Golf cart motors, controllers and speed

Speed on a golf cart is a ladder, and most owners stop two rungs up. A golf cart motor and controller are the expensive rungs; a speed code and a set of taller tires are the cheap ones, and they get a 15 mph cart to 20. Before any of it, know what you have: the make and year decide whether your top speed is set by software, by gearing or by the motor itself. The faster-cart guide walks the ladder in order; this page explains how to read your cart.

Stock speeds, and why they differ

A 1990s cart was built for a golf course and set to 12 to 15 mph. Carts built since about 2010 have a high-speed setting of 19 to 20 mph that fleets turn off and owners turn on. A low-speed vehicle, the federal class most street-legal carts register as, is built for 20 to 25 mph and the rules stop there. The LSV page covers what that class requires.

Speed codes: the free rung

Club Car IQ carts (the DS from about 2001 and the Precedent from 2004 to mid-2008) have speed codes set by a dealer with a handheld programmer, from code 1 at about 8 mph to code 4 at about 19 mph; codes 1 to 3 are a cheap change and code 4 is a paid code Club Car issues for your controller. Excel carts (Precedents from mid-2008, plus the Onward and Tempo) use the same codes. EZGO PDS carts (2000 to 2009) take a handheld setting or a plug-in speed chip that lifts the cart from about 13 mph to about 19.

Yamaha has no owner speed code on the DC carts; the G19, G22 and Drive are sepex, so top speed is held by the stock controller, and a replacement sepex controller is how you change it. The Club Car, EZGO and Yamaha fitment pages say which system each year has, and the fitment finder will tell you from the serial plate.

Series or sepex: read this before buying anything

Electric carts have one of three drive types and the parts do not cross.

Series motors have the field and armature wired in series. They pull hard from a stop and do not need the controller to know anything about the motor. Club Car DS 1995 to about 2000, EZGO TXT series carts (lever forward and reverse) and the 36V Yamaha G14 and G16 are series carts. Controllers for them are series controllers like the Alltrax SR.

Sepex, or shunt, motors have a separately excited field the controller drives on its own. They give the controller control over regen braking and top speed, which is how speed codes work. Club Car IQ and Excel, EZGO PDS, DCS and TXT48, and the Yamaha G19, G22, Drive and Drive2 DC are sepex. Controllers for them are sepex controllers like the Alltrax XCT.

AC drive uses a three-phase motor and an inverter. EZGO RXV and Yamaha Drive2 PowerTech AC are AC. Upgrades are AC kits from Navitas, sold as a controller and motor together.

A series controller on a sepex motor does nothing useful. The speed controller guide lists which controller fits which cart.

Controllers and motors

A stock controller is 250 to 300 amps. A 400-amp controller on a stock motor gives more torque on hills and a few mph on the flat, and it is the most common upgrade at about $450 to $700. Past 400 amps the stock motor overheats on long climbs, so 500 and 600-amp controllers go with a motor built for them. A matched motor and controller kit is about $1,200 to $2,000 and will take a 48V cart to 25 mph or more.

Motors come in high-speed and high-torque winds. High-speed gives top end and loses hill pull; high-torque is for lifted carts on big tires. Pick by how you drive.

Gears, tires and lithium

A high-speed gear set swaps the differential ratio from the stock 12.3:1 or so to 8:1 or 6:1 for about $400 to $700: more top speed for the same amps, less torque on hills. Taller tires do the same thing cheaper. The stock 18-inch tire to a 22-inch is about 20 percent more road per motor turn, so 15 mph becomes about 18. The lift kit guide covers what you need to clear them.

Lithium does not change top speed because voltage is the same. It does hold that voltage all day and drop 300 pounds, so the cart feels quicker and does not fade. If the pack is due anyway, the 48V lithium page is where to start; a 400-amp controller also wants a BMS rated above its peak.

Brakes first

Every rung up this ladder adds speed the brakes were not sized for. Stock drums are fine at 15 mph and marginal at 25 with two passengers. Before a motor or a gear set, adjust the drums, replace worn shoes, and look at a disc conversion over 22 mph. Seat belts from the seat belt guide are the other half of that spend.

Gas conversions

Gas carts are governed to 14 to 19 mph and the governor is adjustable within reason. Beyond that, a Vegas Carts conversion kit mounts a larger engine, commonly a Predator 670 or a Honda twin, on the stock frame for about $1,500 to $3,500 depending on the engine. The faster-cart guide covers when a conversion makes more sense than an electric upgrade.