Age old "torque vs speed"

[BIGBONVI]

I am almost content with the Torque I have with my current setup. It could use a little more on the hills but overall I am happy. BUT I want to go to 26" tires for ground clearance. I will upgrade to 48v but it will be a while as my batteries are only a year old. Being that I have a Pds, I am told there is only one option I have with d&d for increase torque. According to their site it should net about a 40% increase. Plum quick claims 20% in torque and speed with the bandit. If I switch to 15:1 gears and the bandit, I should have close the same torque but more speed than I would with the d&d. Am i correct in this thinking. If this won't be enough torque I will end up with gears and torque motor. Thoughts please.

[Sir Nuke]

although its not the ideal way, but seeing as your batteries are only 1 year old....you could jump to 48v now...... which controller do you have? is it in fact programmable such that you can in fact make the swap to 48v? just going to 48v alone will net you 30% more torque and speed.

[JohnnieB]

It gets a little tricky because all the information needed to do valid comparisons is not available, but in very general terms, motors (both SepEx and Series) in the same diameter and length cases that are wound for low end torque (Torque motors), will not spin as fast with the same applied voltage under the same mechanical load, as motor wound for high end torque (speed motors). However, by using a larger motor case, a motor can be wound to have more low end torque while retaining its high end torque (speed).

The diameter of a cart motor is more or less fixed because they have to mount to the differential, but the length can vary a bit. My motor (D&D ES-76-51) case is 9.74" long, generates 30% more torque that a stock PDS motor, yet maxes out at about the same RPM with same voltage and load applied.

For your application (exceptionally tall tires) a ES-63-49 might be a better choice. Its case is 10.50" long and has 40% more torque, but is a bit slower. However, with 26" tire, the mathematical increase in speed is 18% faster than what you are now getting with 22" tires, so it'll probably be acceptable.

Compared to stock height tires, you are losing 18% of the available torque with 22" tires and that will go to 31% with 26" tires.

With a 15:1 gears (Probably 14.92:1 actually), your torque loss is 2% on 22" tires and 17% on 26" tires.

Going to a 42V pack will increase both speed and torque by 16.7% while going to 48V will increase both by 33.3%.

As you see, you have more than one option, but with a 500A controller (unless the max amps are turned down some) and 22" tires, you are lucky the stock PDS motor is still alive.

Give D&D a call, they have motors that are not listed on their website, or give scottyb a call, he's a D&D dealer.

[BIGBONVI]

thanks for the info guys. the controller is DCX500PDS and came from scottieB. he programmed it with my current setup into consideration before shipping. 48v gives a lot of gain, but at a lot of $. i dont want to go 42v because i already have an additional giant battery in the back used for winch and acc.

[JohnnieB]

Originally Posted by BIGBONVI

thanks for the info guys. the controller is DCX500PDS and came from scottieB. he programmed it with my current setup into consideration before shipping. 48v gives a lot of gain, but at a lot of $. i dont want to go 42v because i already have an additional giant battery in the back used for winch and acc.

I put my seventh battery under the seat on the driver's side in front of the wheel well.

If you got the DCX500 kit from Scotty, it came with a super-duty solenoid (400A/1000A) that works at 36V, 42V and 48V, so upgrading to either 42V or 48V is the price of the batteries and a couple cables, plus a charger.

[BIGBONVI]

Ok so now considering 42v option. My batteries are 11 months old. Will adding a new 7th battery have any negative effects?

[scottyb]

I always advise against tires over 23 inches. They will negate a majority of the performance upgrades. Sure you can pull numbers from the internet, do some math, and stare at charts until you see what you want ... but I see these set ups drawing high amps & cooking the components over time. Not to mention rear axle, hub, and brake issues.
As for ground clearance, go around the downed tree not over it - lol
Bottom line, You will see more performance from your upgrades on smaller tires.
I hope this helps?

[JohnnieB]

Originally Posted by BIGBONVI

Ok so now considering 42v option. My batteries are 11 months old. Will adding a new 7th battery have any negative effects?

It would be best if you could find a used battery the same make and model and about the same age as the other six, but if you cannot, the new (seventh) battery will bear the brunt of the negative effects. Basically, it will quickly acquire the aging characteristics of the six older batteries.

[scottyb]

Originally Posted by JohnnieB

It would be best if you could find a used battery the same make and model and about the same age as the other six, but if you cannot, the new (seventh) battery will bear the brunt of the negative effects. Basically, it will quickly acquire the aging characteristics of the six older batteries.

True but finding a match just 11 months old is near impossible. So you buy new and resign yourself to 4 yrs of service from this battery as opposed to normal 5 yrs. It's a good way to go imho.

[BIGBONVI]

Thanks for the help guys.