If you are anything like me, you are probably wondering what you can do to make your RC car faster. Then you complete your first modification and run the RC car for a few days. That is the point in time where you wonder can I make it go even faster. This process never gets old, it only gets more addicting! Let’s look at what you can do to increase the top speed of the average RC Car. In each case below you can use the RC Car Calculator to estimate the top speed that you can expect to see with your modification. Video Here.
No More Brushed Motors – Making Your RC Car Faster
OK, I had to get this one out of the way. If your RC car has a brushed motor, your RC Car is way too slow. Replace the brushed motor with a brushless motor. Doing this will increase the speed that you were use to seeing with your RC car drastically. To find the perfect brushless motor for your RC car, my suggestion is to start researching what others are using for that specific model. Knowing that others are using the same brushless power system is one way to make certain that you are picking a reliable, proven power system to accomplish your goals.
Change the Gear Ratio – Making Your RC Car Faster
Changing up the gear ratio on your RC car is one of the easiest things you can do to increase top speed. You have a choice between changing the motor pinion gear or the mating spur gear. The third option is that you can actually change both gears and get twice the benefit.
To increase top speed, the most common place to start is with the pinion gear. The goal is to decrease the overall gear ratio. For every turn the motor completes, we require an increase in turns that the wheels have to make. To decrease the gear ratio, we must increase the number of teeth on the Pinion Gear. To decrease the gear ratio by changing the spur gear, we would decrease the tooth count of the spur gear.
If you were to only increase, for example, the size of the pinion gear, you would eventually hit a diameter issue. There is only so much room that your RC Car will allow adjustment for. In this case you must decrease the size of the spur gear in order to make room to increase the pinion gear size. Changing both the spur gear and the pinion gear together can make a big difference in terms of the speed potential.
Increase the Cell Count – Making Your RC Car Faster
Increasing the LiPo cell count is another way that you may increase the top speed of the RC car. If your car is running on a 2 cell LiPo, moving up to a 3 cell LiPo will increase the speed significantly. In theory increasing cell count from 2 to 3 will increase speed by approximately 50%. This simple modification can make the biggest difference with the least amount of changes required. However, increasing the cell count is not always possible depending on the power system of your RC Car.
You must only do this if you know that your ESC can handle the additional voltage and amperage. The amount of current consumed by the motor is directly related to the amount of load it must overcome. Increasing the cell count, increases the expected amount of total RPM of the motor. More RPM translates in to more load. An increase in load on the ESC could destroy your ESC (and more) if it was not designed for it. Check those specs!
Increase the Motor Kv – Making Your RC Car Faster
This may be the most complex type of modification in order to squeeze more speed out of your RC car. Increasing the motor Kv essentially is an ask to swap the brushless motor for a different brushless motor that is wound with a higher Kv.
If your current setup before modifications was pushing the motor very hard, moving up to a larger motor will help. You will know if the motor was pushed very hard depending on the temperature that it reached. The next step is to find an appropriate sized motor with a higher kv value. Here again, it is best to hop on a forum and find out what someone else has been running in order to be certain the setup that you choose will remain reliable. Increasing kv is a great way to increase the speed of your rc car. Just make certain that you understand the setup well and it’s ability to maintain reliability.
Change Tire Diameter – Making Your RC Car Faster
Changing your tires on the RC car is yet another way that you can gain speed. When we are trying to increase the speed of our RC car, every little bit makes a difference to add up to the new top speed. In order to increase speed with a tire change, you must look at the diameter. Note what the diameter of the tire is on your RC car. Increasing the diameter of the tire is increasing the amount the rollout of a tire. Rollout is essentially the tire circumference. If the motor rotates the wheel 1 turn, the car will travel further when the circumference of the tire is increased. The RC Car Calculator can also help you out in determining the difference between your tire diameter selections.
How to maintain a reliable power system
It’s fun and all modifying our RC cars until the unthinkable happens. That’s when one of the components of your power system decides to just say NO to your modification. You will know it’s too late when that component is smoldering with smoke pouring out of your RC Car. Demanding more power from your power system is what you are doing when trying to achieve a higher top speed. More power mean more heat to the electrical components. Pushing them too hard and they will overheat and ignite.
To prevent this rather unfortunate situation, make certain to monitor the temperature of the motor, ESC, and batteries. I would recommend not exceeding 60C or 140F in temperature for the motor and batteries. My recommendation for the ESC is 70C or 160F. Refer to the owners manual of the particular ESC for exact specifics. Being certain that you are not overheating the components will reduce your risk.