2000 EZGO TXT Series - Upgrades for speed

[jmatlock88]

Hello, I have a 2000 EZGO TXT with a series controller. This is a neighborhood cart that I am looking to make some upgrades for speed. No lift. No large tires.

I would like to be able to adjust the speed for when the kids drive the cart.

I am looking to keep the 36V batteries and the stock motor for now and upgrade them on the next battery replacement cycle. For this reason, I would like to buy a controller capable of these upgrades (400A to 600A, 36 to 48V)

I have a 13pc 2 gauge wiring kit already on order.

Regarding the heavy duty forward and reverse switch, is Amazon ASIN: B07R3FQ1F9 a good choice?

Regarding the controller, I am looking for recommendations maybe between an Alltrax unit with a bluetooth module or the Navitas TSX 3.0. I would like to know what controller PN and harness adapter PN are appropriate.

Any other recommended modifications?

Thanks!

Cart
2000 EZGO TXT with a series controller
Manf Code F2000

Motor
PN 73124G02
PN A95-4005A
36V DC
Rating AU2500 FLT SPD 11/9/99

Batteries
36V T-105 Trojan 05-12-2018

Solenoid
SAS4303 36V 11k USA

[JohnnieB]

Only three ways to increase the speed of a series drive.
1. Increase the battery pack voltage. (increases both speed and torque)
2. Change the final drive ratio by changing tire height or differential gears. (Increases speed but reduces torque.
3. Change the motor.

[jmatlock88]

Thank you - Would you mind making a recommendation on an upgrade package? Here are the options that I think might be available to me.

Option 1: All new 48V batteries
$1200 Replace all six 6V batteries with 8V batteries
-$400 Sell my six 6V batteries which are 2 years old
$180 Upgrade to a 36V/48V solenoid
$500 Change to a stock series 48V motor controller
$250 New 48V Charger
$48 New 48V charging socket on the cart
$99 New HD forward and reverse switch
$0 Keep the same stock 36V motor
$152.47 Upgrade to 2ga 13pc wire set
TOTAL $2029
Top Speed 19 mph?
19mph - 12mph = 7mph gained.
$2029/7mph = $290/mph gained

Option 2: 7th battery?
$200 Because my batteries are still good, is there an acceptable option to add a 7th 6V or 8V battery to achieve 42V or 44V?
$180 Upgrade to a 36V/48V solenoid
$500 Change to a stock 48V motor controller
$250 New 48V Charger
$48 New 48V charging socket on the cart
$99 New HD forward and reverse switch
$0 Keep the same stock 36V motor
$152.47 Upgrade to 2ga 13pc wire set
TOTAL $1429
Top Speed 19 mph?
19mph - 12mph = 7mph gained.
$1429/7mph = $204/mph gained


Option 3: Upgrade to a Plumquick 36V Sorcerer motor
$655 New Plumquick 36V PQ36-422 motor
$0 Keep the stock 36V controller
$180 Upgrade to a 36V/48V solenoid
$99 New HD forward and reverse switch
$152.47 Upgrade 2ga 13pc wire set
TOTAL $1086
Top speed 20-22mph
20mph - 12mph = 8mph gained.
$1086/8mph = $136/mph gained

Option 4: Upgrade to a Plumquick 36V Desperado motor
$705 New Plumquick 36V PQ36-419 motor
$625 Upgrade to an aftermarket 36V-48V controller
$180 Upgrade to a 36V/48V solenoid
$99 New HD forward and reverse switch
$152.47 Upgrade 2ga 13pc wire set
TOTAL $1761
Top Speed 25-27mph
25mph - 12mph = 13mph gained.
$1761/13mph = $136/mph gained

[JohnnieB]

Another option is to get parts that will run at 36V now and 48V later, and run at 36V until you need to replace the batteries. Multi volt controllers and solenoids exist, not sure about charger.

Get cables for 8V batteries, they are longer since the terminals on 8V batteries are both on same side. 8V battery cables will work for 6V batteries, but 6V battery cables won't be long enough for 8V batteries.

Don't have to change cart's 36V charge receptacle to a 48V one, the original 36V one will work at 42V, 48V or higher. Not voltage sensitive. The only issue is your 48V charger can be plugged into a cart with a 36V battery pack, but that isn't much of an issue unless you have people "borrowing" your charger.

The only true HD F/R switch out there costs about $170: https://www.cartsunlimited.net/f---r--switches.html

However, any mechanical F/R switch is the weakest point in a series drive. Think about replacing it with a reversing contactor.

Look at other motors. There are a lot to choose from and they can be custom wound for your specific application.

The trick is to figure out what you want or need the cart to do and then build towards that goal.

[jmatlock88]

Originally Posted by JohnnieB

The trick is to figure out what you want or need the cart to do and then build towards that goal.

The goal of this build is to determine and then implement the set of modifications to an EXGO TXT Series cart that will result in the lowest invested dollar per gained mph.

Originally Posted by JohnnieB

Another option is to get parts that will run at 36V now and 48V later, and run at 36V until you need to replace the batteries. Multi volt controllers and solenoids exist, not sure about charger.

I think I have found the 36/48 controllers and solenoids. What motor would you recommend that would be compatible with 36V and 48V?

Originally Posted by JohnnieB

Get cables for 8V batteries, they are longer since the terminals on 8V batteries are both on same side. 8V battery cables will work for 6V batteries, but 6V battery cables won't be long enough for 8V batteries.

Thank you - advice for 8V wire kit is implemented.

Originally Posted by JohnnieB

Don't have to change cart's 36V charge receptacle to a 48V one, the original 36V one will work at 42V, 48V or higher. Not voltage sensitive. The only issue is your 48V charger can be plugged into a cart with a 36V battery pack, but that isn't much of an issue unless you have people "borrowing" your charger.

I'm thinking swapping in a 48V port onto the cart is about the same level of difficulty as changing out any new 48V charger's connector down to a 36V version. So I think I will just stick with changing the port on the cart.

Originally Posted by JohnnieB

The only true HD F/R switch out there costs about $170.
However, any mechanical F/R switch is the weakest point in a series drive. Think about replacing it with a reversing contactor.

Thank you for this reference. I cancelled my order for a heavy duty F/R switch and will order the SW202 reversing contactor from cartsunlimited.

Originally Posted by JohnnieB

Look at other motors. There are a lot to choose from and they can be custom wound for your specific application.

I'm definitely needing some additional advice on selecting a motor and what I should be looking for.

[jmatlock88]

OK, I just ran across some posts from Sir Nuke (2007 EZGO TXT, Alltrax SPM-48500 500A controller, HD F&R Switch, 400A SD Solenoid, 2 ga cables, AMD 7126 "Raptor" motor 6.1HP 5330RPM). With this combo and 36V he was getting 27mph with 23" tires. With this combo and 48V he was getting 30mph with 23" tires.

Option 5: Upgrade to an AMD 7126 Raptor motor at 36V and ok to upgrade to 48V later
$610.95 AMD 7126 "Raptor" motor 6.1HP 5330RPM from diygolfcart
$508 Alltrax SPM-48500 500A controller from evdrives
$180 Upgrade to a 36V/48V solenoid
$160 Curtis Albright 400Amp Single Pole Double Throw Contactor from buggiesunlimited
$152.47 Upgrade 2ga 13pc wire set
TOTAL $1611
Top Speed 21 mph with stock 18" tires to maintain apples-to-apples comparison with the other options (Sir Nuke 27mph was achieved with 23" tires)
21mph - 12mph = 9mph gained.
$1611/9mph = $179/mph gained

[kernal]

Originally Posted by jmatlock88

OK, I just ran across some posts from Sir Nuke (2007 EZGO TXT, Alltrax SPM-48500 500A controller, HD F&R Switch, 400A SD Solenoid, 2 ga cables, AMD 7126 "Raptor" motor 6.1HP 5330RPM). With this combo and 36V he was getting 27mph with 23" tires. With this combo and 48V he was getting 30mph with 23" tires.

Option 5: Upgrade to an AMD 7126 Raptor motor at 36V and ok to upgrade to 48V later
$610.95 AMD 7126 "Raptor" motor 6.1HP 5330RPM from diygolfcart
$508 Alltrax SPM-48500 500A controller from evdrives
$180 Upgrade to a 36V/48V solenoid
$160 Curtis Albright 400Amp Single Pole Double Throw Contactor from buggiesunlimited
$152.47 Upgrade 2ga 13pc wire set
TOTAL $1611
Top Speed 21 mph with stock 18" tires to maintain apples-to-apples comparison with the other options (Sir Nuke 27mph was achieved with 23" tires)
21mph - 12mph = 9mph gained.
$1611/9mph = $179/mph gained

The Alltrax SPM controller was what was available when Nuke built his cart. It is an old model now and the current version is called the SR. More performance, better packaging (smaller that the SPM) etc. There are some package deals here: https://www.cartsunlimited.net/alltrax-sr-series--.html

[JohnnieB]

One of the things I've notice is that the stock speed you're listing (12MPH) is slightly below the EZGO specs of 13 to 14 MPH and that could mean the amp delivery system (Cables, contacts and connections, and brushes and batteries) might be a little tired, or the tires true height is less than 18", so break out a yardstick and level and measure the tire height.

The highest max recommended speed for most motors is 6500 RPM, which translates to 28MPH with 12.44:1 gears and 18" tall tires. You calculated 21MPH at 36V with the AMD Raptor which is 4878RPM and there is a 33.3% speed gain when you go to 48V, which kicks the motor speed up to 6500 RPM on level pavement, but will exceed it going downhill.

You might want to look into high speed banding for the motor, so it'll stay together at higher than 6500RPM.

[jmatlock88]

Originally Posted by JohnnieB

One of the things I've notice is that the stock speed you're listing (12MPH) is slightly below the EZGO specs of 13 to 14 MPH and that could mean the amp delivery system (Cables, contacts and connections, and brushes and batteries) might be a little tired, or the tires true height is less than 18", so break out a yardstick and level and measure the tire height.

Thanks, Johnnie. I have 205/50-10 tires which are theoretically 18" tall. But in reality I am finding them to be about 17.5" tall when they are inflated to 25psi. Tires are still in nice condition with good tread remaining.

I think you are correct that this cart is underperforming. Honestly 12mph is being generous. Since I just bought the cart two days ago, I've still got a pretty big punch list to work through (checking for brake drag, alignment, tire inflation, battery condition, etc.). And we are together working up the plan for replacing the amp delivery system (cables, reversing contactor, solenoid, motor, and possibly controller). Overall this cart is in very nice condition, so I am looking forward to upgrading the powertrain to match the appearance.

Originally Posted by JohnnieB

The highest max recommended speed for most motors is 6500 RPM, which translates to 28MPH with 12.44:1 gears and 18" tall tires. You calculated 21MPH at 36V with the AMD Raptor which is 4878RPM and there is a 33.3% speed gain when you go to 48V, which kicks the motor speed up to 6500 RPM on level pavement, but will exceed it going downhill.

Looks like there was an error in my approach. I used 5330 as the motor rpm when I referenced golfcartcatalogs website. For the sake of completeness, this is how I arrived at 21mph for Sir Nuke's 36V configuration: He reported 27mph with 23" tires. So, not being familiar with typical gear ratios for these carts, I calculated his gear ratio as follows:

GEAR RATIO = ( RPM * TIRE DIAM ) / (MPH * 336).

GEAR RATIO = ( 5330 rpm * 23 inches ) / (27 mph * 336) = 13.51:1

Then calculated his speed if he had 18" tires

MPH = ( RPM * TIRE DIAM ) / (GEAR RATIO * 336)

MPH = ( 5330 rpm * 18 inches ) / (13.51 * 336) = 21.135 mph

Originally Posted by JohnnieB

You might want to look into high speed banding for the motor, so it'll stay together at higher than 6500RPM.

Thanks for this tip. I will request this feature. Do you happen to know what my axle gear ratio is?

[jmatlock88]

Regarding underperforming, is there any fine adjustment to be made on this cart's throttle position unit to ensure the controller is seeing 100%?