Torque motor options for 88 marathon

[Malachi]

Awesome. What are some good torquey motors for this axle that are pretty reliable? I could use a little more speed. But I mostly don't want to be underpowered when riding with a load or uphill. It is at around 13 mph at 48 volts on the 23 tires.

[cgtech]

Theres a vast selection of torque motors available for "series configuration" that will get you a little speed too (since the controller & stuff is already done). My builds are almost always more "street style", so, someone else may be better able to make a suggestion.

[Malachi]

Is there a certain brand most people prefer? There are just so many options I'm not sure which brande to get. It seems like d&d and plum quick are pretty reputable.

[handtools]

I'm real happy with the AMD 7114 "Beast" motor in my cart, plenty of torque and speed. I believe it would be a 7124 for an EZ GO.

[JohnnieB]

Admiral, FSIP, AMD and EMP are also good motors.

Your cart may be a good candidate for one of the two-speed motors made by EMP Motors that is set up to change modes on the fly.


Here is some info that may come in handy when talking to motor manufacturers.


The stock tire height for your cart is 18", so the torque is reduced by about 22% where rubber meets road, but to get the same amount of force applied from a different motor, the new motor has to have about 28% more torque.

I'm pretty sure the differential gear ratio in your cart is 12.44:1, so there will be about 166ft/lb of torque at the road/tread interface when the original motor is producing 10ft/lb of torque at its output shaft. To duplicate that amount of propulsion, the new motor will have to produce 12.8ft/lb at its shaft, or 28% more torque.

With 23" tires and 12.44:1 gears, the motor spins at 2,727RPM at 155MPH and 3,636RPPM at 20MPH. You said the cart slows to 13MPH on hills, which is 2,363RPM.

[Malachi]

I believe I am going to get the AMD 7124 beast. I am unsure of the torque this motor has. Would this motor surpass the 28% torque increase I need?

[orangeman6]

Johnnieb, isn’t the current 13 mph the op says he’s getting a little slow for his setup? Or is that what the cart is doing uphill?

OP, I’d check with chuck at EMP. In addition to the speed/torque switch option johnnieb mentioned, Chuck will get detailed information from you about your current setup and use. Then he’ll give you detailed information about your options. He puts quite a bit of effort into getting you what you want.

[Malachi]

What should I be getting with the stock motor at 48 volts? The motor is not in the best shape. The previous owner did not have the lugs tight on the motor and the studs were melted. I used a die to cut them to the next size smaller threads. A nut would just spin on it. I feared it may have overheated the motor. I also probably need to take the rear axle and go through it to make sure nothing is binding up and free spinning properly.

[JohnnieB]

Originally Posted by Malachi

What should I be getting with the stock motor at 48 volts? The motor is not in the best shape. The previous owner did not have the lugs tight on the motor and the studs were melted. I used a die to cut them to the next size smaller threads. A nut would just spin on it. I feared it may have overheated the motor. I also probably need to take the rear axle and go through it to make sure nothing is binding up and free spinning properly.

Mathematically, if the cart's stock speed was 12MPH adding 23" tires and upping the battery pack to 48V should yield a top speed of about 20MPH (Plus 28% from the tires and plus 33% from the voltage increase), but the cart will not reach that speed due to the 22% torque loss caused by the increase in tire height. Also, if the tires are the low pressure type (less than 10PSI max pressure), the top speed will be lower still, Low pressure tires take more torque to turn than high pressure tires.

I reviewed this thread and the cart's top speed with 23" tires, 48V battery pack and stock motor was never mentioned, just a desire for 15 to 20 MPH and that the cart slows to 13MPH on hills. The stock motor being in poor condition was also mentioned.

Series drives slow a lot more on hills than sepex drives or AC drives, and the % incline wasn't mentioned, so I'll guess about 25% slowing and speculate the top speed to be at about 16MPH.

Considering the cart is 32 years old, the 4 bearings on the front axles, the 2 bearings on the rear axles and the 6 bearings inside the differential may need replacing. And the motor oil in the differential need to be replaced with gear oil.

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Best bet is to tell some motor manufactures what you've got and what you want, so they can try to figure out what motor fits your needs.

[Malachi]

Thanks for all the help!!! I assume I can use the sticky on the page before this for my axle rebuild? Is it the same parts?