Lets talk about Vacuum Advance.

[jorgensensc]

When you hook the Vacuum advance up to the carb, and vacuum is created, does that advance the timing and if so help me understand the concept. Full vacuum is at idle right? So at idle does it advance the timing, then reduce timing as you drive/ accelerate? This doesn't make sense to me (not much does I think). If you over advance your dizzy when you are setting timing, It will have a hard time cranking, but it tends to run better at speed and has quicker response (Unless you way over advance it and then you get the popping in the carb, etc). So why would you want the timing advanced at idle and reduced at speed? Or am I completely Backward in my thinking. Also on the carb I have always been told that the dizzy advance is supposed to be plugged in to the carb port that is NOT Manifold vacuum (usually on Edelbrocks the drivers-side), however I have always been told to use the opposite port (Passenger-side), the constant manifold port for better performance. Can someone please shed some light on this?
Shawn