Ok with more and more discussions about tuning and more and more about the effects of poor tuning I thought I'd start a thread on Knock or detonation and how to identify it, what it sounds like on our trucks and what tools have been tested for detection.
First we have two Bosch style knock sensors mounted under the intake manifold one on each head of the motor. The harness clip at the front right (Drivers Side) above the Cam housing is a connector for both sensors.
The detonation zone for this truck is 2800-4500RPM. This is a very crucial area as peak torque is made as well as 100% loads on the motor Not to mention that the motor stock runs lean in first gear under the loads as seen in the .PDF file below. I have marked in yellow the area where the timing was retarded.
I built a knock audio cable that I use to listen for knock via the AUX jack on the factory radio. I also have a PIE amp connected to the AUX line that helps to amplify the audio I still have to turn the volume to 30 to hear well. The cable uses parts from radio shack and can be made under $12. I’ll post a parts list so you all can make your own. I’ll also post an audio file and install pics from the truck later. Here's the audio listen for it at 5 and 10sec.
http://s93.photobucket.com/albums/l8...KnockMovie.flv
yeah listen at the 5-6 sec and 9-10sec parts of the video that is severe knock. And yes it sounds a lot like static....I want at all times a static FREE truck. I had to convert the .wav file to a movie so that I could share it. In doing so some of the crisp audio is lost.
There are much better amplified knock detection devices but they are for the tuners and can cost $700.
http://www.theknockbox.com.au/
More sound files:
http://www.theknockbox.com.au/index....ew&id=29&Itemi d=59
Another member has bought and tested another device that uses lights. He has found it to work well. Here’s a link to what I’m referring:
http://tunertools.com/articles/KnockLite.asp
There are other methods of doing this as well and each of these has their purpose. For instance NA guys would be fine with the audio cable the S/C guys due to added whining might prefer the lights.
Hope this helps you out and keeps your motor running for 100K. I would recommend a tool like this for all that are modding beyond CAI and exhaust.