How do you figure that?? Have you run both the Ramtec and Dynamax rotors side by side and measured everything? I have... The Ramtec is faster in the air, its more pitchy and when it used to run with the OS91 it revved a little lower than the Dynamax but was faster in the air, ask anyone who has run the two. With electric its important to pick the correct motor to suit the fan and the ramtec with the correct motor is a great performer.