David Vizard in his book "How to Build Horsepower" give a general, non-mathematical, description of the ignition process vs rpm.

So I don't violate copyright, I will paraphrase.
He writes that apart from the physical characteristics of the combustion chamber, RPM, manifold vacuum, fuel type, and other factors; mixture motion has a big effect on the combustion process.
Best power output occurs when the cylinder pressure reaches its highest level at about 15 degrees after TDC under all conditions. This is governed by the geometry and mechanics of the engine.
When the engine is turning below ~2000 RPM, the combustion rate of the fuel/air mixture is about the same. So, as the engine speeds up, the piston is moving faster, but the combustion front isn't, so it will take about he same amount of time for the combustion to finish. This means that the ignition timing needs to advance as the engine is going faster to have the same time for combustion before the piston reaches 15 ATC.

Between about 2000 and 3000 RPM, the mixture is moving fast enough that it starts to increase the rate of the fuel burning. The faster the mixing, the faster the fuel burns. After about 3000, or so, the rate at of mixing is increasing the rate of fuel burning very closely to directly proportionally to the increase in RPM. Therefore, no change in timing is needed as RPM increases.

This is all generally true for a 4 stroke internal combustion, normally aspirated engine. But each engine and setup will vary the details.

I highly recommend any and all books by David Vizard. He has decades of extensive experience as a race engine engineer and writes in a very clear way and backs his statements up with hard data and clear plots.
The "How to build Horsepower" book is particularly good.

Robert

The key to finding the best ignition advance for any motor is to first verify the mark on the balancer and the timing tab to insure TDC or zero is at TDC, then verify the advance marks on the tab and or on the balancer with a degree wheel referenced to TDC on the pistons.
The next important thing is to make sure your timing light is accurate also and then at the race track or on a engine dyno find the best total ignition timing for that day with that fuel and weather conditions.
Once your in the ball park on the best known correct, accurate, ignition timing to run the best ET and MPH or make the most HP on the dyno that day is to make several runs or pulls with less than the best known total timing for that motor and then sneak up by adding 1 to 2 degrees advance at a time until it starts to slow down on the 1/4 MPH or make less power on the dyno. If it runs the same at 34,35 and 36 degrees BTDC then you know what your motor likes.
To answer your question about the motor liking more advance they will talk to you if you listen and test, they are like women, they like what they like that day, more ain't better, same on less also
I have raced Mopar V* since the early 1960s, all the 318,340 and 360 NHRA stocker motors I've built, dyno tested and raced at the track like 30 to 32 degrees total timing for the best E T and MPH.
A friend of mine race several different 340 and 360 cars in NHRA stock for many years that he set class records that he said they like 38 to 42 degrees total timing, he thought and believe they like that until he retarded one back to 34 trying to slow his car down in qualifying so he wouldn't get HP added onto his class. The car went faster and he broke out first round
He called me on his way home about it speeding up with less timing and later ended up finding out at a different track that his car like form 30 to 33 degrees BTDC maximum total at WOT and above 4500 RPM, not from 38 to 42 like he believed before because another racer told him that on a race car he had bought from that guy
Your trying to get the maximum push on the top of the piston as it starts down on the power stroke, any thing less makes less power and any more advance will lead to pinging or detonation slowing the car down and making less power also.

Ignition timing is all about trying to make the most pressure, at the latest crank angle possible. Create the pressure too soon, and it simply tries to push the crank out the bottom of the block (no crank angle = no rotation). If you wait too long, the piston moves down the hole too fast, lowering the compression/pressure.

A motor at WOT will require the least amount of ignition timing at peak torque. This is because the engine is breathing best (highest Volumetric Efficiency %) at peak torque. With the cylinder packed with Air/Fuel at this RPM, it needs less timing. Think of it that the air/fuel molecules are packed closer together, and react quicker.

At any RPM before or after peak torque, more ignition timing is needed because there is less air/fuel packed into the cylinder (lower VE%). With the air/fuel molecules spread further apart, it takes longer to burn from one to another to the next. So since the burn time is slower, you need to ignite it earlier to achieve the same cylinder pressure.

Let say hypothetically that a motor makes peak torque at 6000 RPM. It's likely (somewhat) that it will want the same timing at 5,000rpm (1,000 RPM lower than peak torque), as it does at 7,000rpm (1,000 RPM above peak torque). Although you might think that because the piston has less time near TDC at 7,000 RPM vs 5,000 RPM, and might want more ignition timing. The reason it doesn't is because the higher engine speed actually rapidly mixes the air/fuel much better, which speeds up the burn process.

Just so you don't think I'm BSing you... lol "As engine speed increases, the intensity of turbulence, swirl, squish, and tumble all increase, resulting in a faster flame speed." (Engineering Fundamentals of the Internal Combustion Engine, p280)

Basically the flame speed increases directly with RPM, which offsets the need to start the burn sooner.

Does anyone know what the timing curve looks like for a 500-inch Pro Stock engine ?