As the world finals for the 2025 STEM Racing season approaches, and the development of a more aerodynamic model becomes more difficult as we run out of ideas, the question remains, what really makes a car quick? Is it aerodynamics, or is it the physical properties, the materials, the bearings, and it will be a combination of all of them, but what really is the true determinant of the speed of a car here?
Is Aerodynamics the Key?
Most of the development of a car will go into the designing of the body and determining what will make it as go as low drag as possible. Going at speeds of 70 km/hr aerodynamics will be a factor in determining the speed of a car. The main points to consider will be how the car breaks the air, the front wing, which seems to make no sense in making it multi-layered, as that will only increase the area in which the blade hits the air.
However, a generic car as seen above will do very badly, mostly due to the significant weight of the body as well as the amount of air that hits the rear wheels is simply ridiculous. The rear wing also seems to do very little in terms of aerodynamics, although it may do something to the amount of compressed air coming out of one side of the canister.
The Role of Materials and Physical Properties
While aerodynamics plays a crucial role in a car’s speed, the choice of materials is just as important. A car that is too heavy will struggle to accelerate quickly, while one that is too light may lack the stability needed for a smooth run. The ideal balance lies in using lightweight, high-strength materials, such as carbon fiber or reinforced polymers, to maximize performance.
Beyond just the body material, the type of bearings used in the wheel assembly can have a significant impact. High-precision, low-friction bearings reduce energy losses, ensuring that more of the force from the propulsion system is translated into forward motion rather than being wasted in unnecessary resistance. Additionally, the material and surface treatment of the wheels themselves contribute to how efficiently the car rolls, affecting overall speed.
The Importance of the Canister and Launch Mechanics
Another crucial element in STEM racing cars is the CO₂ canister and the way it releases its stored energy. The canister provides the propulsion force, but how efficiently that force is transferred to the car is critical. A poorly optimized launch system can lead to energy loss due to turbulence or misalignment, reducing the effective acceleration of the car.
One area of innovation in recent years has been in refining the nozzle design to ensure a more focused and efficient release of gas. This was known as LERS system, but was effectively outlawed by the organisers as it was simply too fast to be true. The interaction between the canister and the launch pod can make or break a race, and minor variations in how the gas is expelled can lead to significant differences in final speed. Teams often test different canister placements and release angles to find the optimal setup.
Finding the True Determinant of Speed
Ultimately, there is no single factor that determines the speed of a STEM racing car. It is a finely tuned balance of aerodynamics, materials, friction reduction, and propulsion efficiency. While teams may start with an emphasis on aerodynamics, a truly competitive car must incorporate advancements in all aspects of its design.
As we approach the 2025 STEM Racing World Finals, the challenge is clear: push the boundaries of engineering, optimize every detail, and create the fastest model possible. Whether it’s through cutting-edge simulations, material innovations, or refining the launch mechanism, every team is looking for that extra edge that will make the difference between victory and second place.
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