I don't think so.. what is under test is a V/Hz drive, the voltage and frequency increase up to nameplate frequency , and then voltage remains constant (at a maximum) so bearing in mind that the torque and hp readings are taken at the point where current reaches nameplate current, I can't see how hp could ever be higher at 60hz than it is at 50hz.
Rated frequency is just a line in the sand, it can be anything within reason, it's just the point at which maximum voltage is applied to the motor. You could reprogram the VFD to make the base frequency 100Hz if desired. The logic doesn't change. You won't get more power above base frequency. You just get less power everywhere else :)
That said, I'm surprised the 60hz data is so low, I would have expected about the same hp as 50hz.
Here's the standard hp vs torque graph.
Attachment 318501
Ray