knock gauge kit for our trucks

[typhoon4ever]

will this kit work for our trucks. its says its for chevy/gmc trucks. its the last two kits at the bottom of the page http://www.casperselectronics.com/cgi-local/store/commerce.cgi?product=GMCARS

 

[Richme]

On 2002-02-14 02:32, typhoonrider wrote:
will this kit work for our trucks. its says its for chevy/gmc trucks. its the last two kits at the bottom of the page http://www.casperselectronics.com/cgi-local/store/commerce.cgi?product=GMCARS

I would like to know this also, anyone?

 

[smeagol]

I have posted about this subject several times.

http://syty.net/phpBB/viewtopic.php?topic=8399&forum=1

http://syty.net/phpBB/viewtopic.php?topic=8535&forum=1

Should cover all yer questions.. post if ya got more. Check out http://www.chitownsyty.com Tech section for the Knock retard LED setup, courtesy of Barry Tisdale & Opie ...

 

[Richme]

On 2002-02-14 10:26, Tom Servo wrote:
I have posted about this subject several times.

http://syty.net/phpBB/viewtopic.php?topic=8399&forum=1

http://syty.net/phpBB/viewtopic.php?topic=8535&forum=1

Should cover all yer questions.. post if ya got more. Check out http://www.chitownsyty.com Tech section for the Knock retard LED setup, courtesy of Barry Tisdale & Opie ...

Thanks, I forgot about that....oh, those vanishing gray cells.

 

[Lew]

Hey Brian:
Just what is Barry's LED indicating?
You stated knock retard but I thought that was only avaiable through the ALDL stream.
:smile:

 

[smeagol]

Good call Lew. It should be basically signaling the filtered knock sensor signal. So if it goes off, you have knock retard occuring (in theory). In testing it on Opie's truck, it seems to agree with the values on Datamaster. I'm not sure how intensity/flashing agrees with the amount/intensity of the knock signal though.

 

[Opie]

Here's how it works. The knock sensor is simply a microphone. This audio signal goes into a set of electronics that turns it into a pulse. When knock occurs, you get one pulse. If knock occurs again, you get another pulse. As soon as the ECU receives a pulse it retards the timing and holds that retard for some amount of time. If the ECU receives another pulse while it is already retarded, then it will retard the timing even further. After the amount of time has passed, the ECU will slowly release the retard.

So, with the LED, you are actually looking at the pulses. The LED will flash once for each pulse. If you the LED flashes multiple times (very fast flashes), then you have lots of knock. If the LED only flashes once, then it's a very small amount of knock.

Any questions?

 

[Tooky]

Yes, isn't this something everyone would want to use on their truck all of the time? And if so, why don't they? Your circuit looks so simple I think I will have to build one.