VO Less vacuum in the intake manifold 'cause the throttle is open more. Lee .. ----- Original Message ----- From: "van Oss" <vanOss@centurytel.net> > So here is the main thing I > don't grasp: If the RPM is the same, then valves are opening and closing at > the same rates. How does more air pass through if the valvetrain is at the > same RPM?