Sorry Sprocket,
i don`t understand these values.
For what is it good for?
When any Cylinder the Spark comes later or earlier??? In time : xxx uS
It is an indication of combustion efficiency.
I'm not sure how it is calculated, but it is derived from the acceleration of the crankshaft during each individual cylinder combustion stroke.
Therefore, if you have dramatic differences in values between cylinders, combustion is inconsistent.
As can be seen in the gragh above individual power5 is clearly not performing, and was found to be miss firing. Basically, no combustion with no crank acceleration as a direct result (most likely decelleration). Individual power3 shows poor performance compared with the other good cylinders. This could be anything such as poor combustion, lean mixture, poor cylinder sealing, poor spark, basically anything that would atribute to poor combustion, and thus lower crankshaft acceleration.
worth noting at this point, I am not sure how these individual power values are related to the ignition chanels, whether directly linked to the ignition output configuration (Individual power0 is ignition chanel 0 ?? ) or refference tooth table (individual power0 is first event in refference table ?? )
At the moment it doesn't matter what the actual value means, only if there is a difference, indicating an issue on the cylinder.
Knock I suppose could be detected, but then you would need to be able to understand what you are looking at. At a recent seminar at Swansee Metropolatin University, we played around with an engine on the dyno with in cylinder pressure sensing. Short of pushing the engine into detonation, the ignition was over advanced to demonstrate what happens. The cylinder pressures became erratic and un predictable, ether happening earlier or later, with a noticable loss of power. I can only assume this would translate into varying crankshaft acceleration per cylinder ( the graphs would be more peaky, than a straight line). Taking the extra advance back out made combustion more stable and repeatable with peak cylinder pressures around that magic 14 or 15 degrees ATDC.
Bottom line. It is a comparison of cylinder performance, nothing more. the same could be shown with EGT sensors in each exhaust port, or in cylinder pressure sensors in each cylinder.
