Many years ago I worked in the shop for an EZ-GO dealer. We found a company that would rewind the EZ-GO motors, giving them more power and higher speeds, so they claimed.
So, we sent a motor in for the magic treatment, then installed it in a cart.
We then held "drag races" in the parking lot between a stock cart and the modified one. Of course, we did not have NHRA accurate timing, but the modified cart DID seem to have more power, and definitely ran the course in less time than the stock unit, and, in fact, would run away from the stock rig!
IIRC, the modification was not exactly inexpensive, but it sure did work as advertised!
These were 36 volt units, probably late '90s.