I need more torque

[branson]

I have a 500 amp alltrax advance motor part number 7124 or gl0-4001
Ratinng au2500. 48 volt 2 gague cables and solenoid.
I think the problem lies in the 25" tires I have on it with the stock gear ratio 12.44:1. When I first did the motor controller upgrade I had 18" tires. The torque was very good, then I got some 25" tires. Now it goes 30 mph and I want my torque back I was happy with 23 mph.
All I can find is 15:1 gears but when I play with the speed calculator I think I want about 18:1. Or should I be looking somewhere else to find my lost torque?
I would appreciate any ideas

[sportcoupe]

Sounds like you have a high speed motor and need a high torque motor. Give Eric or Vic a call at D&D, they can make you a motor that will go slower giving you torque back.

[branson]

7124 is a nivel part number it says it is a series high torque motor.
@ 36volts 8hp at 1800 rpm
@ 48volts 11.4 hp at 2400rpm
Maybe it is just not enough motor for what I want. I was planning on 23" tires but I got 25" for free and now that I have them I'm not going back

[sportcoupe]

They can claim "high torque" but it's just an off the shelf motor. The rpm readings listed are just where the motor makes max power. If you are doing 30 mph on 25" tires you are spinning that motor at about 5000 rpm. That is a lot closer to a high speed motor then a high torque.

If you really want to keep the 25's then it's either gear change or motor change for more power. I don't know what gears are available the "other" way. Most people gear for more speed, stock is 12.44:1 and gear changes are either 8:1 or 6:1, both for more speed.

If you install 15:1 gears that will lower your max speed to 25 mph at the same 5000 rpm. The cart will feel more torque also. How much is subjective to the driver.

A motor swap is more flexible. D&D can make you a custom motor that turns as little as 3400 rpm I believe. I think they ever might offer lower rpm motors as well. That 3400 rpm would put you at around 21 mph. Eric or Vic at D&D can give you exact numbers. The power increase would be very noticeable since you're willing to give up so much speed. .

[branson]

thanks sportcoupe I was afraid of that back when I got the motor and controller I was not nearly as knowledgeable as I am now. I believe I have this site to thank for that
now I just need to figure if I should get a motor or gear change. decisions decisions

[cgtech]

Stock RXV 16.99 ratio ring gear is very close to the axle housing, i doubt anything much higher than that is available. Stock RXV ratio makes a rxv very capable in sand and some hills IMO (as long as you are moving when you hit the hill). A curtis powered rxv with 22 or 23 (i forget which) VX tires and a tuned stock controller can do 30mph on solid ground AND 20mph in soupy wash sand, which i feel is pretty good for stock. You cannot run a stock rxv input shaft in a txt, so i put a rxv posi and ring gear and rxv intermediate shaft with a stock marathon input shaft and corresponding gear in mine. I didnt count the teeth, but it yeilded me a ratio of about 14.5:1. I will be running 22" kenda pathfinders on my el-cheapo crashed marathon yard buggy, hope the ratio is high enough.

[Epb]

Could you get the controller modified for higher amps or get new controller 700??? To get the torque back. Thread after thread is amps= torque and volts= speed.

[sportcoupe]

There is a FSIP 700A controller. You will never use all of that because max amps is only on initial takeoff and drops rapidly after that. He might notice a slight increase but probably won't. Some say golf cart batteries can't even push 700A so that may be a consideration also.

A motor swap will be very noticeable for what the OP is asking (give up mph for tq). He can sell old motor to recover some money spent.

[branson]

I'm not really considering a new controller I think 500 amba is good enough. it's looking like I may end up getting a new motor but I'm not quite sure yet. it just seems strange to not lower the gear ratio if u have such big tires. but I think with the exception of the imaginative engineering rear end. the lowest gear ratio I can get is 15:1

[yurtle]

Are smaller tires completely out of the question? Borrow a set of smaller ones - just for the back, and see how it affects torque.