How can I get more speed from my golf cart? If I only had a nickel for every time this question was posed towards our company. Golf cars have been around in one form or another for more than 60 years. Back then, they were the new necessity for courses as a money maker, to aid the speed of play, and make golfer’s lives easier. A lot has changed since then, and golf cars and all of the various tangents thereof, have developed into the multi-purpose utilitarian vehicle of today and the future.
The vast majority of golf car owners are no longer golfers.
Most are now used for a wide range of non-golf related uses such as hunting, camping, racing, farming, industrial, campuses, and much more. As the function of the vehicle has changed, so have the specific needs of that vehicle. Instead of merely needing to get one round of golf on a charge, now vehicles have to travel long distances in many large scale communities, gated or otherwise. With the increase in distance comes the need to cover that distance more quickly and efficiently and has led rise to our topic, “How To Make Your Golf Car Faster”. This topic has enough fuel for a full scale collegiate text book, but for the purpose of this discussion, I will be limiting it to the basic fundamental principles only.
Let’s discuss the specifics of how to make your golf car faster. So, what are your options?
• Change the gear ratio.
- Most stock golf cars have a standard gear ratio in the differential of approximately 12.5:1, which means for every 12.5 revolutions of the input shaft (where the clutch mounts on a gas car and the motor on an electric), the wheels will spin one complete rotation. If you drop the gear ratio to 6:1 for example, now the wheels turn one time for every 6 times the input shaft turns, making the golf car go faster. Usually, all else being equal (tire size, rpm, voltage, etc.), changing the gear ratio from 12.5:1 down to 6:1, will gain you another 12-14 mph.
- This upgrade is not without a cost. Your transmission is not shiftable in a golf car, like a manual transmission in an automobile. You are permanently in a higher gear. What happens when you are in fourth gear in your car? You have a higher top end speed, but you have no low end torque. The same is true in your golf car. Changing the ratio will result in higher speeds, but will sacrifice torque to do so. If you are in a flat area this may not be noticeable. However, if you are in a hilly area, carry heavy loads, or have a lifted car with larger tires, the loss of torque may be too great for the car to function as needed. Be sure to consider the consequences carefully prior to changing any gear ratios.
• Increase the rpms.
- Increasing the rpm of your vehicle’s power plant is another way to get more top end speed out of your vehicle. This is achieved in different manners on gas versus electric cars, but the principle is the same. If you
increase the rpm of the input shaft for any differential, regardless of the
ratio inside, the output will be faster.
- On a gas golf car, there are two ways to increase the rpm. The first would
be to adjust the governor. Typically, an easy adjustment to a mechanical ground speed governor assembly is all that is needed. Some golf cars have a secondary electronic governor to prevent excessive and possibly damaging rpm levels. These are much harder to adjust and/or bypass. The other option would be to completely change out the engine, with another capable of higher rpm output. This is typically fairly involved and costly, but can produce great results.
- On an electric golf car, you have several options to achieve a higher rpm
for greater speed. The first option is to change out the electric motor. Most
electric motors are designed for either speed or torque. Torque motors have a large field coil inside producing a strong magnetic field to exert greater force on the armature for torque. These motors typically produce lots of torque but lower speeds. Speed motors, on the other hand, have a much smaller field coil and produce a much weaker magnetic field. This field weakening allows for the armature to spin faster. Install a motor rated at higher rpm and your top speed will increase. Worth noting on this upgrade is that although a “speed” motor will increase your speed, it will also decrease your torque which we discussed above.
- The second option to increase the rpm on an electric golf car would be to
increase the voltage. In simplest electrical terms, amperage (or current) equals torque, and voltage will equal speed. Just increase the voltage to
the existing motor, and it will spin faster. Many motors are rated for a range of voltages. For our purposes, the common models are 24-36 VDC or 36-48 VDC. If you take a motor rated for 36-48 VDC, which is currently running on 36 VDC and now power it with 48 VDC, it will cause the rpm output to be much higher, thus increasing your speed.
• Increase the tire size.
- Increasing the tire size is one of the easiest and most economical ways to get a little more speed out of your golf car. This applies equally to both gas and electric golf cars. If you install a larger diameter tire on your golf car, then end result is a higher top end speed. Again, this upgrade, like the others before it, is not without a down side. Although the larger tires will result in higher speeds they, too will detract from your low end torque because now it takes more power to turn the larger tire than the smaller version. On electric golf car, you may find the need to later upgrade your electronic speed controller and other components to recover some of this lost torque depending on your application or terrain. On a gas golf car, you may need clutch upgrades to recover the lost torque.
Simple Golf Car Speed Calculator
Speed (mph) = (rpm of motor x radius of tire) / (gear ratio x 168)
12.5: 1 (Stock) Gear Ratio
12.857 mph = (3000 x 9) / (12.5 x 168) = (27,000 / 2,100)
6.0:1 (Highest Speed) Gear Ratio
26.786 mph = (3000 x 9) / (6 x 168) = (27,000 / 1,008)
The discussion above barely scratches the surface on the details of each option to make your golf car faster. Check back with (www.golfcarcatalog.com) for further technical articles and more specific details of each topic in the future.
Product Development Director, www.golfcarcatalog.com