Speed Through Design

There are many ways in which speed can be considered in automotive design. The first and the most obvious one that comes to mind, especially when dealing with brands that have strong racing connotations like Alfa Romeo, is the contribution that design brings to the car's final performance.

Photos courtesy of Automobilismo Storico - Centro Documentazione Alfa Romeo

Every aspect of the future car's design, intended in the most complete way, from the initial design brief to the commercial launch of the model, has a strong influence on its final performance. The most important decisions, that are almost impossible to change later, involve the general layout of the car. The overall dimensions are set at the very beginning, they result from the car's market class and hence the number of occupants and luggage compartment volume. The mechanical components like engine, drive train, suspensions etc. are placed following the maker's engineering tradition. So it is the careful disposition of given elements that makes the difference.

At Alfa Romeo efficiency has always been the most important goal.

Alfa has never made big cars with big engines to achieve high performance, just the opposite, every car had to be just big enough to carry the required occupants and their luggage. Just. Not more. It is easy to understand that this design philosophy was strictly related to Alfa's racing activities that have always accompanied it through the history, there is no place for superfluous on a racing car. Consequently, every new car had to be as compact as possible as that would result in limited weight and cross section.

The weight conditions the acceleration and braking times and cross section, multiplied by the aerodynamic coefficient of the form, influences the maximum speed. Both factors condition the fuel consumption. But it's not as simple as that. When considering weight, it is not only the total number that matters but also the distribution of weight within the car's volume, because it greatly influences car's handling and road holding. The heaviest components need to be placed as low as possible to keep the center of gravity low, but also should be well distributed to achieve good weight balance between front and rear axles. Furthermore, the weight should ideally be concentrated as close as possible around the center of gravity to reduce the polar momentum of the car. And it is not finished yet. There are fixed elements of a car which weight and position never change and there are variable elements, most importantly the occupants, not only their number changes from the driver only to the maximum number for which the car is designed, but also the weight of every occupant may vary considerably. Then there is the luggage that may vary from zero to maximum capacity and the fuel tank, from full to reserve. Also here the variable weight elements should ideally be located as close as possible to the center of gravity to affect as little as possible the weight distribution between fully loaded and just the driver on board conditions.

Also in case of the aerodynamic drag it just isn't enough to achieve the smallest cross section and the best Cx coefficient which influence “only” the maximum speed.

The high speed without stability and safety are highly dangerous and hence unacceptable in any car, let alone in one that is intended to be driven fast often and in full control. Aspects as aerodynamic lift and its distribution between front and rear are of extreme importance if the full adhesion to the ground is to be guaranteed at high speeds.

That is why a negative lift or down-force, appropriately balanced between front and rear, are necessary to achieve, even, and almost always, at the cost of losing some Cx efficiency and consequently the maximum speed. These considerations help to understand the difference betwe