1999 EZ-GO 36v.

[scottyb]

see attached flow chart

[mutt3497]

Think I’m going to go to smaller 20” tire and 350 amp controller. How much more torque does controller give?

[mutt3497]

Would Curtis 25864G05 work on my cart? Mine is the series drive.

[JohnnieB]

Originally Posted by mutt3497

Think I’m going to go to smaller 20” tire and 350 amp controller. How much more torque does controller give?

Mathematically, a 350A controller pass 27% more amps to the motor than a 275A controller and the more amps, the more torque, but the motor is not 100% efficient, so the torque gain will be less than that. (Series DC motors have an efficiency curve that typical peaks at about 80% in the mid RPM range and tapers off to about 50% at high and low RPM.)

Also, the number of amps a motor is capable of drawing decreases as RPM increases, so the torque gain will only occur at RPMs below the RPM at which the motor is capable of drawing 275A. In other words, your cart will accelerate a bit quicker off the line, but will slow down just as much going uphill.

The 350A Curtis 25864G05 is essentially a used 275A controller that has been retrofitted with MOSFETs that will pass 350A mounted on a heatsink designed for MOSFETs that pass 275A, so it is more prone to overheating that the stock unit. Tires taller than stock take more amps to turn, so overheating may be an issue.

A better choice is an Alltrax SR48300, or larger. http://www.cartsunlimited.net/alltrax-sr-series--.html

The 300A version passes a peak of 350A and the heatsink is designed for at least that many amps. In addition, an optional fan can be installed to further avoid overheating.