Knock... I expect some
12-26-2014, 11:28 PM
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Knock... I expect some I’m hoping a few of you that have much more LS1 experience could give some advice. I have a basically stock 2001 C5 LS1 (K&N, trunions, ls6 pcv) with some minor tune massaging. My concern is knock.
I have false knock, so I added 50% e85 and dialed back the Global Gain. Love this tune and no worries, BUT I want to run pump when traveling to distant road tracks.
I’m in AZ and the 91oct here sucks *****… at least with my BMW turbo experience. So I’m expecting at least some knock even with good tune and cold temps.
My gain in the upper MAP is 1.75 compared with 1 stock. At 1.5 I get false knock. So I’m a little concerned that I have basically disabled my knock sensors.
Attached is my timing histogram with <50deg ambient and 91oct today. Common to never see knock with a good tune?
The scan is 186kb, so a lot of driving and at least 5-6 WOTs.
And I’ve disabled burst knock, so I’d think I should see some KR during transitions.
I’m guessing the knock threshold is basically = (Gain) x (Knock sensor level)
I don’t see how you’d ever gen knock at <50 MAP… the gain is so high.
Any thoughts would be great!
I have false knock, so I added 50% e85 and dialed back the Global Gain. Love this tune and no worries, BUT I want to run pump when traveling to distant road tracks.
I’m in AZ and the 91oct here sucks *****… at least with my BMW turbo experience. So I’m expecting at least some knock even with good tune and cold temps.
My gain in the upper MAP is 1.75 compared with 1 stock. At 1.5 I get false knock. So I’m a little concerned that I have basically disabled my knock sensors.
Attached is my timing histogram with <50deg ambient and 91oct today. Common to never see knock with a good tune?
The scan is 186kb, so a lot of driving and at least 5-6 WOTs.
And I’ve disabled burst knock, so I’d think I should see some KR during transitions.
I’m guessing the knock threshold is basically = (Gain) x (Knock sensor level)
I don’t see how you’d ever gen knock at <50 MAP… the gain is so high.
Any thoughts would be great!
01-23-2015, 12:47 PM
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Just wanted to bump this thread.
An interesting observation in some of my logs...
Older log would have KR, but it would reset to 0 during a shift or when I let off.
Newer logs KR is X but during shift or when I let off it ALWAYS hits 1.9 then gradually transitions to 0
What could cause the difference? I'm not seeing anything in the tune that would alter this.
Logs below showing difference.
An interesting observation in some of my logs...
Older log would have KR, but it would reset to 0 during a shift or when I let off.
Newer logs KR is X but during shift or when I let off it ALWAYS hits 1.9 then gradually transitions to 0
What could cause the difference? I'm not seeing anything in the tune that would alter this.
Logs below showing difference.