iginiton timing questions

How do you know what RPM your timing should be all in at? Is that a standard RPM or is that effected rpm range of the motor or anything? When we are talking about all in that is mechanical only not with any vac? Also for example lets say I am all in at 32 at 2600rpm for a total. So if it rev up to 4000rpm 32 degrees it should still read with out the vac plugged?