The Formula car is a form of open-wheel race car that has evolved from the early 1900s Grand Prix cars. Although the most well known forms are Formula One and Indycar, formula cars have been a staple of amateur motorsports, especially as a stepping stone to these top level series.
Modern amateur cars are characterized by their scratch-built single seat chassis, mid-engine rear-drive layout and aerodynamic bodywork. Non-winged versions of the formula car place emphasis on mechanical grip and cornering nimbleness.
Amateur racing classes for formula cars generally focus on designs which use a spaceframe chassis, 4 to 6 cylinder car or motorcycle engine, and fiberglass bodywork. The chassis is relatively easy to construct and repair and the engine is reasonably low cost to maintain.
Racing is generally on road course circuits and is therefore most popular in parts of Europe and the Americas where road course circuits are found.
Formula (Non-wing) Contents
|Power and Weight Stats|
|Horsepower (Typical Range)||60-225|
|Race Weight (Typical Range)||385-635 kg
Design and Construction
Race Car Models of This Type
Examples of non-wing formula cars include Formula SAE (Which optionally run wings), Formula Student (UK, optionally run wings), Formula Ford 1600, Formula Vee/Formula First, and Formula Libre.
Build Your Own Non-Wing Formula Car
Due to the scratch-built nature of formula cars, the designer must be knowledgeable in handling, chassis, suspension, powertrain, aerodynamic and safety design. These six major areas of the car design work as an integrated unit and the designer must have an understanding of how changes to one area affect the others. Much of the design work is iterative, meaning re-designing areas based on new changes to another area. After the iterations are completed, the design will be complete and optimized.
Weight Distribution: Having a good static weight distribution is important. Typically the front will be lighter in front/rear weight distribution. Left/right weight distribution should be as close to 50/50 as possible unless the car is specifically designed for oval track use.
Suspension: Maximizing the contact patch of the tires with good suspension geometry is of key importance. Suspension, wheel and tire weights (Unsprung weight) affect the compliance of the suspension, which in turn affects handling, so keeping all these components as light as possible is an advantage. The suspension pickup point locations impact the chassis design.
Chassis: Maximizing torsional rigidity is important to keep the handling responses consistent. Providing openings to make internal components accessible for maintenance is also important, and quite often at odds with the needs to maximize torsional rigidity. The cockpit opening in a spaceframe often presents the greatest challenge to achieving a high torsional rigidity.
Aerodynamic: Minimizing the drag created by the bodywork frontal area and convergence is important to maximize speed. On non-wing cars, this is an area that has a significant effect on performance along with the suspension. Where spec engines are used this area takes on even greater significance. Underbody aerodynamics may also be important and will have an effect on overall car balance depending on regulations.
Safety: Providing a substantial crash/rollover safety cell for the driver is vital as is a racing seat and racing harness. Protection for fuel storage, fire protection, and nose and sidepod crumple zones for impacts.
If you intend to race under a sanctioning body, always read and understand the regulations of your chosen racing class before designing or building any race vehicle.
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Due to the precision that is associated with the tuning and performance of formula cars, ensuring the chassis is dimensionally accurate and straight is key. The use of a solid, flat and level build space is important. Jigs are often used in this case to ensure that structural tubing stays in alignment during welding/brazing.
The builder should have solid joining and metal working knowledge and skills when fabricating the chassis/rollcage/suspension. While mild steel (1018/1020) is very forgiving, some metals are best welded using a specific method (mig/tig) and some require heat treatments before and following welding to restore their toughness and strength.
Many components for an amateur-built formula car can be sourced from small production cars (i.e. Mini) instead of being fabricated if doing so is acceptable. This will lower the overall cost. Components that are specific to racing are also generally what cause the build costs to rise, but many components must be of high quality, such as a fuel safety cell and therefore care must be taken not to "Go cheap" in the wrong places.
Because the car is scratch-built, there will be significant effort in design and construction. There is however, an equally great satisfaction and sense of accomplishment at being one of the few people in the world who have built their own race car from the ground up!
Consumable costs are reasonable in relation to other race car types—Tires probably form the single largest consumable expense. In non-wing cars, tires are often based on a treaded style (FF1600), to reduce consumable costs. Engine rebuilds and crash repairs may be more significant than other race car types, depending on the engine type and frequency they occur.
Transportation and Support Equipment