Went from 18" tires to 23" tires - still have same top speed

[ticklechicken]

Originally Posted by jjance

He should notice a difference with the 2awg cables.

I read this on another thread:

Originally Posted by JohnnieB

Tangible benefits are received from controllers over 275A.
With a 500A controller, a series wound DC traction motor will produce 82% more low end torque than it will with a 275A controller and with a 600A controller is will produce about 120% more low end torque. However, top speed does not increase with a higher ampacity controller.

The net result is that you can haul/tow a heavier load and that you can accelerate from a standstill faster and that the cart can climb a steeper hill without stalling the motor.

However, once the motor is spinning above the RPM at which it cannot draw more than 275A, there is little performance difference between a 275A, 500A, 600A or 2,000A controller, other than the higher ampacity controllers are less likely to overheat when worked hard.

I don't have a Torque vs RPM curve for a stock series motor, but I do have one for an aftermarket motor and the principle is the same even though the specific RPM and torque numbers are not the same.

Connected to a 48V battery pack, the unnamed motor can draw 526A and produce about 80ft/lb of torque at about 1,000RPM
Same motor connected to same battery pack can only draw 408A and produce 60ft/lb of torque at about 1,250RPM.
Same motor connected to same battery pack can only draw 291A and produce 40ft/lb of torque at about 1,575RPM.
Same motor connected to same battery pack can only draw 231A and produce 30ft/lb of torque at about 1,800RPM.

At some RPM between 1,575 and 1,800, this motor cannot draw more than 275A, so below that RPM there is a significant performance difference with a higher amp controller and above that RPM, there isn't.

FWIW: The motor in the example has over 15HP (About 11.5 @36V) while a stock series motor is only about 2.5HP.

Since this motor can draw over 500A at low RPM, a 600A or larger controller is needed to obtain maximum performance from it. A 500A controller is about all a stock series motor can handle and about 450A is max for a PDS motor.

Based on this, I don't think the 2 gauge cables will have any effect on top speed. Since the motor isn't pulling as many amps at top speed, the 6 gauge wires should be sufficient for top speed evaluations.

[ticklechicken]

Originally Posted by TahoeDawgZ71

I recommend a higher amp controller, heavy duty solenoid, and heavy gauge cables to get your torque back.

Thanks. The cables are on their way here.

Regarding controller, solenoid, and motors - which is the most bang for your buck to get a torque increase?

[TahoeDawgZ71]

Originally Posted by ticklechicken

Thanks. The cables are on their way here.

Regarding controller, solenoid, and motors - which is the most bang for your buck to get a torque increase?

There are lots of different options for controllers. Give me a ring if you want to talk about options. Phone number is on web site. Link below.

[ticklechicken]

UPDATE - Upgrading the 6 gauge wires to 2 gauge increased the speed almost 1mph. I was surprised at that. Low speed torque was noticeably improved too. Next, I increased the front/rear tire pressures from 5/7 to 7/9 psi. This added about 1/2 mph.

[mrgolf]

Originally Posted by ticklechicken

UPDATE - Upgrading the 6 gauge wires to 2 gauge increased the speed almost 1mph. I was surprised at that. Low speed torque was noticeably improved too. Next, I increased the front/rear tire pressures from 5/7 to 7/9 psi. This added about 1/2 mph.

Yelp, you need more amps.