Not exactly, your engine will create vacuum at idle, cruising, and during part throttle acceleration. During these times the engine can benefit, and tolerate, more timing. So the vacuum canister uses this vacuum to increase the timing of your ignition, usually around 10 deg. or so. When you run at WOT (Wide Open Throttle), the vacuum drops to 0 and your timing returns to it's initial setting, usually around 8-12 degrees, thus preventing detonation. Then the mechanical advance comes into play, but that's a totally different mechanism. A vacuum advance improves throttle response and driveablility, but is totally out of the equation during full throttle runs. If you were running your engine without the vacuum advance connected you'd have terrible part throttle response, and surges while cruising. So to sum it up; the more vacuum (less load) your engine creates the more advance the vacuum canister imparts, the less vacuum (more load) the less advance.wow,
You guys are great!:bigthumbsup
So as the vacuum goes closer to 0", the engine would, in essence, be out of time and vacuum advance corrects this imbalance?