[Kenth]

Atmospheric pressure, about 14.7 psi, will regardless of vehicle speed fill the vacuum in intake below the throttle plates in various grade depending on throttle blade position thus regulate power output of the engine.

To gain Ram Air effect, more than 14.7 psi, how fast do you need to drive?

I´ve came to the conclusion the RamAir system is to induce cold denser air into the carb/intake to burn more fuel, instead of overcoming the atmospheric pressure.

But, i could be wrong.