How to increase the speed of an electric RC car?
📅 Updated and expanded on November 11, 2025
The initial thrill of driving your RC car gives way to a new desire: to go faster. Much faster. Whether you want to dominate your friends in the parking lot or simply experience the thrill of explosive acceleration, you've come to the right place. Increasing the speed of your remote-controlled car isn't magic; it's an accessible science.
This comprehensive guide will reveal, step by step, all the techniques for transforming your machine. From free tweaks to the most radical hardware upgrades, we'll cover everything with concrete figures and precise budgets. Buckle up, the clock is ticking.
⭐ Which Change Should You Prioritize? The Strategic Board
Before you begin, here's a visual guide to help you choose modifications based on your budget, goals, and technical skill level. This table ranks the improvements by actual effectiveness and return on investment.
💡 Expert strategy tip: Always start with free and inexpensive modifications (ranks 1-2). If your car is 3S compatible, this is the best performance-to-price upgrade. If it isn't, focus on gears and mechanical optimization before considering a complete motor swap.
🆓 Easy and Free Earnings: Optimization Before You Buy
Even before you take out your wallet, you can gain between 5 and 15% more speed. Speed is also a matter of physics: the less friction and resistance there is, the faster you go .
🧹 Complete Cleaning and Lubrication
A transmission (gears, differentials, wheel axles) clogged with dust, mud or sand creates enormous resistance that literally "steals" your power.
Optimal procedure:
- Disassemble the transmission and clean each gear with a brush and degreaser.
- Lubricate the gears with special RC silicone grease (resistant to high speeds)
- Oil the axles, universal joints and differentials with light oil (200-500 WT)
- Clean the electrical contacts (connectors, sockets) with isopropyl alcohol.
📊 Expected gain: 3-8 km/h on a heavily soiled car. On a car reaching 50 km/h, this represents a 5-10% speed recovery.
🔧 Bearing Inspection and Replacement
Seized, worn, or rusty ball bearings are invisible but devastating obstacles. They can cause you to lose up to 15% of your speed without you even realizing it.
Simple test: Lift your car and spin each wheel by hand. The rotation should be long (more than 5 seconds), free, quiet, and without any stiff spots. If not, cleaning with WD-40 or replacement is necessary.
Cost: Complete bearing set = €15-25. For more details on preventative maintenance, please refer to our complete maintenance guide .
⚙️ Method #1: Changing the Transmission Ratio (Sprocket / Crown)
This is the simplest, cheapest, and one of the most effective ways to improve your car's speed. For €5-15 and 10 minutes of work, you can gain 10-20 km/h.
📐 Understanding the Principle of the Transmission Ratio
The gear ratio is the balance between the pinion gear (the small toothed wheel on the motor shaft) and the spur gear (the large main toothed wheel). Think of it like the gears on a bicycle.
📐 Report formula:
Ratio = Crown teeth ÷ Pinion teeth
A concrete example illustrated:
- Original configuration: 54-tooth sprocket / 15-tooth pinion = Ratio 3.6
- After modification: 54-tooth sprocket / 17-tooth pinion = Ratio 3.18
- ✅ Result: 12% reduction in gear ratio, resulting in approximately 12% more speed
📊 Effects Table: How to Change Your Speed
⚠️ Beware of overheating and compatibility!
Critical thermal management: Increasing the size of the motor pinion puts more strain on the motor and ESC, generating more heat. Proceed gradually (increase by 2 teeth at a time) and check the temperature after 5-10 minutes of intensive driving.
- ✅ Acceptable temperature: 60-75°C (hot to the touch but bearable for 2-3 seconds)
- ⚠️ Maximum temperature: 80-85°C (very hot, difficult to tolerate)
- 🚫 Dangerous temperature: >90°C (risk of permanent damage, return to the previous gear)
Essential mechanical compatibility: Check that your new pinion has the same module (not the number of teeth, usually 0.8 or 1.0 for 1/10 scales) and the same bore diameter (2.3mm, 3.175mm, or 5mm depending on the motor). The gap between the pinion and crown gear should allow a sheet of paper to pass through: not too tight (rapid wear) nor too loose (noise and skipping teeth).
🛒 Where to find it: Explore our range of sprockets and spare parts to find the perfect ratio for your setup.
🔋 Method #2: Increase the Battery Voltage (Switch to 3S, 4S...)
This is the most spectacular and impressive improvement. The speed of a brushless electric motor is directly proportional to the voltage (in volts) applied to it. This is an immutable physical law.
⚡ Understanding the Cell System (S)
In the RC world, voltage is indicated by the number of cells in the Li-Po battery, abbreviated as "S". Each Li-Po cell provides a nominal voltage of 3.7V (4.2V fully charged).
🔋 2S Battery
2 × 3.7V = 7.4V
Standard 1/10 leisure
🔋🔋 3S Battery
3 × 3.7V = 11.1V
High performance
🔋🔋🔋 4S Battery
4 × 3.7V = 14.8V
Competition/Speed
📊 Real Impact on Speed: Concrete, Quantified Examples
🚀 Scenario 1: Transition from 2S to 3S
- Voltage increase: +50% (7.4V → 11.1V)
- Original speed in 2S mode: 45 km/h
- Expected speed in 3S: 67-70 km/h (+50%)
- Cost: €35-60 (quality 3S battery)
🚀🚀 Scenario 2: Transition from 3S to 4S
- Voltage increase: +33% (11.1V → 14.8V)
- Original speed in 3S mode: 70 km/h
- Expected speed in 4S: 93-95 km/h (+33%)
- Cost: €50-90 (4S battery + ESC if necessary)
🚨 Crucial Compatibility and Safety Warning 🚨
You can only use a higher voltage battery if your system is explicitly compatible. Three components must be able to support the new voltage:
- The ESC (electronic controller): Check the specifications. A "2-3S" ESC can handle 2S or 3S batteries. A "2S only" ESC will be instantly destroyed by a 3S battery.
- The motor: Brushless motors generally support a range of voltages, but check the maximum amperage specifications.
- The steering servo and receiver: If your ESC doesn't have a BEC (power circuit) that regulates the voltage for the servo, a 3S or 4S battery can fry the servo. Most modern ESCs have a 5-6V BEC, but check.
⚡ Amperage and heat dissipation: Higher voltage increases current consumption. An ESC rated for 60A on a 2S battery can exceed 90A on a 3S battery. Make sure your ESC has a safety margin (at least 20-30% above the actual current draw).
📖 To learn more: Consult our complete guide on Li-Po batteries to find out everything about safety and the optimal choice.
⚖️ Impact on Range: The Speed/Duration Trade-off
More voltage = more speed, but also less range . A car traveling at 70 km/h instead of 45 km/h consumes more energy per minute of driving.
🔋 In 2S (45 km/h)
20-25 min
with 5000mAh battery
🔋🔋 In 3S (70 km/h)
12-18 min
with the same capacity
💡 Solution: Buy a higher capacity battery (6000-8000 mAh) to compensate for the increased consumption and maintain comfortable battery life.
🏎️ Method #3: Install a Higher Performance Brushless Motor (KV)
If you already have a brushless motor but want even more speed without changing the battery, you can upgrade to a motor with a higher KV .
⚡ Understanding KV: The Key to Speed
The KV (revolutions per minute per volt) indicates the number of revolutions the motor will make for each volt applied. It's the performance DNA of your motor.
📐 Formula for Calculating Theoretical Speed
Motor RPM = KV × Battery voltage (V)
Calculated practical examples:
- 3000 KV + 2S (7.4V) motor: 3000 × 7.4 = 22,200 RPM
- 4500 KV + 2S (7.4V) motor: 4500 × 7.4 = 33,300 RPM
- Expected speed gain: +50% in rotational speed = approximately +40-45% in actual speed (after mechanical losses)
🎯 Choose the Right KV for Your Use
🐢 Low KV (1800-2500)
Usage: Crawling, heavy monster trucks, scale vehicles
Features: High torque, strong acceleration, moderate speed
⚖️ Average KV (2500-3500)
Use: Versatile all-terrain vehicle (bashing)
Features: Best compromise between acceleration and speed
🚀 High KV (3500-5000)
Use: Racing buggies, speed runs
Features: Maximum top speed, reduced torque
🔥 Very High KV (5000+)
Use: Ultra-light cars, pure speed
Features: Requires cooling and reinforced transmission
⚡ Important: High KV = More Heat and Less Torque
A motor with a high KV rating spins faster but delivers less torque at low RPM. Consequences to anticipate:
- ⚠️ Slower acceleration since stopping
- 🌡️ Overheats more quickly (the motor is under greater strain)
- ⚙️ Increased wear on the transmission and gears
- 🌀 Often requires a motor cooling fan (€10-20)
💰 Typical cost: Quality brushless motor = €40-100 depending on the brand and performance. 📖 To make the right technical choice, our guide to brushless technology is essential.
🎯 Method #4: Fine-tuning Advanced Settings (Weight, Tires, Aerodynamics)
Once the raw power is optimized, the quest for those last few km/h comes down to the details. These modifications may seem minor, but combined, they represent a cumulative speed gain of 5-12% .
🏋️ Weight Reduction: Every Gram Counts
Physics is unforgiving: the less mass there is to move, the faster the acceleration and the easier it is to reach top speed.
⚖️ Effective Weight Loss Techniques
| Modification | Weight Gain | Cost |
|---|---|---|
| Removal of non-essential accessories | -50 to -150g | Free |
| Aluminium/titanium screw | -30 to -80g | 20-40€ |
| Carbon fiber parts (baseboard, arm) | -80 to -200g | 40-120€ |
| Bodywork removal (speed runs) | -100 to -250g | Free |
📊 Actual measured impact: Each 100g reduction results in approximately a 2-3% gain in acceleration and a 1-2% gain in top speed on a 1.5-2 kg car.
⚠️ Safety warning: NEVER remove essential protective elements (front/rear bumpers, chassis protection) or structural components. Safety always takes precedence over saving those last few grams.
🛞 Tire Optimization: Grip vs. Speed
The type of tire has a direct and measurable impact on top speed, handling, and energy consumption.
🏁 Tire Selection Guide for Speed
For speed runs on tarmac/asphalt:
-
Slick tires (slicks): Maximum contact patch, minimum rolling resistance, ideal for pure speed on flat, dry surfaces
Examples: GRP S7, Proline Prime, Sweep Racing EXP -
Low-profile "street" tires: A compromise between grip and speed, shallow profile reduces deformation at high speeds
Examples: HPI Phaltline, Proline Street Fighter, Kyosho EZ Series - Hard rubber: Lasts longer, less resistance, perfect for repeated runs
For fast off-road use:
-
Short "pin spike" tires: Short, widely spaced studs offer sufficient grip with less rolling resistance
Examples: Proline Holeshot, JConcepts Bar Codes, AKA Cityblock - Optimal width: Not too wide (increases resistance), not too narrow (loss of grip)
📊 "Ballooning" phenomenon: At very high speeds (70+ km/h), soft tires deform and inflate under centrifugal force, reducing grip and speed. Solutions: hard compound tires, internal reinforcement strips, or rims with anti-ballooning rings.
💰 Cost: Set of performance tires = €15-40 depending on the brand and technology.
✈️ Aerodynamics: Taming the Wind
Above 50 km/h, aerodynamic drag becomes a major limiting factor. Every improvement counts when trying to break through speed plateaus.
🌀 Aerodynamic Optimization Techniques
- Streamlined body: Choose a low, streamlined body with no sharp edges. Avoid tall and wide "monster truck" shapes for speed runs.
- Rear wing adjustment: A properly adjusted wing (10-15° angle) creates downforce that keeps the car planted at high speed, preventing spins and loss of control. Too much angle = too much drag = loss of speed.
- Lowering the center of gravity: Set the suspension to the lowest position (minimum ground clearance of 10-15mm). The car will be more stable and will cut through the wind better.
- Sealing openings: Fill unnecessary holes and openings in the bodywork with lightweight adhesive tape to reduce aerodynamic drag.
- Battery position: Center and lower the battery as much as possible to optimize the center of gravity and aerodynamic balance.
📊 Real measured impact: A well-profiled body and an optimized spoiler can gain 3-8 km/h in top speed and significantly improve directional stability above 60 km/h.
⚡ Your Action Plan in 30 Seconds
Short on time? Here's a super-quick summary based on your budget:
💚 Budget €0
- Transmission cleaning
- Gear lubrication
- Bearing check
Expected gain: +5-10%
🧡 Budget €20
- Step 0€
- +2 tooth motor pinion
- New bearings
Expected gain: +15-25%
💙 Budget €50+
- Step 20€
- 3S battery (if compatible)
- Performance tires
Expected gain: +50-70%
❓ Frequently Asked Questions (FAQ) about Speed
🎯 What is the first thing to change for more speed on a small budget (less than €20)?
Without hesitation, the pinion gear . For €5-15, you can gain 10-15% in speed (that's 5-10 km/h on a car that can reach 50 km/h). It's the best performance-to-price ratio on the RC market. Start by increasing the pinion gear by 2 teeth and test the motor temperature after 10 minutes of driving.
📋 In what order should I make the changes?
Follow this logical and safe progression:
- Cleaning/lubrication (free, 5-10% savings)
- Sprocket +2 teeth (€10, gain 10-15%)
- 3S compatibility check : If compatible → 3S battery (€40, 40-50% savings). If not compatible → Proceed to step 4.
- Weight/tire optimization (€20-60, 5-10% savings)
- High KV motor if still insufficient (€60-100, 20-30% gain)
- Combo ESC/Pro Motor as a last resort (150-250€, 50-80% gain)
Golden rule: Fully exploit each step before moving on to the next. Test, measure, adjust.
⚠️ Does increasing speed make my car more fragile?
Yes, inevitably. More speed means:
- More violent impacts: A crash at 70 km/h generates 2.4 times more energy than at 45 km/h. Regularly check the condition of the chassis, suspension arms, and shock absorber mounts.
- Accelerated wear: The transmission (gears, differentials, cardan shafts) and tires wear out more quickly.
- Thermal constraints: Motor, ESC and battery heat up more.
Preventive solutions: Upgrade to reinforced metal parts (arms, spindles, gimbals), addition of cooling fans (motor and ESC), visual inspection after each intense session.
🔌 Do I need to change my ESC if I change the motor or the battery?
This depends on three critical factors:
- Voltage compatibility: Your ESC must support the number of cells in the new battery (2S, 3S, 4S). A "2-3S" ESC accepts 2S or 3S batteries, but will be destroyed by a 4S battery.
- Maximum amperage: The ESC must handle the amperage required by the new motor. Formula: Motor amperage = Motor power (W) ÷ Battery voltage (V). Add a safety margin of at least 30%.
- Motor compatibility: Modern brushless ESCs are generally compatible with all brushless motors, but check the KV specifications and maximum supported power.
💡 Tip: If in doubt or for a major upgrade, opt for a motor/ESC combo pre-configured and tested by the manufacturer. You'll avoid incompatibilities and benefit from an optimized system.
🔋 Will my battery life decrease if I increase the speed?
Yes, systematically. Battery life decreases for two reasons:
- Increased fuel consumption: More speed = more aerodynamic and mechanical resistance = more energy consumed per second
- More aggressive driving: Abrupt acceleration and full-speed runs drain the battery more quickly.
📊 Realistic estimate:
- Original speed (45 km/h): 20-25 min with a 5000mAh battery
- After upgrade (+50% speed → 70 km/h): 12-18 min with the same battery
💡 Solutions: Buy a higher capacity battery (6000-8000 mAh) or have several charged batteries to alternate. Also, ride more smoothly when you're not aiming for top speed.
📈 How much speed can I gain in total by combining all the modifications?
Example of a realistic progression on a stock car reaching 45 km/h in 2S:
- Step 1: Cleaning + lubrication → 48 km/h (+7%)
- Step 2: Sprocket +2 teeth → 54 km/h (+12% additional)
- Step 3: Switching to 3S (if compatible) → 81 km/h (+50% on the new base)
- Step 4: Weight/tire/aero optimization → 87 km/h (+7% final)
🏆 Total gain: From 45 km/h to 87 km/h = +93% top speed with an investment of around €80-120 (if 3S compatible).
If your car is not 3S compatible, expect a maximum gain of 25-35% with other modifications (45 → 56-61 km/h).
🏁 Conclusion: Speed is a balance between power and finesse
As you've probably gathered, the quest for speed is a fascinating balancing act between raw power (engine, battery, transmission) and the finesse of fine-tuning (weight, tires, aerodynamics, thermal management). Each modification adds up to create a radically transformed machine.
🔑 The 5 Keys to Success:
- Start with free and inexpensive optimizations (cleaning, sprocket)
- Progress step by step by testing and measuring the actual gains.
- Always monitor temperatures (motor, ESC) to prevent damage
- Reinforce the stressed parts before they break.
- Accept the trade-off between speed and range, and plan for multiple batteries.
If you feel your current car has reached its structural limits or that modifications would cost more than a new one, it might be time to upgrade to a model designed from the ground up for high performance. Our ultimate guide to choosing the best remote-controlled car will point you towards the fastest and most upgradeable racing machines on the market.
🚀 Ready to Unleash the Power?
Explore our selection of high-performance brushless cars and find all the spare parts you need for your next speed upgrade!
See the Fast RC Cars 🏎️