ArKay99
August 2nd, 2008, 01:56 AM
B5916 Base Spark Closed Throttle Threshold
B5917 Base Spark Vehicle Speed
I've been looking at timing during very low load in regards to surging/bucking issues lately and have been seeing some very interseting results. These results have brought me to look at these 2 cells.
Mine are set to:
B5916 = 1.191%
B5917 = 256mph
The descriptions are:
B5916: If the throttle is below this value and vehicle speed is below threshold, then it is considered closed and the base spark tables will be used
B5917: If the vehicle speed is below this value and the throttle is below threshold, then the base spark tables will be used.
I am using a drive by wire setup and my throttle position never goes below ~8%. However I do know that my pcm transitions from the high octane to base spark table. However, it seems that it oscillates between the 2 at the very low load. My throttle opening is somewhere around 10% when this occurs.
My question for B5916 is: It seems that in the case of drive by wire that this value is % of change or something else is controlling the transition. Is this the case?
My question for B5619 is: If this is set at maximum it would seem that the base spark table should be entered as soon as the pedal reaches the idle position. Why would I want to be using idle spark values with rolling air and fuel values?
B5917 Base Spark Vehicle Speed
I've been looking at timing during very low load in regards to surging/bucking issues lately and have been seeing some very interseting results. These results have brought me to look at these 2 cells.
Mine are set to:
B5916 = 1.191%
B5917 = 256mph
The descriptions are:
B5916: If the throttle is below this value and vehicle speed is below threshold, then it is considered closed and the base spark tables will be used
B5917: If the vehicle speed is below this value and the throttle is below threshold, then the base spark tables will be used.
I am using a drive by wire setup and my throttle position never goes below ~8%. However I do know that my pcm transitions from the high octane to base spark table. However, it seems that it oscillates between the 2 at the very low load. My throttle opening is somewhere around 10% when this occurs.
My question for B5916 is: It seems that in the case of drive by wire that this value is % of change or something else is controlling the transition. Is this the case?
My question for B5619 is: If this is set at maximum it would seem that the base spark table should be entered as soon as the pedal reaches the idle position. Why would I want to be using idle spark values with rolling air and fuel values?