2001 EzGo 36v Sepex Upgrade

[tekkski]

I recently purchased a 2001 EzGo 36v cart with the F/R switch on the dash and the tow switch under the seat. I might be very lucky,based on what i have read, but the cart with me, my wife and my two little kids tops out at 18mph. (GPS'd with Waze)

I'm looking for that 22-23 mph range. (25mph would be great) This is so I am not impeding traffic on some of the neighborhood roads we will be on briefly. I have about $750 to play with. (but might be able to bribe the wife for a couple more $$)

I have been up and down many posts but most of them focus on the series motors. I have also checked out carts unlimited and their page is very helpful but mostly talks about 48v carts and what you can expect there. I believe it mainly says to add a 2nd battery for 42v in regards to the 36v cars.

I'm hoping before I spend a bunch of money some Sepex owners can chime in on what they are seeing after these types of upgrades. Lessons learned?

I believe I am on stock tires. They have the SS hubcap on them but I will measure total overall dimension when I get home. (I want to go bigger later)

I'm looking at:
item #5 XCT400PDS
opt 4: xtc400 + 200 sol + 2g cables + meter & keyplate + FN2: $788
or
Item #6 XCT500PDS ( future proof for better motor?)
opt 4: 500/400/mounts.2g cables/ meter & keyplate/ FN2: $868

Anyone have experience with what I can expect that on stock tires and 36v? I certainly am close at 18mph. Hope that at the $800 price point I can get that extra 5mph with those upgrades. Most importantly is that overkill? Can I cut some stuff out and save $$ to get to where I want to be: 22-25mph? $600 ish would make much happier.

My end game:
I will EVENTUALLY will add at least 1 more 6v battery, for 42v but want the upgrades at 36v initially. 20-22" tires. Somewhere over 22mph is the goal. 25 would be preferred. (I usually cruise around 12 mph with my kids)

Thank you for any advice and shared experience in advance.

[kgsc]

xct400 or 500 will get you to 22-23 on good stock tires as long as the pack it okay. 4ga wire is good with the 400 but should probably use 2 with the 500. As for upgrades later getting the 500 and turning it down for now would not be a bad idea and you can get a solenoid that will operate at 36-48 volts as well. Unless you have some major hills you probably would be happy with the 400.

[Timberwolflt]

If you’re getting 18mph you’re already operating on an upgrade... I’d find out what it is... either bigger than stock tires or an upgraded controller or maybe even a speed ‘chip’

And now for an unsolicited opinion... these carts aren’t really designed for a lot of speed... they lack sufficient caster and tend to be darty at higher speeds... you may want to invest in a seatbelt upgrade cuz it don’t take much to sling a miniature passenger out of their seat

[tekkski]

kgsc,
Thank your for the reply! It is very flat around here. If the 400/solenoid and stock wires can get me to 22-23. Maybe that is the way to go.

Originally Posted by Timberwolflt

If you’re getting 18mph you’re already operating on an upgrade... I’d find out what it is... either bigger than stock tires or an upgraded controller or maybe even a speed ‘chip’

And now for an unsolicited opinion... these carts aren’t really designed for a lot of speed... they lack sufficient caster and tend to be darty at higher speeds... you may want to invest in a seatbelt upgrade cuz it don’t take much to sling a miniature passenger out of their seat

You are probably right. I'll measure tires and get the model #'s tonight.

As for the unsolicited part, it is appreciated. I'm not looking to learn lessons the hard way. I will be building a custom seat for the kiddos in the rear but the cart is currently equipped with seat belts as well.

[JohnnieB]

Sounds like you have a 2001 TXT PDS with a "Speed" chip installed, which is actually a 5-pin molex connector with red wires shorting pins 1&5 and 2&3, which puts the stock PDS controller in what is known as "Freedom" mode and typically has a top speed in the 18MPH to 19MPH on stock height (18") tires with a 36V battery pack that is in good health and high current cables in good condition.

The stock PDS controller (Curtis 1206MX) limits the motor to about 4400RPM, which is roughly 18.9MPH on 18" tall tires and the stock 12.44:1 gears in the differential. An Alltrax XCT48x00-PDS allows the user top set the m ax motor RPM up to 8000RPM, which is greater than the the max recommend RPM for most sepex motors. (Typically 6000RPM or 6500RPM is the max RPM recommendation for most motors)

Unfettered by RPM limiting, a stock PDS motor will spin up to about 5600RPM when fed by a 36V battery pack, which is 24.1MPH on stock height tires and stock gears.

Upping the battery pack to 42V ups the RPM the motor will reach by 16.7% or a bit over 6500RM, which is about 28MPH. A 48V pack will take the max RPM even higher, into the danger area for spinning the motor too fast, but it can be limited to a safe RPM by the XCT controller. (The advantage to going to 48V vs 42V is better torque and not slowing as much going up hills.)

As for tires, try to stay at 20" or less so you don't have to lift the cart and make an already unstable vehicle more unstable by raising the center of gravity of a short wheelbase, narrow track vehicle.

[kgsc]

Just as a quick test, turn the key off then flip the fnr switch from n to r 5 times then back to n. Count the number of beeps. That will put the cart in diagnostic mode and also tell what chip is in it. Flip to tow then back to run to get it back to normal.

[tekkski]

JohnnieB you nailed it, it is in "freedom" mode!

Here is what I found out:

2001 EzGo Txt PDS
Batteries: 6x 6v - US2200 by U.S.Battery: 232AH @ 20hr, 3 years old - seem ok
Wires: #4 SAE Copper 105 Centigrade (Awesome shape)
Tires: Kenda 18x8.5-8, 4 Ply, 22psi, Actual Measurement: 16.5"
Motor: #73124G08, DE8-4001, 36v, Class H, Rating: AU2500 FLT SPD 02/09/01, Advanced U.C Motors, Inc, SN 52332
Solenoid: W-R/RBM, 70-120224-5 Coil, 36 VDC Cont.
Rear End: Dana Spicer, 02-20-2001, 2B, 012AJ1841, 73669GO1, S.N 1258303
Controller: Curtis PMC, PN 73326G02, SN 1051-P060142
Chip: Molex Connector, 1/5 pins connected, 2/3 pins connected

I can't believe I am getting 18mph on 16.5" tires. Thank you for the tip on 20" tires. I would rather not do a lift. Are 20.5" ok? Or does it really have to be 20".

KGSC,
4 beeps in diagnostic mode.

All,
XTC400 and 200a solenoid? ($509) Or do I really need the 2awg cables as well? ($699) I hope that would includes all of the cabling I would need; batteries, motor, etc. My current 4awg cables are in great shape. It gets hot here so I will add the fan ($42).

Option:
Thinking to maybe bite the bullet and get a 7th battery so I'm not messing with things twice and choose the 42v stock motor option. Not upgrading the cables would pay for that 7th battery... but then I will need another charger... are those readily available? I'm guessing the stock motor can't handle 48v?

[cgtech]

You have done the research, commendable for you! I don't know the part number for your solenoid, but if it's a small silver can, it needs to be better. If your cables are all as good as stated, they are fine. On one condition, if the big cables to the motor are just as big as the rest. (The big cables are limited by the smallest/weakest one in the system, specific to the motor). Excluding the smaller ones to its field circuits. (Those 2 can be smaller). Basically it works like this, any cables that used to be 6g should all now be 4g or 2g. If your battery cables are 4g, the two big cables to the motor need to be 4g as well (same rule applies if your battery cables are 2g). The smaller "field cables" are allowed to be smaller in a Sepex system like yours because they don't ever have to do "full duty" like the big cables do. They will never have to carry full amp load for more than a few seconds, their duties will never likely exceed 50a for short bursts, and their typical load is between 5 & 20 amps, depending upon speed. I find it a joke when the rookie makes those wires giant 2g in their Sepex upgrade (they often brag about it). As long as the smaller field wires are in good shape, they are just fine.

[JohnnieB]

Originally Posted by tekkski

------------------
All,
XTC400 and 200a solenoid? ($509) Or do I really need the 2awg cables as well? ($699) I hope that would includes all of the cabling I would need; batteries, motor, etc. My current 4awg cables are in great shape. It gets hot here so I will add the fan ($42).

Option:
Thinking to maybe bite the bullet and get a 7th battery so I'm not messing with things twice and choose the 42v stock motor option. Not upgrading the cables would pay for that 7th battery... but then I will need another charger... are those readily available? I'm guessing the stock motor can't handle 48v?

Cables: The 4Ga cables will most likely be fine. There are a total of 10 high current cables and they should all be at least 4Ga. 2Ga are needed for high amp draw situations such as very tall tires combined with heavy loads and steep hills. High torque aftermarket motors also benefit from thicker cables.

The Yardstick for 4Ga cables being thick enough is whether they are hot or not after a hard workout. I use 10°F above air temperature as the go/nogo point.

Solenoid: The contracts of a 36V W-R 70 series are rated at 50A continuous. (Spec sheet attached). That is too small for even a stock PDS controller.
Go at least 200A on the contacts rating. However, if you might go to 42V or 48V, get a solenoid that will operate at all of those voltages and the on;ly one I know of is the MZJ400 with a 48V coil. (I've used the one I have at 36V and 42V so far and planning to go to 48V the next time I replace my batteries and they are going on 5 Y.O.

Pack voltage: 42V is, or at least was, the sweet spot for PDS carts when Alltrax DCX controller were being used. The DCX did not have RPM limiting and 42V will spin a stock motor to the max recommended RPM and beyond. The introduction of the XCT family of controllers do have RPM limiting, so 48V battery packs can be used without over-revving the motor.

[tekkski]

cgtech,
I have checked and the 4 awg wires go all the way 2 the motor. The motor has 5 wires total. 3 thin and two of them 4 awg. One of the thin ones comes out of the back.

I found a mistake I made, that is the wires from the pack to the controller are NOT 4 awg. These will get upgraded to 4 awg or all of it to 2 awg.

https://imgur.com/a/MqyuOEi

JohnnieB,
On carts unlimited they only offer the XTC400 with the 200a (SW180) in the bundle with a 42v option for stock motor. Would that not cut it? This is the less expensive option I was hoping for @ only $509 with my 4 awg wires.

"item #5 XCT400PDS", option 2. https://www.cartsunlimited.net/alltrax-xct-sepex--.html