First Steps for MORE POWER

[ndhill1976]

I have a 2004 EZ GO TXT 36v Regin golf cart. I bought it a couple of years ago, and it already had the 6" lift kit, 22" tires, and a back seat. My batteries are about to crap out and it's time to buy new.
Everything still works okay, but it really struggles with hills. I understand that it's the big tires with stock controller/motor that is the source of my pain.

I want more torque first and foremost, but extra speed would be a nice addition if possible.
I have been studying this for a while and I keep going in different directions with so many options available.

Option 1. Buy new controller/solenoid and keep the 36v setup and replace the motor in the future.

Option 2. Make the switch to 48v while I am changing batteries and replace controller/solenoid and replace the motor in the future (I think this is possible).

Option 3. Electronic Motor Products advertises a switchable motor that allows you to switch between torque and speed, and I think they said that you can keep your stock controller.
Option 3.1. Buy this motor, then upgrade controller later
Option 3.2 Buy this motor, and go to 48v system. (do I need to upgrade controller at this point?)

Option 4. Sell this and buy new! (not really)

I would prefer a plan that would let me upgrade as I have money available, but I don't want to sacrifice performance by baby stepping my way through.

I know that the type of cart I have now is probably the worst for torque, so I am really leaning to the new motor route and I like option 3.

I want to do things right, so I'm all ears to advice and input.

Thanks

[cgtech]

Do the controller, cables, and solenoid option, with 36v batteries. That will get you speed & torque upgrade. Keep in mind going to 48v also requires a charger, and controller must be changed (not later, i was not clear if you understood that)

[ndhill1976]

Originally Posted by cgtech

Do the controller, cables, and solenoid option, with 36v batteries. That will get you speed & torque upgrade. Keep in mind going to 48v also requires a charger, and controller must be changed (not later, i was not clear if you understood that)

Thank you

[ndhill1976]

Any advice for a controller, I think I looked at the Alltrax 500 controller in the past.

I would like to buy a controller that would work well with a beefier motor in the future.

[cgtech]

Since you indicated you have a PDS (sepex/regen) cart, the XCT48500 (I suggest tuned to 400a for stock motor). That controller is easily capable of a motor upgrade, and a upgrade to 48v if you choose.

[JohnnieB]

Sounds like you have a 2004 TXT cart with a PDS type drive. (AKA - SepEX or Regen)

I have a 2008 PDS, which is identical with a 2004 except year it rolled out of factory.

My first upgrade was a complete set (10 cables) of 2Ga, silver soldered, high current cables.

Two of my tires were almost bald and all had slow leaks, so I replaced them with tires I thought would be 18.3" tall, which should have given me about 2% more speed at the cost of 2% less torque where rubber meets road, but they turned out to be 17.04" tall, which gave me 5% less speed with a torque gain of 5%.

Next was a controller and solenoid. I didn't know if I was going to up the pack voltage when I replaced the batteries, or if I did, was I going to 42V or to 48V. Aftermarket controllers will typically run on all of those voltages, but not all solenoids will, so I went with a super-duty 400A solenoid that will and ran it first at 36V, later at 42V and may go to 48V in the future. About $30 more initially, but saved about $70 when I upgraded to 42V.

Then I upgraded to a 42V battery pack using 7 x 6V-245AH batteries. My goal at the time was a 30+ mile range on a single battery charge, plus some additional run-time to compensate for battery aging, and I couldn't get that range with a 48V battery pack made up from the 8V batteries available at the time and I didn't want to go through the efforts needed to shoehorn eight 6V batteries under the seat.

The motor was the last thing I changed and that was a replacement rather than a planned upgrade. I did something dumb and ruined the original motor and had my lapse in good judgement not destroyed the stock PDS motor, I'd probably would be still be running it.

You already have 22" tires, so you have about a 18% torque loss and about a 22% speed gain, unless they are low pressure tires. (If they are the low pressure type than the torque loss is greater and the speed gain is less.)

An Alltrax XCT48400PDS (or XCT48500PDS) controller with a MZJ400 solenoid will give you about a 33% increase in torque, for a net gain over stock of about 15%, however that gain is mostly low end torque and you cart will still slow considerably due to the taller than stock tires.

To get less slowing on hills you need to increase torque throughout the RPM spectrum, so you have to go to a higher voltage battery pack, or a motor that has better high end torque, or both.

Personally, I'd upgrade the high current cables first, then the controller & solenoid, then up the battery pack voltage and at that point, you would probably know if a motor upgrade was needed or not.

[vagabond]

Cables first, either buy a set or make up your own using 2 gauge welding cable, then controller and solenoid, then batteries and charger DPI recommended, and then the motor if needed.
It always seem like we want a little more speed and or torque so pick the motor wisely.
Good luck with the build

[ndhill1976]

Thank you JohnnieB and vagabond.

I will most probably go the route that everyone has recommended.
2 (maybe 4) gauge cables, 400 or 500 controller, and 400 amp solenoid, then increase batteries and motor in the future.
I may even get some slightly smaller tires too. The ones I have a pretty worn, and they are low pressure 22" tires, which means that I lose extra speed and torque. I didn't know that low pressure tires caused this until you said something JohnnieB, but it makes sense.

[JohnnieB]

With 48V, 4Ga cables will suffice.

Mathematically, a tire with a height of 22" will produce a cart speed of 23 MPH with a stock controller & Motor & differential gears with a 36V battery pack, but it will only reach about 21 MPH or so at best due to the unavoidable loss of high end torque caused by the change in the final drive ratio. How much your tops speed is less than that, is how much additional load the low pressure tires are imposing on the drive system.

With high pressure (>20 PSI) tires that are 22" tall and a 48V battery pack (along with the needed controller and solenoid) your cart will have a top speed around 31 MPH with the motor spinning at 6000 RPM, which is what the max RPM in the XCT controller ought to be set for with a stock PDS motor.

With 21" tires it will be 30 MPH.

Of course, those speeds are scary in a short wheelbase, narrow track vehicle whose center of gravity has been raised 6" for tire clearance, but you can program the XCT controller to limit the motor RPM to a lower value.

Attached is a chart that gives you motor RPM per MPH of cart speed.
Find your measured tire height in the leftmost column and then multiply the number in the rightmost column by your max speed desired to get the RPM to set the max RPM slider in the XCT to.

[LBB]

Originally Posted by JohnnieB

Sounds like you have a 2004 TXT cart with a PDS type drive. (AKA - SepEX or Regen)

I have a 2008 PDS, which is identical with a 2004 except year it rolled out of factory.

My first upgrade was a complete set (10 cables) of 2Ga, silver soldered, high current cables.

Two of my tires were almost bald and all had slow leaks, so I replaced them with tires I thought would be 18.3" tall, which should have given me about 2% more speed at the cost of 2% less torque where rubber meets road, but they turned out to be 17.04" tall, which gave me 5% less speed with a torque gain of 5%.

Next was a controller and solenoid. I didn't know if I was going to up the pack voltage when I replaced the batteries, or if I did, was I going to 42V or to 48V. Aftermarket controllers will typically run on all of those voltages, but not all solenoids will, so I went with a super-duty 400A solenoid that will and ran it first at 36V, later at 42V and may go to 48V in the future. About $30 more initially, but saved about $70 when I upgraded to 42V.

Then I upgraded to a 42V battery pack using 7 x 6V-245AH batteries. My goal at the time was a 30+ mile range on a single battery charge, plus some additional run-time to compensate for battery aging, and I couldn't get that range with a 48V battery pack made up from the 8V batteries available at the time and I didn't want to go through the efforts needed to shoehorn eight 6V batteries under the seat.

The motor was the last thing I changed and that was a replacement rather than a planned upgrade. I did something dumb and ruined the original motor and had my lapse in good judgement not destroyed the stock PDS motor, I'd probably would be still be running it.

You already have 22" tires, so you have about a 18% torque loss and about a 22% speed gain, unless they are low pressure tires. (If they are the low pressure type than the torque loss is greater and the speed gain is less.)

An Alltrax XCT48400PDS (or XCT48500PDS) controller with a MZJ400 solenoid will give you about a 33% increase in torque, for a net gain over stock of about 15%, however that gain is mostly low end torque and you cart will still slow considerably due to the taller than stock tires.

To get less slowing on hills you need to increase torque throughout the RPM spectrum, so you have to go to a higher voltage battery pack, or a motor that has better high end torque, or both.

Personally, I'd upgrade the high current cables first, then the controller & solenoid, then up the battery pack voltage and at that point, you would probably know if a motor upgrade was needed or not.

Do you mind me asking what stupid thing you did to ruin the motor? :-)

As you prob know from the other thread, I'm trying to learn as much as I can quickly.