Qouting PStechPaul here: "
I don't have experience with large motors as used in EVs used for passenger cars and trucks, but I have done extensive reading and I have these books:
and one or two others.
After learning about the pros and cons of various motor types, especially for vehicle application, I decided that the three phase induction motor was the best overall, for reasons of cost, ruggedness, low maintenance, and ease of control. They can be tweaked for maximum efficiency at low torque, and can operate at up to 3 or 4 times rated torque before stalling. They can be used for regeneration and dynamic braking, and can be overclocked to obtain perhaps 2-4 times the HP at higher speeds and voltages.
I know that BLDCs are extremely popular, but they tend to be more expensive, and relatively fragile, with catastrophic failure modes. The advantages are small size, high efficiency, and high peak power and torque.
For raw power and torque, the series wound motor can be pushed as high as 10x rating, but only for short durations and at the expense of fast wear and damage to brushes and commutators. They are also difficult to control and don't make good generators.
So, yes, there are ways to "boost" the output from any motor. The limitations are as you have noted, based on temperature, conductivity of windings, voltage limitations of insulation, demagnetization, and mechanical stress and failure at high RPMs and torques beyond the original design specifications. "
Yhis and other reasons are why I want to go with 3-phase, the bigger the better, I am really liking the 4o Horse models, that I saw at the shop that may or may not be good "spin freely, no scorch marks" I want to know more about "overclocking these puppies, or is there a way to incerase the efficiency? I wish to seek this method, even though it is suggested to do a dc conversion first for ease, and price. I have many of the components necessary, I just need batteries, and controllers/charger. I want to do this as efficient as possible, with emphasis on efficiency. I also want to do it right.