Each engine will be different, and consequently, each curve will be different. We're not done yet. Factory passenger car distributors and aftermarket distributors used on street cars usually incorporate both systems. Both systems function independently of one another. Centrifugal advance is based upon a set of governor weights and springs, which in turn are controlled by engine rpm.
Centrifugal force moves the weights outward against the tension of the springs.
This causes the distributor cam, and consequently the spark timing, to advance. Vacuum advance arrangements are more complex. All vacuum advance units operate on a system where the diaphragm reacts to the difference between atmospheric pressure and induction pressure. The way they operate is different. Early, pre-emission vacuum advance units typically were linked to a manifold vacuum source.