My Demon 5.7 hemi carb swap

OK - fwiw and for those that want to know - the horizontal axis is manifold pressure measured in PSIa (Pounds per Square Inch Absolute sea level)

As Manifold pressure increases, the MAP sensor pulls the timing that was added initially for lower intake pressures found at cruise (Like a Vac advance but using Intake pressure)

As Swifter commented...I do wonder what happens when Manifold pressure reaches 11 PSIa ?????.......as the MAP chart shows its taking timing out after pressure reaches this level.