Brush Reinsertion trick. Many people wonder why free car alternators off the shelf are not used for wind turbine electrical generation. The Windings are very thick wire limiting the amount of wire turns per coil around the stator. Car engines have a lot of torque and idle RPM. The pulley on car alternators are usually much smaller that the engine’s crankshaft pulley. This allows for much higher RPM in the alternator. Car alternators do not have permanent magnets in them. They use an electromagnet to produce the flux in the coils. They need to be energized or excited. Car alternators have a high level of cogging.