Increase top end speed

[Highspeedlowdrag]

I have a 2016 Club car Precedent with 23” tires, Navitas AC conversion kit (5kw motor and 600 amp controller), two 48V lithium ion batteries with 180ah. The cart currently runs 35 mph top end and sometimes 36.5 mph.
I would like to increase the top end speed (hopefully 45 mph). I live in south Florida so no hills to worry about. I just need to have enough torque to drive the cart on my truck if needed (I could load it on a trailer if needed).
I am considering to install 8:1 or 6:1 gears.

Does anyone know:
How much will the top end speed increase with the 6:1 and how much with the 8:1?
Will the torque loss be significant enough to affect driving on flat roads?
Can I make up for the torque loss with the Navitas controller setting?
Will the top end speed of 45 (if achievable) overheat the AC motor? (Navitas told me that the AC motor cannot be over reved with the golf cart but that was when I told them I had stock gears, 12.5:1).
The gears cost about $500 so I would like to know if i will get at least 8 mph increase. Thank you for your advice.

[Jake_Daddy]

A 6:1 will turn your tires twice as fast as stock 12:1 assuming your motor has the torque to do so, not sure if that would be the case because at the same time a 6:1 would also cut your current torque in half.

[fstop]

You won't get the complete theoretical speed increase by cutting your gear ratio in half from ~12:1 to 6:1. The motor won't be able to overcome vehicle weight, drag and other factors to double tire rotation, but should increase it significantly. My guess is you could probably hit the low to mid 40s like you want. But...

While hard to predict exactly, you will definitely lose significant torque and efficiency (range) at normal speeds. You can only adjust the parameters so much in the app - you will have them all maxed out but the motor / controller's hard-set limits will be reached and that will be all it can do as far as acceleration / torque (and it might be enough for you if peak speed is the primary goal). You'll also be increasing current draw / heat as it relates to your battery / bms / controller significantly.

If you want to not lose torque / acceleration / range, but increase all of those things, while also pushing a little beyond 45MPH on top simultaneously, I'd consider going 72v lithium. That was the route I chose (Onward, 23", Navitas 5KW, stock 12:1 gearing). I had a 48v lithium pack previously and moving to 72v is night and day in acceleration / torque / responsiveness. Also obviously adds top end - about 10mph in my case for a peak speed of 47mph under same ideal conditions where I could manage 37 with the 48v pack. Current draw / heat through battery / bms / controller can also be ~50% less than with 48v pack.

My terrain is flat also, and range at stock speeds is ~80 miles with some reserve in the pack (120ah). Less at higher speeds of course but still 65+ miles with my typical ~26-30mph cruising speeds.

I know you have a battery pack already but IMO you'll be giving up a lot to get that top end speed when it's possible to gain performance all the way around.

Another option to consider at least. Good luck!

[Highspeedlowdrag]

Originally Posted by Jake_Daddy

A 6:1 will turn your tires twice as fast as stock 12:1 assuming your motor has the torque to do so, not sure if that would be the case because at the same time a 6:1 would also cut your current torque in half.

Thanks for the reply. I’m still pondering if I want to risk losing torque, especially when I don’t know how much the loss of torque will affect the performance of the cart. Not sure if it’s a good trade off. Thanks for your input

[Highspeedlowdrag]

Originally Posted by fstop

You won't get the complete theoretical speed increase by cutting your gear ratio in half from ~12:1 to 6:1. The motor won't be able to overcome vehicle weight, drag and other factors to double tire rotation, but should increase it significantly. My guess is you could probably hit the low to mid 40s like you want. But...

While hard to predict exactly, you will definitely lose significant torque and efficiency (range) at normal speeds. You can only adjust the parameters so much in the app - you will have them all maxed out but the motor / controller's hard-set limits will be reached and that will be all it can do as far as acceleration / torque (and it might be enough for you if peak speed is the primary goal). You'll also be increasing current draw / heat as it relates to your battery / bms / controller significantly.

If you want to not lose torque / acceleration / range, but increase all of those things, while also pushing a little beyond 45MPH on top simultaneously, I'd consider going 72v lithium. That was the route I chose (Onward, 23", Navitas 5KW, stock 12:1 gearing). I had a 48v lithium pack previously and moving to 72v is night and day in acceleration / torque / responsiveness. Also obviously adds top end - about 10mph in my case for a peak speed of 47mph under same ideal conditions where I could manage 37 with the 48v pack. Current draw / heat through battery / bms / controller can also be ~50% less than with 48v pack.

My terrain is flat also, and range at stock speeds is ~80 miles with some reserve in the pack (120ah). Less at higher speeds of course but still 65+ miles with my typical ~26-30mph cruising speeds.

I know you have a battery pack already but IMO you'll be giving up a lot to get that top end speed when it's possible to gain performance all the way around.

Another option to consider at least. Good luck!

I like your idea. Sadly, I just purchased 2 48V lithium ion batteries that have 190ah. The batteries are awesome but I wish I knew about going to 72v before I purchased them. I would really like to make it work so I wonder if I can add a 24v battery to my current set up to make the 72v? Maybe in a parallel series circuit. I think I can keep the 48v in parallel and then add a 24v in series? I’m just not sure if I can do this with mixed voltage of batteries. Usually all the batteries would be kept the same voltage. I’m going to call BigBattery to see what they say but any advice you have on that would be great. Just to clarify, my 600 amp Navitas controller with 5kw AC motor will be able to handle 72v, correct? Thanks so much for the advice. You gave me some great input and I’m reconsidering the gears and thinking of changing the voltage IF I can add a battery. I’m willing to drop another grand on an extra battery but I can’t start from scratch as you know these lithium batteries are not cheap lol. Thanks again for your input.

[fstop]

Originally Posted by Highspeedlowdrag

I like your idea. Sadly, I just purchased 2 48V lithium ion batteries that have 190ah. The batteries are awesome but I wish I knew about going to 72v before I purchased them. I would really like to make it work so I wonder if I can add a 24v battery to my current set up to make the 72v? Maybe in a parallel series circuit. I think I can keep the 48v in parallel and then add a 24v in series? I’m just not sure if I can do this with mixed voltage of batteries. Usually all the batteries would be kept the same voltage. I’m going to call BigBattery to see what they say but any advice you have on that would be great. Just to clarify, my 600 amp Navitas controller with 5kw AC motor will be able to handle 72v, correct? Thanks so much for the advice. You gave me some great input and I’m reconsidering the gears and thinking of changing the voltage IF I can add a battery. I’m willing to drop another grand on an extra battery but I can’t start from scratch as you know these lithium batteries are not cheap lol. Thanks again for your input.

You're welcome.

There are others here who would be better able to tell you about adding another pack and rigging as you suggest. Though it is obviously easy to make 72v from multiple packs, the problem arises when charging or having the group under load, and the effects on the individual BMS units. As you know, it isn't just as simple as the old 6v or 8v batteries and adding a few more for more voltage.

WRT 72v and the Navitas - yes, no problem. My cart is a 2018 and everything in it from Club Car was able to handle the 72v no problem. The Club Car 12v converter that came in mine from the factory could handle up to 100v in fact. You'd need to check that stuff on your cart obviously and verify. I did have a high dollar HD solenoid in there (not stock) before going 72v, but it is a 48v rated unit. The Navitas can still be set to drive the solenoid coil with 48v though (which is how I have mine set). I bought a basic 72v solenoid in case there were issues, but there weren't.

EDIT: You say you have "2 48v batteries, 190ah". Are these 2 separate packs? Is each one a 48v 95ah pack? Trying to understand what exactly you have, but if you have (2) 16 cell packs, you could make (1) 24 cell pack from them, and it would be 72v, but your ah would be 95. Keep in mind though that KWH is what you need to be concerned with when comparing energy storage between different voltage packs. 95ah x 72v = 6,840wh, -vs- 190ah x 48v = 9,120wh. So 25% less total energy (range), but also less weight, and less current draw. You'd need another BMS unit (should be inexpensive) that is usable with a 24s (24 cells in series) LifePo4 pack.

Even with 25% less total energy, you'd likely still be way ahead in terms of range -vs- 6:1 or 8:1 gears, plus performance would be superior across the board.

[Highspeedlowdrag]

Yes, I have two separate 48v packs that are 95ah each. I really appreciate your advice. I wish I came on this forum before I purchased the batteries. I contacted BigBattery and they said their BMS does not go over 48v and there is nothing I can do. I know I could go with another company but I’ll wait until it’s time foe a new pack since I just purchased these. So I decided to be satisfied with 35 mph. Thanks again for the input. Much appreciated.

[Polie]

Sorry to necro post BUT you answered most of what I was researching. Lol I have the 72v eco ordered, same AC controller and motor, and 23" tires as well. What about running a 6:1 WITH all that? Currently even at 48v lead acid I can't have the dial turned up for than 50% or wifey starts to give me "the look" (rightly so. Her spine, neck, and shoulders have so much titanium the CIA was trying to open up trade relations)

Originally Posted by fstop

You won't get the complete theoretical speed increase by cutting your gear ratio in half from ~12:1 to 6:1. The motor won't be able to overcome vehicle weight, drag and other factors to double tire rotation, but should increase it significantly. My guess is you could probably hit the low to mid 40s like you want. But...

While hard to predict exactly, you will definitely lose significant torque and efficiency (range) at normal speeds. You can only adjust the parameters so much in the app - you will have them all maxed out but the motor / controller's hard-set limits will be reached and that will be all it can do as far as acceleration / torque (and it might be enough for you if peak speed is the primary goal). You'll also be increasing current draw / heat as it relates to your battery / bms / controller significantly.

If you want to not lose torque / acceleration / range, but increase all of those things, while also pushing a little beyond 45MPH on top simultaneously, I'd consider going 72v lithium. That was the route I chose (Onward, 23", Navitas 5KW, stock 12:1 gearing). I had a 48v lithium pack previously and moving to 72v is night and day in acceleration / torque / responsiveness. Also obviously adds top end - about 10mph in my case for a peak speed of 47mph under same ideal conditions where I could manage 37 with the 48v pack. Current draw / heat through battery / bms / controller can also be ~50% less than with 48v pack.

My terrain is flat also, and range at stock speeds is ~80 miles with some reserve in the pack (120ah). Less at higher speeds of course but still 65+ miles with my typical ~26-30mph cruising speeds.

I know you have a battery pack already but IMO you'll be giving up a lot to get that top end speed when it's possible to gain performance all the way around.

Another option to consider at least. Good luck!

[MikeinDallas]

I have a 2023 Onward HP Lithium XR battery set up and want to get to the 32 - 35 mph range. I'm considering a gear swap to the 6:1 from Apache and curious if you guys think I should get a 400 or 600 amp controller.

[TheCartBoy]

Originally Posted by MikeinDallas

I have a 2023 Onward HP Lithium XR battery set up and want to get to the 32 - 35 mph range. I'm considering a gear swap to the 6:1 from Apache and curious if you guys think I should get a 400 or 600 amp controller.

I see this is your first post, welcome!

You have a very modern club car that has CAN Bus integration between all the electronics. You can't just swap the controller and expect the cart to still work. Changing gear ratio and/or wheels is purely mechanical and the electronics won't know the difference. This is the way.