If you’re into RC odds are you have the proverbial need for speed we all seem to have. Whether you race or bash, going fast is fun. And, unlike full-size, there aren’t the same consequences–no speeding tickets and usually no physical harm to people. Sure, you can hurt yourself or someone else, so caution should be taken and good judgement should be used, and you can wreck your RC, but it is definitely a lot easier on the wallet and body to crash at 65 mph with an RC than it is in a real car. So, all of that are a big reason why we like speed so much with RC. We can get away with things we normally couldn’t. There’s the thrill without the danger. That’s all great, and in the immortal words of Ricky Bobby, “I wanna go fast,” but how do you go fast? Below are the top five proven ways to make any electric RC car or truck faster.
Making a gearing change is probably the easiest and least expensive way to get more speed. The two gears that are typically adjustable are the pinion (attached to the motor) and the spur. Installing a larger pinion will make your vehicle faster. Installing a smaller spur gear will do the same. All at the expensive of acceleration and runtime. You also run the risk of overheating your motor, speed control and even battery is you use too large of a pinion or too small of a spur gear. Also, keep in mind that the pinion, in addition to being easier to change, also makes a bigger difference, tooth for tooth, compared to the spur gear. Point is you’ll notice a two-tooth change on a pinion, but probably wouldn’t notice the same change on a spur gear.
More voltage equals more speed. In fact, more voltage might be one of the best ways to significantly increase performance because more voltage increases acceleration and top speed. Voltage, of course, all comes from your battery. If you’re running a 2S (two cell) LiPo, go to 3S. You can go to 4S for an even bigger speed increase. What you can get away with all depends of your current speed control and motor. Do not exceed their rated levels. If your speed control (aka ESC) is rated for a maximum of 2S or 7.4 volts, you will need to upgrade in order to go to 3S or more.
Going up in voltage isn’t always the answer. Neil Cragg won a 2WD world championship running a 5-cell NiMH pack instead of the allowed 6-cell pack. This was back in the day before LiPos.
The main way tires can make your truck faster is via size. Taller tires work like a gearing change with the same impact. Taller tires will increase top speed at the expense of acceleration and runtime. Small changes aren’t likely to be noticed. Lighter tires, however, can increase acceleration and improve runtime. Lighter tires, however, will not improve top speed.
While attending an IFMAR World Championship at a track with extremely low traction, I asked World champion Mark Pavidis, who worked at tire giant Pro-Line Racing at the time, what tire and compound he was going to go to solve the traction problems. His answer was that once he selects a tire tread pattern and compound, he rarely changes. When traction is low, he changes gearing. He increases the pinion until the tires won’t break loose.
We all know some motors are faster than others. This is true with full-size cars and RC. But why? How do we choose a faster motor? If you’re shopping, to understand which motor should be fastest, you can compare turns or Kv. Some motors are labeled with both and some are labeled with one or the other. With turns, the fewer turns the faster the motor should be. A 12-turn motor is faster than a 21-turn motor–most of the time. Be wary of comparing RTR motors to aftermarket race-worthy motors. A RTR brushed, sealed end bell 12-turn motor with bushings is not going to be faster than 17.5 turn brushless motor. By the way, the turn rating on brushless motors are made up numbers. Brushless turn numbers are just to indicate how a motor should compare to a brushed motor. Back in the day, brushed motors were the norm and they all were rated in turns. To help consumers make sense of brushless motors, manufacturers added turn numbers to their new motors. Kv numbers work the opposite of turns. The higher the Kv rating, the faster the motor. Specifically, Kv indicates how fast the motor should spin (rpm) when a single volt is applied.
If you lose weight, you will run faster. Your RC car, however, will only benefit from increased acceleration if it loses weight. According to my high school physics teacher, mass only impacts acceleration. But, whether you’re drag racing your buddy down the street or tearing around a track on race day, your car spends more time accelerating than it does at top speed. Don’t underestimate the advantage of out accelerating your opponent. “Fast” isn’t always about top speed. Losing some weight will do some good. All of those aluminum accessories might look cool, but they hurt more than they help when it comes to performance.