Random Knock Retard
Thread Starter
Burning Brakes
Joined: Apr 2023
Posts: 1,087
Likes: 392
From: Florida
2025 C6 of the Year Finalist - Unmodified
Random Knock Retard
I did a datalog tonight since its been awhile on my 2007 LS2 C6 A6. I noticed on the first pull it showed up to 11 degrees knock retard above 4k or so rpms. Second pull ZERO knock retard. Third pull only 2-3 degrees max kr… what gives? I can’t hear any knocking of any sort… What would cause it to pull so much timing one run then the next none? Are my knock sensors going bad? LTFT’s aren’t bad either so I’m not sure what would cause random kr, anyone? Thanks in advance… IAT temps were 99 degrees, i don’t have any spark correction in that IAT range compared to stock.
Race Director
Joined: Sep 2003
Posts: 16,836
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From: Database Error Indiana
Pretty sure the ecm learns when knock is present and pulls timing after. I was getting KR at the track. Second pass was always .2 seconds slower than the first. Octane fixed that.
Thread Starter
Burning Brakes
Joined: Apr 2023
Posts: 1,087
Likes: 392
From: Florida
2025 C6 of the Year Finalist - Unmodified
Yes sounds like your issue was iat heat soak etc pulling timing… i understand how the sensor works, I’m just not understanding how one pull I get 10-11 degrees knock retard then a couple minutes later still driving do another pull and get zero knock retard… What would cause this?
Thread Starter
Burning Brakes
Joined: Apr 2023
Posts: 1,087
Likes: 392
From: Florida
2025 C6 of the Year Finalist - Unmodified
