[cdewlen]

Suppose your car flows 300 CFM and the tank that you describe has an additional 10 cubic feet of air inside of it (at 100 PSI). If (and here is the problem), if you could dump all of that air at pressure into the intake at one time then you could raise the pressure inside of the engine. The problem that you will run into is that you have 10 cubic feet of air that is flowing through a hose 1/4 or 1/2 inch from the tank to the intake. There is no way to get all of the air into the intake at once to increase the pressure to anything noticably above atmospheric levels. It is like trying to blow a straw into a 5 gallon bucket and expecting to increse the pressure in the bucket. Could you possibly make a difference? Yes, but it would be so small that it would not be measurable. Combine the fact that as your are trying to increase pressure in the bucket, new air is flowing in at atmospheric levels while your air is flowing out of the bucket and you are fighting a battle that can't be won. You also would run into a problem of the pressure in the tank dropping very fast as air came out. Your peak air would be at 100 PSI, but as air comes out of the tank your pressure would drop so your flow rates would drop as well.

Sorry this is kind of jumping around, but your question just got me to thinking.