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Knock detect scan help

Posted: Sat Oct 15, 2016 12:55 pm
by Pair of SSEI
Ran a knock detector scan on my Torque Pro this morning. I have added a Gen V and SD headers, Have NOT done a tune yet, want to drop down to a 3.4 pulley first. I have the following numbers. Do not know what to make of it. Any help or suggestions are appreciated.


6 knock events from 63 samples
Knock event 1
RPM 5649.5 Speed 78
timing-13.5, correction -0.5
Knock event 2
RPM 5774 Speed 82
timing-14, correction -0.5
Knock event 3
RPM 3650.75 Speed 88
timing-15.5, correction -0.5
Knock event 4
RPM 4488.5 Speed 115
timing-15.5, correction -0.5
Knock event 5
RPM 4647.75 Speed 119
timing-15.5, correction -0.5
Knock event 6
RPM 5438.5 Speed 141
timing-15, correction -0.5

Re: Knock detect scan help

Posted: Sat Oct 15, 2016 3:47 pm
by Pair of SSEI
One other thing I need to mention. when first hitting WOT. I got a very fast "ding ding: warning from the car. Did not see any check engine lights and threw no codes. maybe traction control?

Re: Knock detect scan help

Posted: Sat Oct 15, 2016 4:54 pm
by garagerog
Just a question, am I reading that right? knock event 6 with a speed of 141 mph? Where were you testing at, Talladega? I hope you have tires with at least a V speed rating.

Re: Knock detect scan help

Posted: Sat Oct 15, 2016 5:19 pm
by RJolly87
It almost looks like it may be registering each "event" anytime there is a single instance of knock.

Most times, when a vehicle is being assessed, they are looking at the KR, or Knock Retard, which is the computer's response to sustained knock.

I really don't know how the two correlate, but I am thinking it may come back with no knock retard, especially if each "event" is a single "instance", especially with as hard as it was being pushed.

Re: Knock detect scan help

Posted: Sun Oct 16, 2016 10:04 am
by Pair of SSEI
I think the speed is kilometers. I was not that fast. Love to say my bonnie was doing 141. but I know better. she has seen 126 which is as fast as the computer will allow with a stock tune. I do not like the 15 degees of timing being pulled. Do not know if it is real KR or false KR. Still trying to wrap my head around this KR.

Re: Knock detect scan help

Posted: Sun Oct 16, 2016 10:42 am
by RJolly87
That's a whole different concern however, I don't even know that you are looking at KR. I get from the readings that the timing is at -15* from TDC, and the computer is then backing off .5* of timing (or .5* of KR) in response to each instance of knock. The collective response to multiple knocks is what stacks to make up the KR reading, but I don't know how long it counts a knock for, and how many it takes to start driving the KR number.

If it works the way I am interpreting the data, then this would likely show as 0* KR.

Re: Knock detect scan help

Posted: Mon Oct 17, 2016 1:44 pm
by 2000Silverbullet
I don't think installing a 3.4" pulley with your mods will hurt.

Re: Knock detect scan help

Posted: Tue Oct 18, 2016 6:34 pm
by Pair of SSEI
Alright, now I am ready for the 3.4 pulley.
Thanks all