Manifold Vacuum Experiment

Just to beat on this topic a bit further.

Looking at the physics/mechanics of a vacuum canister.

*The canister in theory works in the opposite effect of a compressor where the engine creates the vacuum within an enclosed area.

*The larger the canister the more volume to draw from/to although the Hg's will never exceed what the source is capable of producing.

*Multiple smaller canisters daisy chained would have the similar effect.

*The purpose of the canister is to prolong the desired vacuum effect for the desired duration of time or lapse.

Ex..Vacuum canisters work on boosted brake systems because they provide resource and reserved negative pressure to keep the booster diaphragm engaged for the requested duration when engine vacuum diminishes. Acceleration then suddenly slamming the brakes.

So, my question is: How do you best determine what advance curve you need based on vacuum volume? Trial and error?

Please forgive me if none of this makes any sense, different part of the brain waking up.