1991 high speed ezgo electric motor question.

[wpb3399]

I actually have a couple of questions:

1. What is the reason you cant use a high speed motor on the old resistor style ezgo with out upgrading to solid state?

Why couldnt a person take two heat coils and wire them together so you have double the heat coil to remove heat from the motor at lower speeds? Also upgrade to #1 wire for less resistance. Is there a reason this cant be done and if so why?

Also does anyone have any idea of what the heat coil wattage is rated for? I've called multiple places and have spoken to seasoned golf cart mechanics and no one can answer that question so any help would be appreciated with obtaining that info.

When I say heat coil I'm referring to the resistor coil. I know everyone has a different name for them!

[rockfordpi]

Originally Posted by wpb3399

I actually have a couple of questions:

1. What is the reason you cant use a high speed motor on the old resistor style ezgo with out upgrading to solid state?

Why couldnt a person take two heat coils and wire them together so you have double the heat coil to remove heat from the motor at lower speeds? Also upgrade to #1 wire for less resistance. Is there a reason this cant be done and if so why?

Also does anyone have any idea of what the heat coil wattage is rated for? I've called multiple places and have spoken to seasoned golf cart mechanics and no one can answer that question so any help would be appreciated with obtaining that info.

When I say heat coil I'm referring to the resistor coil. I know everyone has a different name for them!

I am not sure about the answer to your initial question. However,
based on the terms "heat coil" and "removing heat from motor" you used, I am not sure that you understand how a resistor cart works.

On any DC cart, the motor speed is determined and varied by changing the voltage to the DC motor. More volts, more speed and vice versa.

With an electronic controller cart, 36 or 48 volts are fed into the controller. The controller output to the motor varies (almost infinitely between zero and 36/48 volts) the voltage (based on pedal input) to control the speed.

On a resistor cart, the voltage is varied by changing the length of the resistor (amount of resistance) between the battery and the motor

One you first push down the pedal, voltage is traveling through all of the resistor coils which drops the voltage to motor way down.

When you push pedal down further, it cuts out one resistor, which means resistance is less and voltage (speed) is greater. Each time you push pedal further, one resistor is removed from the circuit increasing speed.

At WOT, all the resistors have been eliminated and full pack voltage is applied to the motor for max speed.

Basically a resistor cart has 5 set discrete (discreet?) speeds and you can't vary from those. Also, resistor cart is very inefficient because the it pulls same amps at any speed. At slow speed, voltage is reduced by the resistors which wastes a lot of energy as heat.

On an electronic cart, voltage is varied buy the controller and not wasted in the resistor bank.

Back to your first question, I think a high speed motor probably would technically work with a resistor cart, but not very well and would not be a good idea. Maybe the experts will chime in and explain this part a little better

[cgtech]

The increased load of the hotrod motor will burn out the resistor coils usually in less than a year .

[wpb3399]

Thanks for the reply. So you think the resistor coil will work but what's your thought about doubling up on the resistor coil do you think its necessary? I want to try this as its been my white whale for a long time just because the experts say it cant be done.

I have a Hyundai golf cart that I picked up for $50 and all it had was the motor and I converted it to the ezgo wiper board, heat coil and fnr switch and I will tell you this that cart is fast. I'm not sure it has a high speed motor or not but that thing will pretty much keep up with any of the newer carts in the neighborhood. The one thing I did notice is the heat coils do get extremely hot more so then they do on the old ezgo I have so I'm thinking it may have a high speed motor but not sure.

I love the simplicity and the availability and how cheap the old parts are and that they really never go bad minus a micro switch or solenoid.

[rockfordpi]

Originally Posted by wpb3399

Thanks for the reply. So you think the resistor coil will work but what's your thought about doubling up on the resistor coil do you think its necessary? I want to try this as its been my white whale for a long time just because the experts say it cant be done.

I have a Hyundai golf cart that I picked up for $50 and all it had was the motor and I converted it to the ezgo wiper board, heat coil and fnr switch and I will tell you this that cart is fast. I'm not sure it has a high speed motor or not but that thing will pretty much keep up with any of the newer carts in the neighborhood. The one thing I did notice is the heat coils do get extremely hot more so then they do on the old ezgo I have so I'm thinking it may have a high speed motor but not sure.

I love the simplicity and the availability and how cheap the old parts are and that they really never go bad minus a micro switch or solenoid.

Are you thinking about doubling the coils in series or parallel?

[wpb3399]

I would be doing them in parallel

[JohnnieB]

Apparently with pedal on floor, the cart is fast as more modern carts, so am I correct that the objective is wanting slower cart speeds 1/4, 1/2 and 3/4 pedal?

If so, you need to add more resistance in series with the motor to get a slower speed and placing resistors in parallel decreases the amount of resistance.

The thinnest of the resistor coils has the highest resistance and the lowest ability to withstand heat, however, the resistance on the coil is determined by the length of the wire it is made of as well as the thickness of that wire, so the resistance of the thicker coils will be increased if the length of the wire is shortened.

I've never seen or handled any of those coils, so I have no idea of how stiff or brittle the wire is, but it may be possible to chop off a loop or more of the coil and heat the end that is left with a torch and form it into a small ring like what was on the original end.

[wpb3399]

Okay so update here:

I put 6.1 gears in the rearend I swapped every wire to #1 wire, I upgraded to 8 volt batteries making the cart a 48 volt cart with the stock motor which after doing my research on the motor finding out its actually a multi voltage motor capable of 8000 rpms. THIS CART IS FAST! I actually cant imagine putting the high speed motor on it because of how scary fast it is but if the motor ever does burn out I will replace it with the high speed motor but for the mean time I think I would be scared to go any faster with it!

I'm going to clock my speed tomorrow and update on it!

Thanks everyone for all the helpful info!

[cgtech]

6:1 gears, horrid motor, stock resistor coils. This is a big recipe for constant repairs. Next, do you plan on installing 24" tall tires? Keep doing what your doing, its gonna be a money pit. I'm interested in what happens when you "parallel the resistors". If they are identical resistors, who knows, just might work. If they are resistors from different brand, one set of resistors (with its different values) is gonna end up "doing most of the work", while the other does very little. Even if they are the same model, I think slight production variances will leave one side doing most of the work.

[rockfordpi]

Originally Posted by cgtech

6:1 gears, horrid motor, stock resistor coils. This is a big recipe for constant repairs. Next, do you plan on installing 24" tall tires? Keep doing what your doing, its gonna be a money pit. I'm interested in what happens when you "parallel the resistors". If they are identical resistors, who knows, just might work. If they are resistors from different brand, one set of resistors (with its different values) is gonna end up "doing most of the work", while the other does very little. Even if they are the same model, I think slight production variances will leave one side doing most of the work.

I am with CGtech, interested to see what happens here. I have a hunch, LOL, but please keep us posted.