- Mon Aug 14, 2017 3:28 pm
The torque game all comes down to how much current the motor gets.
A stock 550 motor stall current is 60A each. At 18V this is going to be 50% higher (90A). That's 180A if you're running two motors. Even considering switch & wiring resistance, when you hit the gas pedal on an otherwise-stock Dune Racer it's going to try to pull >100A. This current draw will rapidly decrease as the motor starts spinning due to back-EMF in the motor windings.
Most of the "500W" ESC components have a 25-35A limit. This means that when you push the pedal, only 15-20A can go to each motor (instead of 50+), so your off-the-line torque (and acceleration) ~40% of what you had in stock 'unlimited' form. The plus side is that also means your motors and gearboxes will never have full torque applied to them, but it means it's going to be much slower off the line (assuming you weren't just spinning the wheels in both cases).
A 1000W ESC should have a slightly higher current limit, but they usually get the 1000W by increasing voltage (to 40+) instead of current. That doesn't help you here.
Example 500W unit from Ebay (peak = 24V * 28A = 672 watts):
Rated Voltage: 24Volts
Rated power: 500 watts
Under Voltage Protection: 20V±0.5V
Usable Motor: 24V500 Watts
Example 1000W (peak = 36V * 32A = 1152W):
36V motor brushed controller
matching motor: dc brushed motor
motor brush controller for Electric bicycle & scooter
rated voltage: dc 36 v
Current limit : 32A
rated power: 1000 w
Under Voltage Protection: 31.5V
The EastCoast Powerup website does say their 1000W ESC has a 50% higher current limit than the common 500W one -- a larger differential than the two ebay units I pasted above.
If you still want the features of ESC -- variable throttle, gearbox protection, etc., then I'd recommend getting 7-series motors instead of spending money on a bigger (but only slightly faster) 1000W controller. A Mabuchi 8016 (ebay) will give you about 40-45% more torque than the stock motor and at 24V will be slightly faster than your current setup at 18V. And it will handle higher speeds better (better dissipates the heat). You can also get the Banebots motor (Mabuchi 8514), or you can get the cheapo option (Nichibo 7013F - $3/ea -- see the Motor sticky thread).
If you don't care about any of the ESC features then the simplest is just to go back to straight 18V w/o limiters.
(and yes, 24V without an ESC or some other limiter setup will just break stuff)
F-150 - 24-36V with homebrew 100A variable-speed motor controller, 4x 775 motors (NOT all-wheel-drive), and fading color
Hurricane - 24V w/50A step-down controller, Mabuchi 8514 motors
Princess Mustang - 12V w/23000 RPM 550 motor and 23T gears