RXV Curtis programming and top speeds

[racemrc]

I am new to the forum and have read many posts relative to speed enhancements for the RXV. I am trying to plan a build and would like to know if anyone has this info. I see CGTech has been able to work around the programming in the controller, how do I contact him or anyone else that has done this? I am not able to PM yet.

My question is, what is the maximum motor speed I can expect from the controller? It looks like 6,250 RPMs with freedom on and set by handheld to 19.6 MPH. What can you get it to spin with other programming methods? I was considering using the 350amp optional ezgo controller, but I assume the same limitations apply? Is there further benefit to using another controller for the stock motor, but losing the motor braking feature? I will be adding hydraulic front brakes either way. Is it possible to add the rear drums from a gas cart to the electric RXV rear end?

[Dramier]

I will leave the speed questions to those who have experimented with the RXV.

The rear of the electric RXV has a different axle setup than TXT's or GAS RXV's. The axles on most gas vehicles are a larger diameter than the electrics. If I'm not mistaken this is the case with the RXV. The rear axle of the electric RXV also does not have the mounting flanges on the end of the axles for the brake drum setup to mount on at all.

You also don't have the correct pedal assembly on the brake pedal itself to allow attaching the brake drum cables to it. All in all I would tend to think doing the conversion would be quite a bit of fabrication unless there's already an existing kit available, which somebody here might know of one.

[mjroman20]

http://www.buggiesgonewild.com/elect...rxv-speed.html

No programming will take it past the factory freedom speed. Hardware change is required from there on out. EZGO has that locked down tight. same deal with the 350A.

Depending on your technical level or willingness to pay out the wazoo for something to be developed I'd say try a Curtis 1236. It can be tuned to pretty much any AC motor, but it would require some re-wring of the vehicle harness.

[Dramier]

One thing you may not have considered...

You could go to a 14" rim with low profile tire and/or change out the rear differential gears to a better ratio. I've heard of shops claiming some pretty ludicrous speeds, but there are drawbacks such as loss of torque, etc, depending on what ratio you go with. I've done gears in TXT's as fast as 50mph, but have never touched an RXV.

[Isaac-1]

Keep in mind that I am sort of thinking outloud here, but it seems like the controller in the RXV limit is set by input from the rate of rotation of the motor, and it get this information from the shaft encoder, so simply changing out the quadrature shaft encoder for one with half as many counts per revolution would double the governed top speed. Of course it may also through off acceleration curves, etc. if the controller is designed to ramp up and ramp down such things.

[cgtech]

funny you mention that... i tried modifying on a yamaha AC motor (same motor manufacturer as RXV motor, higher HP model). while that was a Toyota motor controller, not Curtis or Danaher, it did not work at all. the controller knew this was BS and was pissed, it actually decreased speed to about 4mph.

[mjroman20]

Yes, I wouldn't mess with the encoder counts... AC motors and controllers are very picky. If the encoder signal is wrong, as in wrong expected count, phase shift, etc then one of two things happens. The system simply stops or the control pushes a s#!+ ton of current to try and correct what it thinks is a runaway motor and then shuts down.