How to Make Your CO2 Car Go Faster

To make a CO2 dragster faster: streamline the body to cut aerodynamic drag, reduce wheel and axle friction, minimize mass within the rules, ensure perfectly straight tracking, and deliver clean, leak-free thrust from the cartridge—while following safety and competition guidelines. Below, we unpack each factor with practical steps you can apply before race day.

Know the Rules and Keep Safety First

Every competition—whether classroom, regional, or national—has specifications on dimensions, mass, axle placement, eyelet location, cartridge seating, and materials. Performance gains only count if your car passes inspection, and CO2 cartridges require careful handling.

This list outlines essential safety and compliance practices that protect you and your project while preserving fairness.

• Read the official rulebook first and design to the minimums: length, width, body cross-section, minimum mass, wheel size, and cartridge hole dimensions.
• Never modify, heat, or puncture CO2 cartridges yourself. Use the approved launcher only and store cartridges at room temperature, out of direct sun.
• Respect restricted features (e.g., enclosed wheels, bearings, body cavities) if your rules prohibit them; many competitions specify allowed bushings and wheel materials.
• Leave sufficient material around the cartridge chamber and axle holes to maintain structural integrity under launch loads.
• Document your build and measurements so you can quickly pass inspection and make last-minute adjustments if needed.

Adhering to rules and safety guidelines avoids disqualifications and accidents while giving you a stable platform to chase speed.

Reduce Aerodynamic Drag

At race speeds, air resistance is often the dominant force slowing a CO2 car. Your goal is to reduce frontal area and create a body that lets air reattach smoothly behind the car, minimizing turbulence. Small finishing details can translate into big time savings over a short track.

Use the following aerodynamic principles to shape and finish your body wisely.

• Keep the frontal area as small as rules allow; use a narrow, low profile that still meets minimum cross-section requirements.
• Adopt a streamlined, teardrop-like body: a rounded leading edge and a gradually tapering tail reduce pressure drag.
• Blend transitions: use gentle fillets where the body meets wheel supports, eyelets, and the cartridge housing to limit flow separation.
• Fair the wheels if permitted: use thin, rigid wheels; shield or partially recess them only if rules allow. Otherwise, reduce the exposed wheel face and spoke turbulence.
• Finish smooth: sand progressively (e.g., 220 → 400 → 800 grit), then apply a thin, even paint and a light polish. Avoid thick coats that add weight and roughness.
• Keep external features aligned with the airflow. Misaligned eyelets, decals, or protrusions can trip turbulence.

Balancing sleek shaping with structural needs gives you lower drag without compromising strength or legality.

Minimize Rolling Resistance and Friction

Energy lost to wheel and axle friction never returns. Precision and cleanliness matter: trueness of wheels, alignment of axles, and the right lubrication can shave crucial milliseconds.

These steps target the largest sources of rolling losses.

• True the wheels: ensure rims are round and flat, with minimal wobble. Replace warped or out-of-round wheels.
• Polish the axles to a mirror finish to reduce microscopic abrasion; avoid grooves that collect debris.
• Use dry lubricants (e.g., graphite) if allowed; avoid oils that attract dust and thicken.
• Align axles perfectly square to the body using a jig; even minor toe-in/out or camber induces scrub and speed loss.
• Minimize contact points: use low-friction bushings or inserts if permitted, and ensure the axle only touches at intentional bearing surfaces.
• Keep the rolling path clean: remove paint overspray from bores and wheel hubs; ensure no rubbing against the body.

Low-friction rolling components maintain speed from launch to finish, especially when alignment keeps the car from scrubbing against the guide system.

Optimize Mass and Balance

Lighter cars accelerate faster under the same thrust, but they must remain stiff and rule-compliant. Strategic material removal and smart mass placement improve both speed and stability.

Apply these techniques to approach the minimum allowed mass without sacrificing strength.

• Hollow strategically: core out non-critical interior regions while maintaining robust walls around the cartridge, axles, and guide eyelets.
• Keep mass low and central along the longitudinal axis to reduce pitching and yawing during launch and runout.
• Aim for symmetry left-to-right to help it track straight; imbalance introduces drift and drag.
• Stay just above the minimum mass to account for paint and hardware. Weigh frequently with a precise scale during the build.

Prioritizing a light yet rigid body provides quicker acceleration and more predictable handling on the guide line.

Maximize Thrust Transfer

The CO2 cartridge provides a powerful but brief burst. Your job is to seat it correctly, minimize leakage, and avoid any obstructions that waste pressure or create chaotic flow at the exit.

Consider the following best practices to preserve as much thrust as possible.

• Maintain a precise, smooth cartridge chamber: no paint, glue, or fibers near the seal; remove burrs so the launcher’s seal mates cleanly.
• Ensure accurate alignment so the launcher pin punctures straight and fully; misalignment can cause partial piercing or leakage.
• Avoid extra dead volume behind the cartridge; follow the specified bore dimensions so expanding gas exits efficiently.
• Inspect and clean the rear opening and seat before runs; any debris can disrupt the seal and reduce initial thrust.
• Do not modify the cartridge or launcher; rely on preparation and fitment to improve consistency.

Clean interfaces and precise geometry help convert cartridge pressure into forward motion rather than wasted leaks or turbulence.

Keep It Straight and Stable

CO2 dragsters typically run on a guide line or track system. If the car oscillates, scrubs, or rubs, it burns speed. Accuracy in geometry and smooth interfaces with the guide system are vital.

Use these checks to ensure it holds a straight, low-drag path.

• Square the axles with a reliable jig, then verify with a straightedge and feeler gauges across the wheelbase.
• Align and deburr guide eyelets; ensure they are coaxial and smooth so the line slides freely.
• Balance wheels to reduce vibration; even small imbalances can induce sideways loads.
• Confirm ground clearance is even and wheels do not contact the body under load.
• Conduct roll tests on a flat surface: the car should track straight without correction.

Stability reduces parasitic losses and prevents small misalignments from compounding into major time penalties.

Test, Measure, Iterate

Fast CO2 cars are refined through evidence, not guesswork. Short sprints, data logging, and controlled comparisons let you isolate what truly helps.

Follow these habits to make each change count.

• Use consistent test conditions (same lane, surface, cartridges at room temperature). Never heat cartridges to “gain pressure.”
• Time runs with gates or high-frame-rate video; record changes one variable at a time.
• Log mass, wheel prep, lubrication method, and alignment notes; correlate with run times.
• Inspect after each run for rubbing, loosening parts, or surface damage; fix immediately.
• Create a pre-race checklist: wheel spin test, axle alignment check, eyelet smoothness, cartridge chamber clean, weight verification.

Iterative testing turns good designs into winning ones by validating improvements and eliminating placebo effects.

Common Mistakes to Avoid

Many promising cars slow down due to avoidable pitfalls. Keep these in mind as you plan and build.

Here are frequent issues that undermine performance and how to sidestep them.

• Over-sanding or hollowing that weakens the body near the cartridge or axles.
• Thick, uneven paint that adds weight and surface roughness.
• Wet lubricants that gather dust and increase drag over time.
• Misaligned axle holes drilled by hand without a jig, causing scrub.
• Ignoring rule tolerances and failing inspection, forcing last-minute, speed-killing fixes.

Avoiding these traps preserves your time and performance, letting you focus on fine-tuning.

Summary

Speed in a CO2 car comes from mastering fundamentals: low drag, low friction, minimal but strong mass, straight tracking, and efficient thrust transfer—all inside the rulebook and with strict safety. Shape a sleek, rigid body; perfect your wheels, axles, and alignment; seat the cartridge cleanly; and validate every change with disciplined testing. Do that, and you’ll give your car the best shot at the podium.

How to make a CO2 car faster?

Simply put, the less weight your dragster has, the faster it will go. This is the most important factor that will figure into your design. Keep it light! Thrust: The gas escaping from the CO2 cartridge in the car.

How fast do CO2 cars go?

CO2 dragsters can reach speeds from around 35 to 70 miles per hour (56 to 113 km/h), with some reaching up to 79 km/h (49 mph) or even faster depending on the specific competition. These lightweight, CO2-powered cars are propelled by a compressed CO2 cartridge down a flat, level track and can cross a 20-meter (65.5-foot) track in just over a second. 
Factors influencing speed

• Weight: Opens in new tabThe lighter the car, the faster it will go, making mass a crucial design factor, according to HowStuffWorks. 
• Aerodynamics: Opens in new tabThe cars’ design, particularly a rounded front and tapered rear, helps reduce wind resistance and improve speed. 
• Track Length: Opens in new tabThe cars are designed to operate on a standard 20-meter track, which helps dictate their typical speed range. 

Common speeds

• Typical Speeds: Many CO2 dragsters can reach speeds in the range of 35 to 40 mph. 
• Higher End: Some high-performing cars can achieve speeds of 60 to 70 mph or even more. 
• Record Speeds: During one competition, a dragster was clocked at a speed of 68 mph. 

What makes a CO2 dragster go faster?

A CO2 dragster’s speed comes from its lightweight design, an aerodynamic body to minimize air resistance, and an efficient CO2 cartridge system to provide maximum thrust. Minimizing the car’s mass increases acceleration, while a smooth, tapered body reduces aerodynamic drag. The CO2 power plant and the design of its valve system are crucial for releasing gas efficiently, and proper alignment of wheels and axles reduces friction and improves rolling performance.
 
You can watch this video to learn more about the design of CO2 dragsters: 55sPitsco EducationYouTube · Mar 4, 2020
Key factors for speed:

• Lightweight design: Reducing mass is a primary factor, as a lighter car requires less energy to accelerate and will thus go faster. 
• Aerodynamics: A sleek, streamlined, and tapered body shape, resembling a teardrop, helps the car cut through the air more efficiently, reducing drag and increasing speed. 
• Efficient CO2 power plant: The CO2 cartridge and valve system are responsible for the thrust. A well-designed valve ensures the efficient and rapid release of the compressed gas. 
• Low friction: The wheels, axles, and chassis must be designed to minimize rolling resistance and other forms of friction to allow the car to glide smoothly down the track. 
• Proper alignment: The wheels and axles must be perfectly aligned to avoid creating additional drag or friction that would slow the car down. 
• Efficient use of gas: The design of the nozzle and the valve’s timing are critical for how quickly and efficiently the CO2 gas expands, maximizing the forward propulsion. 
• Material choice: Using lightweight materials for the body, such as balsa wood or plastic, contributes to a lower overall mass. 

This video demonstrates how to improve the aerodynamics of a CO2 dragster: 55sTimothy LeMoineYouTube · Oct 30, 2018

What factors will affect the CO2 car speed?

Design factors include minimizing weight, optimizing aerodynamics, and efficient CO2 energy use. The materials used for the body and chassis are crucial for performance and durability. The CO2 cartridge and valve system are key components in determining acceleration and speed.