ManBearPig
Well-Known Member
- Thread starter
- #1
I have read that positive knock while "cruising" is deemed acceptable. Maybe not desirable but acceptable. My question is….what defines this? Under what circumstances and how much knock is acceptable?
I often see positive knock very briefly at throttle tip-in. Mostly when accelerating normally and rolling back into the throttle after shifting gears. Sometimes I'll see the same thing when on and off the throttle just cruising at freeway speeds. When I see any of this it's usually under 1* and goes away very quickly before turning into negative numbers (adding timing). Every now and then (usually when accelerating more aggressively, but still not WOT) I'll see a larger knock value after shifting gears that stays 2-3 seconds before going away. This is usually around 2* or less but I recall seeing 4* on one occasion. I always see the car add timing at WOT and usually see 27*-29* SAFTOT, which is right around where it should be.
None of this knock is very consistent as a good portion of the time, I'll see spark being added (negative numbers) immediately after each gear change and throughout all acceleration. I really don’t think I'm getting false knock as I am running stock exhaust and there is ample clearance everywhere under the car. However I tried a few gallons mixed with Torco and didn’t notice any difference so it would seem to not be octane related either. I see this on the stock tune and my Lund tune so I'm not blaming the tune, just wondering if this is "normal" or if there is something mechanical going on with my car.
I often see positive knock very briefly at throttle tip-in. Mostly when accelerating normally and rolling back into the throttle after shifting gears. Sometimes I'll see the same thing when on and off the throttle just cruising at freeway speeds. When I see any of this it's usually under 1* and goes away very quickly before turning into negative numbers (adding timing). Every now and then (usually when accelerating more aggressively, but still not WOT) I'll see a larger knock value after shifting gears that stays 2-3 seconds before going away. This is usually around 2* or less but I recall seeing 4* on one occasion. I always see the car add timing at WOT and usually see 27*-29* SAFTOT, which is right around where it should be.
None of this knock is very consistent as a good portion of the time, I'll see spark being added (negative numbers) immediately after each gear change and throughout all acceleration. I really don’t think I'm getting false knock as I am running stock exhaust and there is ample clearance everywhere under the car. However I tried a few gallons mixed with Torco and didn’t notice any difference so it would seem to not be octane related either. I see this on the stock tune and my Lund tune so I'm not blaming the tune, just wondering if this is "normal" or if there is something mechanical going on with my car.
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