My Demon 5.7 hemi carb swap
The decrease in timing from 6 PSIa to 11 PSIa is understandable -
I can see that as Intake pressure increases - the MAP advance is reduced because the "mechanical" advance is increasing - just as Vac advance backs off as mechanical advance increases under WOT.
Here's what I see happening from 11 PSIa onwards - the MAP chart is actually pulling timing OUT of the total!
So even if the RPM chart is programmed for 28 degrees at WOT at 4000 - IF the intake pressure goes above 11 PSIa at WOT...........it's start taking timing away from that 28 degrees.
Thats the way it seems to me anyhow? :-k
The decrease in timing from 6 PSIa to 11 PSIa is understandable -
I can see that as Intake pressure increases - the MAP advance is reduced because the "mechanical" advance is increasing - just as Vac advance backs off as mechanical advance increases under WOT.
Here's what I see happening from 11 PSIa onwards - the MAP chart is actually pulling timing OUT of the total!
So even if the RPM chart is programmed for 28 degrees at WOT at 4000 - IF the intake pressure goes above 11 PSIa at WOT...........it's start taking timing away from that 28 degrees.
Thats the way it seems to me anyhow? :-k