1998 EZ-GO TXT Series 36V Upgrades and Performance Issues

[adog33]

Already been emailing Scotty, but thanks for the reminder.
Always good to support small business and forum members.

[adog33]

Speaking of the 48V Conversion.

-Does anyone have images of extra batteries mounted in the rear baggage area?
Want to find a clean way to mount them.

-Any concerns about the extra weight and support the batteries?

[busman9]

Might be easier to sell your 6V batteries and buy 6-8v. That is what I did and could not be happier

[adog33]

If we take my complaint about torque out of the equation for a second and look
at my motor specs.

AMD 7122
4.0 Hp, 4400 RPM at 36 VDC
AMD advertises 20 MPH with stock controller. I am assuming that is on stock tire size.


I am getting about 20-21 on 23" tires. Does that seem correct? Want to make sure I am not overlooking a misdiagnosed problem.

[JohnnieB]

The 20MPH would be with stock height (18") tires and stock (12.44:1) gears, so the motor would be spinning at 4646RPM.

Mathematically, at 4646RPM with 12.44:1 gears and 23" tall tires, the cart ought to be traveling at 25.6MPH, but due to the 21.7% torque loss due to the change in the final drive ratio (16.59:1 to 12.98:1), the motor cannot not spin that fast with a 36V battery pack, so it won't reach the theoretical speed. However, I'm not sure if the 20-21 MPH you are getting is as high as it should be or if there is something hold the cart back.

According to Carlisle, the tires have an inflation pressure of 20PSI or more. Try a test run at the max inflation pressure embossed on the sidewall and see if it'll go faster.

Like BobBoyd said, you did a double whammy on the torque where rubber meets road, High-Speed motor and Tall tires.

FWIW: The max RPM a series motor will spin is RPM at which the motor is capable of drawing the amps needed at the applied voltage to produce an amount of torque equal to the mechanical drag placed on the motor. If the mechanical drag increases, the motor will slow until it is capable of drawing the needed amps to produce the needed torque to equal the drag.

[kernal]

Originally Posted by adog33

If we take my complaint about torque out of the equation for a second and look
at my motor specs.

AMD 7122
4.0 Hp, 4400 RPM at 36 VDC
AMD advertises 20 MPH with stock controller. I am assuming that is on stock tire size.


I am getting about 20-21 on 23" tires. Does that seem correct? Want to make sure I am not overlooking a misdiagnosed problem.

I have the GE version of that motor. At 36v it would push my TXT, which is heavy with 18" tires, to 20mph under optimum conditions. So getting only a tiny bit of extra speed with 23" tires doesn't surprise me and seems to track with other peoples experience over time. I would also expect, based on my experience, that your cart would slow more than mine on an incline. A higher amp controller might abate the bogging down on the incline slightly but not by much I suspect.
The 48v volt conversion transformed my cart. If you want a noticeable increase in performance, you really need to go 48v in a series cart IMO. I'm not a fan of the extra batteries in the bagwell. Besides the extra complexity, you are carrying around the equivalent of a small human ALL the time.

[adog33]

Originally Posted by kernal

I have the GE version of that motor. At 36v it would push my TXT, which is heavy with 18" tires, to 20mph under optimum conditions. So getting only a tiny bit of extra speed with 23" tires doesn't surprise me and seems to track with other peoples experience over time. I would also expect, based on my experience, that your cart would slow more than mine on an incline. A higher amp controller might abate the bogging down on the incline slightly but not by much I suspect.
The 48v volt conversion transformed my cart. If you want a noticeable increase in performance, you really need to go 48v in a series cart IMO. I'm not a fan of the extra batteries in the bagwell. Besides the extra complexity, you are carrying around the equivalent of a small human ALL the time.

Kernel, Did you run the cart on 36V with an upgraded controller? If, so did it improve your results over the OEM 275 Amp?


My buddies cart has the GE variant like you, AllTrax AXE 500 AMP on 36V, and the cart much more torque / acceleration than mine.

[Sir Nuke]

adog......like yourself, I had bought a new set of batteries when I got my cart, just so it wound run. THEN I found BGW and found out what I needed to make my cart perform and last. My cart is a series drive as yours is.....you can see in my sig everything I added, except it was kept at 36v.....and ran great, then after 4 1/2 years, I bit the bullet and bought a set of 6-8v (48v) batteries. All I needed to do was to change out the resistor and diode on the solenoid, and change 1 or 2 settings in the controller. PIECE OF CAKE! and the improvement was like night and day to me! I gained 5 mph and a TON of torque!

[kernal]

[QUOTE=adog33;1472489]Kernel, Did you run the cart on 36V with an upgraded controller? If, so did it improve your results over the OEM 275 Amp?


My TXT is technically a shuttle (factory built rear seat, 80"canopy etc) and as such came with a Curtis non programable, 24-36v, 400amp controller and a 1.87KW motor instead of the standard 275 amp controller and the 1.49 KW motor . So I can't relate in personal experience with the baby controller other than this:
I operate in a purpose built golf cart community. Over 18 years my cart has always been just a little faster (2-3mph) on the flats then the standard 36v carts and would hold speed just slightly better on the inclines. It would pull maybe 1-2 cart lengths over 100 yards up an incline. Probably due to the motor not the controller.
Going to the GE speed motor upped the top speed to 20 (increase of 3mph) with no effect otherwise.
The controller was changed to an Alltrax SPM (400amp) and other than being adjustable and 48v capable nothing changed again--as expected.
At 48v top speed increased 2-3 mph (less than expected) but it gets there quickly. The big difference was it's ability to hold speed on the inclines. It is not an embarrassment now in traffic with the 48v sepex carts and is faster on the flats because it's not restricted.

Based on what you have said, I think the motor is giving you what it's supposed to but I'm suspicious of the controller. I'm puzzled by the 1-2 second delay you mentioned post#1. My cart was never like that. It is and always was very responsive to throttle. I've driven lots of TXTs both sepex and series and never run across that delay either.

Also, based on other's experience in my community and what has beed said in this thread, I'm reasonably confident the 23" tires are killing your acceleration and hill climbing performance.

[adog33]

[quote=kernal;1472525]

Originally Posted by adog33

Kernel, Did you run the cart on 36V with an upgraded controller? If, so did it improve your results over the OEM 275 Amp?


My TXT is technically a shuttle (factory built rear seat, 80"canopy etc) and as such came with a Curtis non programable, 24-36v, 400amp controller and a 1.87KW motor instead of the standard 275 amp controller and the 1.49 KW motor . So I can't relate in personal experience with the baby controller other than this:
I operate in a purpose built golf cart community. Over 18 years my cart has always been just a little faster (2-3mph) on the flats then the standard 36v carts and would hold speed just slightly better on the inclines. It would pull maybe 1-2 cart lengths over 100 yards up an incline. Probably due to the motor not the controller.
Going to the GE speed motor upped the top speed to 20 (increase of 3mph) with no effect otherwise.
The controller was changed to an Alltrax SPM (400amp) and other than being adjustable and 48v capable nothing changed again--as expected.
At 48v top speed increased 2-3 mph (less than expected) but it gets there quickly. The big difference was it's ability to hold speed on the inclines. It is not an embarrassment now in traffic with the 48v sepex carts and is faster on the flats because it's not restricted.

Based on what you have said, I think the motor is giving you what it's supposed to but I'm suspicious of the controller. I'm puzzled by the 1-2 second delay you mentioned post#1. My cart was never like that. It is and always was very responsive to throttle. I've driven lots of TXTs both sepex and series and never run across that delay either.

Also, based on other's experience in my community and what has beed said in this thread, I'm reasonably confident the 23" tires are killing your acceleration and hill climbing performance.

Kernal, thanks for the input.

Yes, I agree that something is likely going on with my controller. Without a Curtis programming tool it's hard to diagnose. The lack of acceleration and the delay in take off, in my opinion all point to the controller.

My plan is to order an AllTrax from Scotty, and see how the results are. I am
hoping I will be happy. As I stated before my buddy has the same cart, GE variant motor, AllTrax 500, and his Cart moves out!

If I still want more power I will likely remove my accessory 12V, add 1 6V there and another in the rear luggage area. Then install a 12v converter for the lights and accessories.