TXT PDS needs more torque

[Wevil]

I have a 2008 EZGO TXT with the PDS system. It is lifted with 22" tires and a rear seat. It is used for trail riding with some mud and hills, campground cruising with 4 adults and general fun for all. The drive system is stock except for the "freedom chip". This set up works great for flat ground cruising, but really lacks in the hills and mud. I have a fairly new 36v battery pack so I really don't want to go the route of different voltage right now, but would like the ability to upgrade later when it's time for new batteries. So, what would be the best place to spend the money? I'm thinking controller and motor? Anyone have suggestions to the best combo? I'm getting about 20mph out of the cart now and really don't need any more top end, just TORQUE! (If I get more top end I won't complain).

[CART-ZILLA]

Email scottyb get you an Alltrax xct 400 thats what i did ... I installed it and its night and day on torque..and you can go from 36-42-48 volts when you are ready!!

[JohnnieB]

The 22" tires are costing you about 18% of the torque the stock PDS motor produces.
Upgrading to an XCT48400PDS will up the speed on level ground some and up the torque by about 33% at the low end of the RPM spectrum, but won't help too much with how much the cart slows on hills while traveling at speed.

To keep the cart from slowing as much on the hills while cruising, you need to up the battery pack voltage or change the motor to one that produces more torque at higher RPM.

Theoretically, your cart should be getting a bit over 23MPH with 22" tires and a stock 36V PDS controller, but you are only getting 20MPH, so something is holding you back. If any of the high-current cables (there are 10 of them) is getting warm or hot, that may be the problem, or at least part of it. If the tires are the low pressure type (<10 PSI max inflation pressure), that could be another part of the problem.

If the high-current cables are stock, replace all of them with 4Ga or thicker.

Replace the stock solenoid with a super-duty 400A continuous/1000A peak solenoid, which will work at 36V, 42V or 48V.

Replace the stock PDS controller with an Alltrax XCT48400PDS controller.

Add a seventh 6V battery that is the same make/model as the other six and get a 42V DPI Accusense charger. (That will up the torque by about 17% throughout the RPM spectrum)

The stock PDS motor will be happy with that setup, but if you need more torque, go to an aftermarket motor.

If the cart goes too fast, you can limit the max RPM in the XCT controller to any lower speed you want without effecting the cart's hill climbing performance.

Here is some good info on things to take into consideration when upgrading a cart. (Note: A PDS is a SepEX drive system - starting about halfway down the page)
http://www.cartsunlimited.net/tech-help-upgrades.html

[Wevil]

It sounds like the next logical mod is the XCT48400PDS. JohnnieB- the cart is a bit over 20mph, I was just rounding numbers. I have upgraded all the wires to 4 gauge. Are we talking about the cart going near 30mph after this?

[MichaelClayshulte]

Definitely upgrade the controller and solenoid to 400 amps from scottyb prices can't be beat and the setup is awesome!

[scottyb]

30 mph !> Heavens no. XCT 400 PDS control will give 24 mph with 36v and 17% more with 42vv by adding a 7th 6v battery and 42v charger.

[JohnnieB]

Originally Posted by Wevil

It sounds like the next logical mod is the XCT48400PDS. JohnnieB- the cart is a bit over 20mph, I was just rounding numbers. I have upgraded all the wires to 4 gauge. Are we talking about the cart going near 30mph after this?

No, upgrading to a XCT controller probably won't change your cart's speed much, if any.

As Scotty mentioned, when going from a stock PDS controller to a XCT the top speed on level ground is about 24MPH with a 36V battery pack and 18" tall tires.

This is due to the PDS controller limiting the motor to a maximum RPM of about 4400RPM while the XCT will allow the motor to reach its maximum RPM for the voltage applied, which is about 5600RPM with a 36V battery pack.

However, your cart has 22" tall tires, which would (mathematically) yield 23.1MPH with the motor spinning at 4400RPM and your cart isn't going that fast, so the motor is not reaching the RPM limit imposed by the stock PDS controller. Therefore, eliminating the 4400RPM limit won't increase the cart's speed.

The motor in your cart is only spinning somewhere in the neighborhood of 3800RPM (20MPH on 22" tires) to 4000RPM (21MPH on 22" tires).

[Wevil]

You guys are really helpful. I think I'm going to purchase the controller/solenoid combo first, and then if I still want more go for a new motor later. I looks like I can get a bit of my money back selling the stock parts on ebay. That would make this upgrade pretty cost effective.

I think the cart is doing the full 23, I have never gps tested it. It will make tears come out of your eyes with the windshield down, and it's a bit faster than most stock carts.

[JohnnieB]

You can also post them here: http://www.buggiesgonewild.com/golf-carts-parts/