Please tell me about ignition timing

[novocaine]

Thanks for all the replies guys, I think i understand now NoHachi.

I understand why i was told about the distributor mod. the dizzy advances the timing based on engine rotation speed using centrifugal weights, so modifying those accurately could have you leave your base timing as stock but still managing to have the max timing advanced by a certain number of degrees.

ie. if base timing is 10 and the timing after max advance is 40, setting the base timing to 16 degrees would give a max value of around 46+- and help high rev power, but with the drawback of losing bottom end power.
and to solve that the dizzy could be modified to have base timing of 10 but a max of 46...

is that right?