Can anyone help fill me in on the motor that comes in the GEM cars?
Looking for specifics. Phase. Voltage. Typical RPM.
Can’t find much. Looking at comparable electric motors that weren’t necessarily designed for these cars, but with a little bit of motor mount manufacturing and some clever wiring - would be great replacements.
The stock electric motor in 2000+ GEMs is made by GE. It’s a separately excited motor - I.E. it has separate armature and field windings so has 4 terminals. The GE motor controller is matched with this motor and cannot run either an AC motor or a shunt or series-wound motor.
The designed RPM for this 5 HP motor is 4100 RPM. Reducing the field current further than stock settings allows it to run at higher RPM’s but at a cost. Raising the RPM beyond design limits can damage the motor over time and sometimes catastrophically. Running at higher average HP can raise temperatures to the point of failure.
So if you are looking for another motor, not originally designed for EV use, you’ll need to make sure it draws similar current (less than 350 amps peak) and has a separate field winding and connectors from the high-current armature. If you go with higher HP you will want to get one with fan-forced cooling to keep the temperatures under control and it will need the same shaft diameter and length with the same output gear attachment (splines, keyway or flat etc.) to match up with your GEM.
Check out Ride-4-Fun.com and their 7.5 and higher HP motors. They’ve been designed for higher performance on the GEM.
Thanks again Bob.
I bought the 7.5 hp motor from Ride 4 Fun and it is a hummer. I also have the 2002 5 hp motor I would like to sell if anyone needs one. The 7.5 is a great motor but your range will suffer if you have a heavy foot.
the more power taken by the motor will diminish the batteries… I’m finding because when I bought my motor that I had to try all the tests… speed… big hills… in 6 months I have pretty much killed my batteries… although they will still take me about 25 miles… I start out at 13.1 volts fully charged and the Battsix shows I run in the yellow or red after about 8-10 miles… the car has power and runs well… just a little undaunting
Bob