment.
knock sensor 5 psi.wav
Anyone hear detonation in it? What does detonation sound like?
I recommend you download this file and play it on headphones.
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