Timing philosophy Marelli.

[michass]

Hi,


in my Marelli 8GMK Giulietta i have found something wierd to me. I have Base spark advance map and RPM/Intake efficiency max torque spark advance.

As i understand Base spark is start point map for timing. max torque map is ideal best timing for efficiency, in assumption if there is no knock and advance in base should be lower at some points to prevent of knock, but if there is no knock, Base timing should be equal to max efficiency. But there are some points, where base is bigger than max efficiency. As I understand if spark is too early, then efficiency drops. Maybe this is for emissions? Is a good thing to retard Base to Max effic, where it is possible?
949231

Thanks in advance

[UNOFEAR]

I never study which spark mode is using and when but from logs in MM10JA the ecu follow the timing from map RPM/Intake Efficiency maximum spark advance correction

[michass]

Thank you.
But at WOT there is more like base. Maybe during cruising, when knock ins not limiting factor, ECU want to be as close as efficiency map.

[UNOFEAR]

The base spark advance that you posted is only used in homogeneous mode and not in WOT condition,try the map that i mention you.