Need more torque on 6:1 gears

[720Deere]

Maybe an EMP 2 stage motor? 6:1 is a pretty steep ratio to overcome. Seems to me like the torque loss would be something like installing 36" tires with the stock gear set. In fact you overall effective ratio is higher than the stock 12.44:1 with 36" tires. At your peak speed of 45 mph, you were spinning the motor 5000 rpm but you obviously have too little torque to maintain that speed. It would take just over 6500 rpm to reach 45 mph with 8:1 gears. You are probably giving up some torque with the speed motor, but really your weak link is the 6:1 gears. With those gears, you have done the equivalent of taking a pickup with 4.10 gears and installing a 2.00 gear set. That truck is going to have a lot of trouble trying to tow a heavy trailer with the 2.00 gears!

[YzBrad99]

Originally Posted by chloe

Maybe I'm just hung up on the throttle response you indicated. I'm assuming you aren't getting any trouble codes. Have you checked the linearization of the throttle?

No trouble codes. Controller is working perfect. Just thinking I need to go with more of a less top speed motor and get more torque.

[YzBrad99]

Originally Posted by 720Deere

Maybe an EMP 2 stage motor? 6:1 is a pretty steep ratio to overcome. Seems to me like the torque loss would be something like installing 36" tires with the stock gear set. In fact you overall effective ratio is higher than the stock 12.44:1 with 36" tires. At your peak speed of 45 mph, you were spinning the motor 5000 rpm but you obviously have too little torque to maintain that speed. It would take just over 6500 rpm to reach 45 mph with 8:1 gears. You are probably giving up some torque with the speed motor, but really your weak link is the 6:1 gears. With those gears, you have done the equivalent of taking a pickup with 4.10 gears and installing a 2.00 gear set. That truck is going to have a lot of trouble trying to tow a heavy trailer with the 2.00 gears!

I think the motor I have says at 48 VOLTS it will turn 7500 rpms, but don't hold me to that. Granted, I would never have enough torque to get there. I can't find any 48 volt specs on this motor anywhere anymore.

[720Deere]

Well from what I have read, speed motors loose 10-15% torque over stock. It seems like your overall loss is a lot more than that if you are only hitting 5000 rpm.

[YzBrad99]

Originally Posted by 720Deere

Well from what I have read, speed motors loose 10-15% torque over stock. It seems like your overall loss is a lot more than that if you are only hitting 5000 rpm.

I'd say easily lost about 20% torque with the motor. I looked into the EMP Stage 2 motors but all the EZGO series cart motors were for 36 V. Maybe I can contact them and see if they can make it work for 48V. One nice thing about the 6:1 gears is if im just taking it easy, the battery pack lasts forever because the motor rotations are like half.

[sportcoupe]

Originally Posted by YzBrad99

Rear disc conversion.

Talked to D&D. Vick said he can make a motor but i'll lose about 10 mph. 35 would still be nice but I was hitting 30mph with just this motor on 48 volts and stock gears so looking to be around 40mph max.

Just looking for that extra torque from 0-5mph. 8:1 gears isn't out of the option but would it really help that much?

Check out my high speed gears 48v PDS cart. With a custom D&D motor I got ~36 mph on 18" tires. Plenty of torque too that slightly spun the tires on paved corners if there was ANY loose sand or small pebbles. If you give up a few more mph then you would get more torque back.

D&D motor was an ES-5H-50. Vic or Eric know this one.

http://www.buggiesgonewild.com/elect...r-upgrade.html

[chloe]

The EMP would be a good choice. I have one and the difference between torque and speed settings is noticeable.

If you can find someone willing to let you conduct a test with their 24 inch tires you would be able to determine the effects of regaining that 20% difference back. Actually a set of 22 inch tires, which should fit without issue, should be enough to let you know if that's the problem.

[dmi518]

my emp 2 speed runs well on 48 volts. my cart has 14:7 gears the previous owner installed, it will stand on the hitch with 23" tires . a lot of torque but i am still not sure the my emp 5.4 would make up for those gears. if you were closer i would tell you to come to my shop and we could try it just to see
i am planning a few gear swaps to see what it likes best.

[YzBrad99]

[YzBrad99]

Originally Posted by chloe

The EMP would be a good choice. I have one and the difference between torque and speed settings is noticeable.

If you can find someone willing to let you conduct a test with their 24 inch tires you would be able to determine the effects of regaining that 20% difference back. Actually a set of 22 inch tires, which should fit without issue, should be enough to let you know if that's the problem.

How much different is the torque setting to the speed setting. A huge difference or just a little? I've never been in a cart with this motor.