Why does my car knock so much in the 2-4k range?!
Why does my car knock so much in the 2-4k range?! It's starting to really **** me off. I have pulled my timing tables well below the stock tables and that isn't right in a cammed car. I've pulled a significant amount and it goes away, but why do they have to be SO DAMN LOW!? What's the deal? Anybody have any insight?!
Last edited by LSWHO; Sep 21, 2011 at 02:06 PM.
its probably insanely lean in that spot........a lean condition WILL cause detonation........and excess cylinder heat......fix it dont drive it.......
My wideband was reading richer there than anywhere else in the power band. I tuned it richer there to try to cool the charge and reduce knock. It helped some, but it's still there.... and I JUST fried my PCM so I won't be driving it much.
I shouldn't be doing it there. well at 2k at least. Almost every LT1 i have tuned i have and to keep timing conservative around the 4k spot because that is where the most VE typically is.
By richer there than than anywhere... what are we talking A/F wise. also timing wise.
By richer there than than anywhere... what are we talking A/F wise. also timing wise.
I shouldn't be doing it there. well at 2k at least. Almost every LT1 i have tuned i have and to keep timing conservative around the 4k spot because that is where the most VE typically is.
By richer there than than anywhere... what are we talking A/F wise. also timing wise.
By richer there than than anywhere... what are we talking A/F wise. also timing wise.
A/F has always been half a point richer in this area than the rest of the rpm band. In the 12.7 range. And if it's not reading accurately then I should see MORE knock up top from being even leaner, but it isn't the case.
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From: CT/NJ
Telling him to turn down the KR sensitivity at this point would be bad, unless you have further knowlege of his setup and the actual conditions of the knock occuences (2k in 6th @ WOT?).
Stalled auto + 6th at WOT? ??
Knowing he has a stalled auto, there should be very little load on the engine at that point.. Get the fueling right and it will help, then time it conservative there and if it doesn't go away its probably false. It will be fine to tune it out.
Knowing he has a stalled auto, there should be very little load on the engine at that point.. Get the fueling right and it will help, then time it conservative there and if it doesn't go away its probably false. It will be fine to tune it out.
Its a misconception that rich will cure knock and its simply not true. If you're loading up the cylinder combustion will never happen predictably or when you want so to speak. I have tuned cars that wouldn't take anyore timing than stock but were super rich. Fix the fueling, and then the timing. We were able to increser it significantly with no knock, after fueling was close.
Another thought is you may be getting some reversion from the cam at that point.
If its false knock it could be a harmonic resonance in the valve train as well.
Another thought is you may be getting some reversion from the cam at that point.
If its false knock it could be a harmonic resonance in the valve train as well.
BTW overly rich to "cool the charge" is a myth... Don't do that
