Knock, AFR. spark advance question.
11-10-2007, 12:57 AM
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Car: 1992 Trans/am convertible
Engine: 305 TPI
Transmission: 700r4
Axle/Gears: 2.73 drum WS6
Knock, AFR. spark advance question.
Hi, I just took my first logging run today.
I was looking over the stuff I recorded and I am getting some knock counts and up to 9.32 degrees retard on timing when knocks occur.
When the knocks occur my target AFR drops to 11.7 with spark advance of 36.56 degrees (relative to TDC). The oxygen sensor is reading 888.42mV.
I get knocks at 2475 RPM. Usually when i get on the car. Now, after countless reading on this board (last 6 or so hours) I know that 11.7 AFR is a bit low and 12.8 is more ideal for enrichment mode. I am not sure if this indicates a lean condition and detonation or not.
Note that at this time I am giving it gas (but only going 40mph) 9.32 retard is the highest it got, which was at 35.16 rel to TDC. 2600rpm
At 3500RPM and higher I get no knock retard and my total advance is 32.34 degrees.
Sorry for all the numbers. I am just trying to make sense out of it.
In a nut shell at 2500-3000 RPM's I get knock which can get up to 9.32 degrees retarded. The targeted AFRs drop to 11.79 before the knock occurs.
What can you make out of this?
I was looking over the stuff I recorded and I am getting some knock counts and up to 9.32 degrees retard on timing when knocks occur.
When the knocks occur my target AFR drops to 11.7 with spark advance of 36.56 degrees (relative to TDC). The oxygen sensor is reading 888.42mV.
I get knocks at 2475 RPM. Usually when i get on the car. Now, after countless reading on this board (last 6 or so hours) I know that 11.7 AFR is a bit low and 12.8 is more ideal for enrichment mode. I am not sure if this indicates a lean condition and detonation or not.
Note that at this time I am giving it gas (but only going 40mph) 9.32 retard is the highest it got, which was at 35.16 rel to TDC. 2600rpm
At 3500RPM and higher I get no knock retard and my total advance is 32.34 degrees.
Sorry for all the numbers. I am just trying to make sense out of it.
In a nut shell at 2500-3000 RPM's I get knock which can get up to 9.32 degrees retarded. The targeted AFRs drop to 11.79 before the knock occurs.
What can you make out of this?
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