
How to: Make an RC Car Faster
You recently acquired your first actual remote-controlled vehicle, and you are in love with it. Since you've been operating it daily, often twice a day, you've undoubtedly improved your driving abilities. However, something begins to growl in your stomach—that never-ending thirst for power! And we're going to teach you how to satisfy that need and speed up your RC car immediately!
We'll be using this brushed HSP Viper today, but you can convert almost any brushed RC car to brushless. The Viper belongs to a class of vehicles that we call "HSP 2wd cars" as a whole. In past videos and blogs, we've discussed why we enjoy them so highly, but in summary, these cost about $200 and include a brushed motor, electronic speed control, battery, charger, and remote. Although this technology is somewhat outdated, it is incredibly user-friendly. It's not too fast for novice or inexperienced drivers, but it's fast enough to be enjoyable.
However, that is no longer you; you now want to maximize your car's potential after getting to know it. The HSP Viper can travel 36 km/h right out of the box. Not too awful, but we need to move quickly.
So! What will we do to speed it up?
Let's first examine the resources at our disposal.
Before you do anything, you can quickly determine the type of motor in your car by counting the number of motor wires:
• Two wires are included in brushed motors.
• Three wires are included in the brushless.
A 6-cell nickel-metal hydride battery and a brushed motor power this Viper. To increase its speed, what will we use instead?
We could experiment with the battery voltage to reach a few kilometres per hour, using either a 7-cell NiMH battery or LiPo power. This would definitely increase the car's acceleration, but it wouldn't significantly alter our peak speed with the stock brushed motor and ESC, and it would also limit the lifespan of these electronic parts.
By altering the gearing, we could also travel a few kays more quickly. If we have a larger pinion (or a smaller spur), we will get a bit more top speed at the sacrifice of acceleration. The car will accelerate, but it won't have any more power. Therefore, it will take longer to reach its maximum speed. Dull.
To satisfy our need for speed, we demand a consistent, quick, and significant power boost! Therefore, we will be upgrading to a LiPo battery, a new motor, and an ESC in this project. I'm referring to BRUSHLESS.
In this instance, a Hobbywing Max10 60a 4000kv brushless combo is being installed. Although there are more costly and less expensive combos available, Hobbywing is well-known for its quality and performance, and we've always had positive experiences with their electronics.
3652SL: These are the dimensions of the motor can. "SL" stands for Sensor Less, and this indicates that the motor is 52 mm long and 36 mm in diameter.
4000kv: kv is a motor's constant velocity; it is not the same as kilovolt, which is a non-existent concept.
This figure represents how many revolutions per minute (rpm) a motor produces when one volt is provided while the motor is not under any load. So, a 4000kv motor with 1v input = 4000rpm, 8000rpm with a 2v input, and so on.
Consider your vehicle's weight and dimensions before choosing a powerplant. Additionally, whether it is 2WD or 4WD is crucial because powering four wheels requires more torque. Check to see if the manufacturer already sells the same model in a brushless if you're having trouble deciding what size or KV motor to acquire for your RC car. You can use the motor they install as a starting point. For instance, the Viper BL, a brushless variant of the Viper we're upgrading today, is also available. This truck has a 60A ESC and a 3652SL 3300kv motor. This indicates that the Hobbywing combination we're installing will have less torque but be faster.
It's also important to note that different motor shafts have different characteristics. The two most popular diameters are 5mm and 3.17mm, or 1/8" of an inch. Before choosing a combo, determine which one you require because you must confirm that your new motor's pinion gear will suit it.
Your ESC's required amps may vary greatly, but more is preferable. In general, the ESC's sustained current capacity is indicated by its amp rating, which in this case is 60. Faster motors consume more energy, particularly during the first acceleration of launch. Hence, this 60A ESC with a 360A burst current will function well.
Since the motor and ESC are typically already matched, getting a combo is fantastic.
Since this combination will be far more potent than the original components, your NiMH battery may find it challenging to provide you with long-term use and may overheat.
What are the meanings of all these battery-related items? Well, fast:
Consider the Mah to be the amount of fuel in the tank or runtime.
How much power and top speed is known as voltage. Your electronics will release magic smoke if you use too much electricity. Furthermore, I still don't know how to reinstall the smoke.
Although more complicated, the "C" rating facilitates throttle response. This rating defines how much current may be extracted from the battery constantly without it experiencing damage. Imagine it as a fuel pump that can supply your engine with a more significant amount of fuel; the higher the C rating, the more fuel it can provide to your large, thirsty motor! So, for this one, go as high as your budget will allow. You risk damaging both your battery and ESC if you purchase a LiPo battery with a low C rating.
Please make sure the Low Voltage protection on your selected ESC is turned on since we're going to be dropping in this NXE 5000mah 2s lipo to maximize power and run times. Check your instructions and make sure the LVC is turned on because it protects your lips from damage caused by running the LiPo battery flat. Make sure you only ever use a charger that is compatible with lipo if, like us, you're switching to lipo power. A NiMh charger cannot be used with LiPos, and attempting to do so can be extremely risky.
Let's go quickly now that we've cleared up the nerdy stuff. You'll need the following:
• The brushless motor and ESC that you have chosen.
• A suitable LiPo battery and charger: It's crucial to remember that LiPo batteries cannot be charged using the same NiMh or NiCd chargers.
• The tools we used were a 1.5mm hex and a 2.5mm hex to remove the motor and pinion gear.
• Before attaching the new ESC, wipe the surfaces with methylated spirits and a microfiber cloth.
• To organize our wire, use zip ties.
Before you do anything, you can quickly determine the type of motor in your car by counting the number of motor wires:
• Two wires are included in brushed motors.
• Three wires are included in the brushless.
On a rear-motor 2wd chassis like this, switching from a brushed motor and ESC to a brushless motor is now quite simple and hardly noticeable. First, snap a picture of how everything was linked; you might need it later when you're adding new components.
Everything can now be unplugged, including the motor from the ESC and the ESC from the receiver (channel 2).
The ESC should now be able to be removed from the vehicle. Double-sided tape is all that holds it in place. The motor needs to be changed now.
To remove the gear cover on the Viper, unscrew two screws.
And removing the motor's bolts...Two screws.
To remove the motor from the mount, you might need to remove the pinion gear, but that's okay because we still need to transfer it to the new brushless motor.
Bolt the replacement motor in if your automobile has a fixed gear mesh. If not, tighten the motor screws while checking your mesh. Additionally, check the alignment with the spur and make any required adjustments.
Establishing the gear mesh correctly is crucial to preventing gear stripping. For additional assistance, see our video on the subject here or read the related blog.
Your new ESC can now be attached to the chassis wherever it fits best, usually using double-sided tape. When applying the double-sided tape, make sure both surfaces are spotless to ensure proper adhesion; you don't want any dust, dirt, or debris.
When you plug in your motor wires, you'll see that there are three of them; if they are labelled, they are often A, B, and C.
Connect the receiver to the ESC. It enters channel 2, where the wires typically run from left to right, signalling positive and negative. If your receiver doesn't include small markings that indicate which direction to plug it in, you might refer to the picture you took before.
Verify all of your screws, settings, and connections one more time.
We must now calibrate the ESC and transmitter to set the full throttle, neutral, brake, and reverse positions for your particular transmitter. Additionally, before beginning the calibration procedure, make sure your throttle trim is in the neutral position. For details, consult your ESC handbook; we've also produced a video that demonstrates how to calibrate ESC endpoints. You may read the blog here or watch it here.
Take a leisurely test drive to ensure everything is in working order. If you pull the trigger and the car doesn't drive forward (or moves backward), you might need to flip the radio's channel 2 reverse switch. Change any two of the motor wires and give it another go if it moves more quickly backward than forward. You should reverse the channel switch and swap two wires on some automobiles.
Before we start our first run, make sure your radio's built-in failsafe is set to the proper throttle position. If you don't, you risk a runaway!
Therefore, raise your vehicle off the ground by placing it on a box or something similar; otherwise, your runaway test could turn into a genuine one.
The remote control should typically be turned on first, followed by the vehicle. However, the car is usually turned off first, followed by the remote control.
However, we are testing the failsafe by simulating signal loss. To accomplish this, we switch off the remote control before shutting off the vehicle.
It's time to discover how much more quickly your pride and joy are now!
Our viper reached a new peak speed of 63 km/h after starting at 36 km/h! Incredible gain. Indeed, there will probably be more breaks and worn-out components. However, it's well worth it—it only provides us with a reason to tweak it for increased speed!
That's all there is to know about making your remote-controlled car quicker.