Your DD motor is severely amp-starved. That is a 1000W motor, which will likely handle easily double that for fairly short periods, and you are only giving it a bit over 700W.
It is important to have some sort of INTERNAL temperature monitoring to avoid melting the motor, but you can safely feed that thing double the current amp load, again, for fairly short time periods. A few minutes, maybe even 10-20, but that leads back to the necessary temperature monitoring, and again, INTERNAL temp sensor.
That leads to oil or ATF fill, or Statorade, and/or external heat sinks.
It is important to have some sort of INTERNAL temperature monitoring to avoid melting the motor, but you can safely feed that thing double the current amp load, again, for fairly short time periods. A few minutes, maybe even 10-20, but that leads back to the necessary temperature monitoring, and again, INTERNAL temp sensor.
That leads to oil or ATF fill, or Statorade, and/or external heat sinks.