What are CO2 dragsters?

CO2 dragsters are small, lightweight model cars propelled by the thrust of a punctured carbon dioxide cartridge, typically raced along a guided track in classrooms and student competitions. Built to teach core engineering and physics concepts, these project-based racers accelerate rapidly—often covering about 20 meters in roughly one to two seconds—while giving students hands-on experience with design, aerodynamics, materials, and testing.

How CO2 dragsters work

A CO2 dragster stores energy in a sealed cartridge filled with pressurized carbon dioxide. At the start, a launcher punctures the cartridge, creating a high-velocity jet that pushes the car forward by Newton’s third law. The vehicle runs along a guide line (usually a monofilament thread or wire) to prevent veering, and timing gates record performance. Typical classroom runs span around 20 meters; competitive designs can complete the distance near a second, translating to average speeds of 15–25 m/s (34–56 mph) with higher peak speeds. The race outcome hinges on thrust, mass (F = ma), aerodynamic drag, rolling resistance, and alignment.

Core components and materials

Most CO2 dragsters share a common set of parts, though materials and sophistication vary widely between classrooms and elite competitions. The following list outlines the essentials you’ll encounter in typical builds and kits.

• Body: Commonly balsa or basswood for easy shaping and low mass; some programs allow 3D-printed or composite sections.
• CO2 cartridge: Usually 8-gram steel bulbs; seated in a rear chamber and punctured by the launcher.
• Launcher and timing system: A piercing pin, start gate, and photoelectric finish gates measure time accurately.
• Guide line hardware: Eyelets or guide tubes keep the car tracking straight on a monofilament line or thin wire.
• Axles, wheels, and bearings/bushings: Low-friction, true-running components minimize rolling resistance.
• Fasteners and adhesives: Epoxies, CA glues, or mechanical fixtures secure components under high acceleration.
• Finishes: Sealers, primer, and paint reduce surface roughness and can improve durability and drag.

Together, these elements convert stored gas pressure into forward motion while balancing weight, stiffness, and streamlined flow to achieve consistent, fast runs.

Design and engineering considerations

Performance depends on optimizing several interacting factors. Designers iterate through sketches, CAD models, and physical tests to refine the balance between thrust, mass, drag, and durability.

• Mass distribution: Low total mass improves acceleration, but sufficient stiffness prevents wobble and axle misalignment.
• Aerodynamics: Smooth, tapered profiles reduce pressure drag; careful rear shaping helps manage wake size.
• Cross-sectional area: Smaller frontal area generally lowers drag, within structural and rule constraints.
• Surface finish: Sealed, sanded, and painted surfaces can reduce skin friction.
• Wheel/axle friction: Polished axles, quality bushings/bearings, and minimal side scrub cut rolling losses.
• Alignment: Parallel axles and true wheels prevent energy-sapping swerve and scrub.
• Center of mass: Slightly forward-biased balance can help stability on launch.
• Manufacturing tolerances: Consistent symmetry, straight bores, and clean guide-line paths aid repeatability.

The most competitive cars achieve consistency: they minimize losses across all domains rather than relying on a single “silver bullet” improvement.

Building process

Typical build steps

While methods vary by classroom and tooling, most builds follow a structured workflow that emphasizes planning, precision, and iteration.

1. Review rules and set targets: Confirm dimensions, minimum mass, wheel specs, and safety constraints.
2. Concept and CAD: Sketch forms, test clearances, and, if available, run simple CFD or drag estimates.
3. Rough shaping: Cut the body blank and establish major contours with saws or CNC.
4. Drilling and bores: Create straight axle holes and guide-line paths with jigs for accuracy.
5. Fine shaping and sealing: Sand progressively; apply sealer to harden wood fibers.
6. Primer and paint: Use thin, even coats; wet-sand between coats for a smooth finish.
7. Assembly: Install axles, wheels, and guide hardware; verify free spin and clearance.
8. Testing and tuning: Check straightness, wheel runout, and mass; adjust alignment and finish as needed.
9. Documentation: Record times and changes to inform final revisions or competition scrutineering.

Consistent measurement—using calipers, alignment jigs, and scale—pays off in both speed and reliability on race day.

Safety essentials

Because CO2 cartridges are pressurized, safe handling and proper launch procedures are non-negotiable. The following checklist covers the basics applied in classrooms and competitions.

• Wear eye protection when handling cartridges and launching.
• Store cartridges cool and dry; keep away from heat sources and direct sun.
• Never puncture a cartridge manually; only use approved launchers.
• Keep fingers and faces clear of the nozzle line and launcher pin.
• Maintain a clear track zone; spectators should stand behind barriers or lines.
• Inspect cars for cracks, loose wheels, or damaged guide hardware before racing.
• Recycle spent steel cartridges per local guidelines.

Following these steps minimizes risk while preserving the excitement of rapid launches and close finishes.

Where they’re raced

CO2 dragsters are a mainstay of STEM classrooms worldwide and feature in organized contests. In the United States, Technology Student Association (TSA) Dragster Design challenges middle and high school students to meet detailed specs and race on a standardized track. Globally, F1 in Schools pairs CO2-powered racing with advanced CAD/CAM, wind-tunnel or CFD testing, and team branding, culminating in regional, national, and international events. Rules, dimensions, and allowed materials vary by program, so teams carefully tailor designs to the governing handbook.

Performance benchmarks

On a roughly 20-meter track, entry-level school builds often record 1.2–1.8 seconds, while top-tier cars can approach or dip below one second depending on rules and timing setup. That corresponds to average speeds around 20 m/s (about 45 mph), with peak speeds typically higher early in the run when thrust is greatest. Consistency across multiple heats—rather than a single standout time—usually determines winners.

Environmental footprint and options

Each launch expels a small amount of CO2; educators increasingly track and mitigate this footprint. The following points outline impacts and practical ways to reduce them.

• Emissions per run: An 8-gram cartridge releases about 8 g of CO2, roughly equivalent to driving a typical gasoline car about 0.02 miles (≈0.03 km).
• Recycling: Spent steel bulbs are widely recyclable; collect them after heats.
• Materials choice: Responsibly sourced wood and low-VOC finishes lower the build’s environmental impact.
• Alternatives: Some programs demonstrate compressed-air or rubber-band launchers for low-CO2 practice runs.

While the emissions per race are modest, thoughtful material choices and recycling reinforce the sustainability lessons embedded in hands-on engineering.

Common mistakes and quick tips

From workshops to championships, certain pitfalls recur. Avoiding them can deliver straightforward gains in time and reliability.

• Axle misalignment: Even slight toe-in/toe-out increases scrub; use drilling jigs and verify with square/laser.
• Under-finished surfaces: Skipping sealer or final sand leaves drag-inducing roughness.
• Loose wheels or bushes: Play creates wobble; fit precisely and check before each heat.
• Over-lightening: Ultra-thin sections can flex or crack, wasting energy and risking disqualification.
• Paint buildup in bores: Mask holes so coatings don’t add friction.
• Ignoring rulebook details: Dimensions, minimum mass, and hole placement matter as much as speed.

Treat the car like a system—when every small inefficiency is addressed, the stopwatch shows it.

Glossary

A few key terms help decode the language of CO2 dragster design and racing.

• Drag: Aerodynamic resistance opposing the car’s motion; includes pressure and skin-friction components.
• Impulse: Change in momentum from the brief burst of thrust when the cartridge is punctured.
• Guide line: The thread or wire the car rides on to ensure straight travel and accurate timing.
• Wheelbase/track: The distance between axles (wheelbase) and between left/right wheels (track), affecting stability.

Understanding these basics speeds up design choices and communication during collaboration and judging.

Summary

CO2 dragsters are student-built, CO2-powered model cars designed to sprint down a guided track, blending excitement with real-world lessons in physics, aerodynamics, and manufacturing. Using lightweight bodies, careful alignment, low-friction running gear, and smooth finishes, teams routinely achieve 20-meter times close to a second. With proper safety, recycling of cartridges, and attention to rules, CO2 dragsters deliver a fast, repeatable platform for STEM learning and friendly competition.

What does CO2 do in a drag car?

In a typical CO2 dragster for educational or hobby purposes, the CO2 acts as the propellant by rapidly escaping its cartridge, creating thrust according to Newton’s Third Law to push the car forward. For high-performance turbo drag cars, CO2 serves a different function: it provides a system for precise boost control by using regulated, high-pressure gas to accurately and quickly manipulate the wastegate, allowing for a wider range of boost pressures and better control during a race.
 
CO2 as a Propellant 

• Principle of Operation: In miniature CO2 dragsters, a sealed CO2 cartridge is pierced, forcing the gas to rapidly exit the rear of the car. 
• Newton’s Third Law: The action of the gas escaping in one direction (rearward) results in an equal and opposite reaction, propelling the car forward. 
• Impact on Performance: The escaping gas is the sole source of propulsion for these miniature cars, making mass, friction, and aerodynamics the primary factors in determining speed. 

CO2 for Boost Control (High-Performance Engines)

• Function: High-pressure CO2 is regulated and supplied to the wastegate of a turbocharger. 
• Wastegate Control: This CO2 pressure exerts force on the wastegate, helping to hold it closed, which in turn allows for higher levels of turbocharger boost to be built and maintained. 
• Benefits:
  • Faster Spool: CO2 provides quick and precise pressure adjustments, which can help a turbo spool up faster. 
  • Wide Boost Range: It allows for greater control over boost pressure, enabling a much wider operating range from low boost at the start to high boost at the end of a race. 
  • Consistent Control: The regulated pressure of CO2 is stable and consistent, leading to more predictable and reliable boost control compared to other methods. 

What do you need to make a CO2 dragster?

Building a CO2 Race Car

1. What even is a CO₂ dragster? CO₂ dragsters are miniature racing cars which are propelled by a carbon dioxide cartridge.
2. Required Materials: (Wheels can be 3d printed from the tinkercad file) -30x7x5 cm block of wood. -two axles. -two straw bearings.
3. Required Tools: -Drill Press. -Scroll Saw. -Hacksaw.

What makes a CO2 dragster go fast?

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.

What are the three main types of CO2 dragsters?

There are 5 main types of C02 dragsters and if a C02 dragster does not fit into one of the 5 catigories, then its not a C02 dragster. They are Rail, Show, Shell, Model, and Normal.