The foundation of weight saving in F1 is material choice. Each individual component starts with design engineers performing calculations and tests to figure out what material yields the best strength-to-weight ratios. The monocoque is a prime example of this. It uses pre-preg carbon fibre, a carbon fabric that is pre-impregnated with resin, which is laid up in certain orientations to provide strength where it is most needed. Making a component out of thick carbon and hoping it is strong enough, is not how it is done at F1. Using Finite Element Analysis (FEA), engineers determine where the most stress will occur, and on the carbon layers, provide strength and reliability in the high stress areas, while on the lower load areas, using fewer layers of carbon to save weight and not compromise on safety.
Titanium is an integral part of Formula 1 weight-saving strategies. Grade 5 titanium (Ti-6Al-4V, specification AMS 4928) is strong, lightweight, and weighs 60% as much as steel, offering excellent strength. Titanium is also used throughout the car for suspension components, brake caliper pistons, and fasteners. For instance, a titanium suspension pushrod weighs 80 grams, while the steel version weighs 200 grams. Across hundreds of components, the weight savings is substantial.
Some teams use beta titanium alloys Ti-10V-2Fe-3Al (AMS 4984) for even better performance. This material is stronger than standard Grade 5, allowing even smaller cross-sections and greater savings. Though it is more expensive and more challenging to machine, in F1, it is worth the downsides if it means saving weight.
Attempts to save weight must be applied to the fasteners of a car as well. An F1 car is made up of thousands of various fasteners like bolts, nuts, and screws. For each fastener, switching from steel to titanium can save about 10 grams. For 2,000 fasteners, that is a total of 20 kilograms (which is a noteworthy amount of weight). Unless there is a reason not to, teams systematically go through the car and replace each steel fastener with titanium. For some fasteners, there are even more exotic materials used like aluminum-bronze and aluminum-lithium alloys, particularly where the loads are low.
Another weight saving opportunity lies with hollow components. Instead of solid screws, F1 teams save weight in solid bolts by using hollow ones. A solid titanium bolt can be replaced by a hollow one, and the strength reduction is virtually nonexistent since the center contributes very little to the bolt’s overall strength. A weight saving of 30 to 40 percent is noteworthy. F1 teams hollow out suspension components, steering columns, and any other components where the inner material doesn’t add to the overall strength.
Along with 2099, specification AMS 4462, lithium aluminium alloys are another option for weight savings. These alloys are roughly 10% lighter than conventional lithium aluminium alloys, while offering comparable strength. For components like suspension uprights or gearbox casings, 10% weight saving is clinically important, although lithium aluminium alloys are high cost and difficult to work with. The material price is roughly triple that of the standard 7075 aluminium, however, in F1, this is an acceptable cost.
Further weight savings can be achieved with magnesium. Weighing in at approximately 66% of the weight of aluminium, magnesium can be used for components that do not require the strength of aluminium. AZ31B (AMS 4375) and the stronger ZK60A are common magnesium alloys used for gearbox housings. Magnesium is more expensive than aluminium and more difficult to work with since it can ignite if too much machining is done, but the weight savings are justifiable.
Optimisation of weight during manufacturing is critical. In the past, solid metal billets were machined to create components. This involved starting with a large block of metal and removing material to create the desired shape. Nowadays, F1 teams are using additive manufacturing, or 3D printing, to create components from titanium and aluminum alloys. This technology enables them to construct complicated internal designs that cannot be achieved by standard machining, such as an internal lattice structure in a 3D printed titanium bracket, which strengthens the bracket and minimizes material in other areas. This results in components that are 40 to 50 percent lighter than those made by conventional machining.
With the aid of additive manufacturing, Topology Optimisation software is creating structures that use the least amount of material possible. This software generates the optimum shape to withstand the loads and constraints provided by the engineers. The results are innovative and efficient, exhibiting the best material usage, while traditional manufacturing methods cannot construct them. This is where 3D printing becomes necessary.
Even fastening techniques result in weight savings. Regular bolted joints take up extra material at the hole perimeter for load distribution. Structural adhesive bonded joints can be lighter since the load distribution is more optimal with the adhesive. F1 teams bond carbon fibre parts whenever possible using aerospace adhesives which have strength attributes similar to mechanical fasteners. This also provides the bonded joint some stiffness advantages since the bonded joint can be stiffer than a mechanical joint.
Weight distribution is as important as total weight. Engineers want the car to be light with the weight low and centrally placed. Batteries, oil tanks, and coolant systems are as low as possible to lower the center of gravity. If you save 500 grams from a component positioned higher up in the car and replace it with 500 grams of ballast lower down, you have improved the handling even with no change in total weight.
Surface treatments and coatings are shackled with the every gram document focuses on excess weight. Traditional paint can add 2-3 kg per car. A few teams use less paint and cover the carbon fiber components with just a clear coat. When paint is needed, teams use it in thin layers and try to avoid covering it.
Cable routing is also optimized. Less length means less weight in the cables. Saving hundreds of grams can come from running wires in an efficient, rather than a circuitous, manner. Where possible, wiring harnesses use lighter gauge wire and the minimal weight connectors that are specified for reliability.
The demands of the documentation are also interesting. Descriptive labels and identifying marks are needed on components. Teams use the lightest materials for these labels, and try to position them so that they will not disturb any of the aerodynamically critical surfaces. When margin is not needed and the goal is to hit weight targets, every detail becomes critical.
Some teams run ballast because they have made the car too light and need to reach the minimum weight limit. This enables them to control weight distribution because they can choose where to center ballast instead of being stuck with what the natural weight of other components are. Most teams, however, prefer to design components to meet target weights exactly, avoiding the need for ballast, and keeping greater distribution of weight adjustment throughout the season.
Weight savings are always sought after. Even when the car reaches the limit, engineers are still trying to save weight because they can be forced to add parts mid season, or changes to the regulations can occur. This also allows for added components during the season. In the world of F1, 100g can be the difference from pole position and 2nd row.