Sauber Motorsport is based in Hinwil in the Zurich Oberland and will be an Audi works team from 2026, competing in the F1 World Championship. The Swiss motorsport experts are currently part of the Alfa Romeo F1 Team Stake. They operate their own wind tunnel to fine-tune the best possible aerodynamics, because anyone who wants to compete in Formula 1 has to work practically non-stop on improving the car and on the optimum set-up for the next race.

Measurement technology and experience

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The steel wind tunnel in Hinwil is a closed circuit 140 meters long. © Sauber Motorsport

During the tests in the wind tunnel, up to 350 measuring points with pitot tubes record the pressure distribution on the surface of the model. The forces acting on the tires, front and rear wings are measured using special scales. In a test sequence lasting 15 to 20 minutes, up to 70 positions such as the wing position or the behavior of the underbody are tested. Variables such as full and empty tanks or new and worn tires are also simulated. In addition, the aerodynamicists are in constant communication with the racing team during the training runs on the racetracks. Although the driver's experience and feeling do not provide exact data, they do provide indispensable information for finding the optimum settings. "The driver is set, the car ultimately has to work in the way that is best for him," emphasizes the wind tunnel boss. "His feedback is therefore also a very important factor for us."

The aim is always to achieve the lowest possible air resistance with the most evenly distributed downforce possible, in all driving maneuvers and in all imaginable situations. "You have to imagine the car itself as a balance," says Peter Herrsche, describing one of the particular challenges of the test work. "When braking, the nose goes down and the effect of the air resistance changes accordingly. The underside of the vehicle - which in a racing car is always very close to the ground, and in the model the distance is another 40 percent smaller - must not touch down on the rolling road. At the defined test speed, this would cause huge damage to the model and the conveyor belt. We have to be able to dynamically control this pitching movement of the model to within half a millimeter."

Precision and reliability

This means, for example, that the adjustment of the sashes must be accurate to a tenth of a millimeter. This is where the Faulhaber motors come into play. A total of eight drives are in use during a test run. Six of them move suspension and control elements, two are responsible for the wing angles. The brushless DC motors from the 1226...B series are used where space is particularly tight in the model. With a diameter of just 12 mm and a length of 26 mm, they deliver a continuous torque of 2.6 mNm. Where space is at a premium, the larger 2264...BP4 model is used with the MCBL3002 motion controller, which provides precise control. The BP4 motor is 64 mm long with a diameter of 22 mm and delivers a torque of 59 mNm.

These drives deliver the required torque from the smallest possible volume and find sufficient space even in the smallest available installation space. To adjust the suspension of the model on the ceiling of the wind tunnel, Sauber uses the most powerful brushless motor from the Faulhaber portfolio: the model 4490...B (Fig. 6) with 219 mNm, which is also combined with a motion controller, here from the MCBL3006 series. With its dimensions of 58 mm by 65 mm, the footprint of the controller, which is perfectly matched to the motor, is roughly the size of a credit card; the height is just 27 mm.

The precision of the drives was at the top of Sauber's list of requirements. But durability and reliability were also important, as Peter Herrsche emphasizes: "On the one hand, the regulations limit the duration of the test runs in the wind tunnel. At the same time, there is always the next race coming up during the Formula 1 season, for which we have to prepare the car. We can't lose a minute, the technology used simply has to be one hundred percent reliable. Faulhaber engines have been contributing to this for many years."