[Video] Detailed look at the BMW M4 DTM for the 2017 season

BMW Motorsport is first race of the 2017 DTM season at Hockenheim (GER) with a very experienced driver fleet and the BMW M4 DTM developed according to the new technical regulations.

The regulations required the BMW Motorsport engineers to take a new approach to aerodynamics when developing the BMW M4 DTM. A shorter diffusor and the fact that the ride height has been increased in line with regulations, reduce downforce and ‘dirty air’. The flow topology around the car was completely revised. The front bumper now has a completely new shape and forms the starting point for the flow of the air around the car. The wing mirrors will have a more conventional design again in 2017 according to the regulations. Among the many clearly visible modifications are the even more prominent contouring of the side channel, the vent ducts on the rear wheel arches, which are being used for the first time, and the incredibly detailed design of the rear of the car.

The rear wing is also one of the more easily recognisable changes to the 2017 DTM cars. The Drag Reduction System (DRS) has been modified. Up until now, the rear wing consisted of just one profile and was lowered as one part when DRS was triggered. The rear wing of the new BMW M4 DTM is made up of two profiles, with the just the top profile tilting upwards when DRS is activated. Unlike before, the end plates no longer move with the wing. The range of adjustment for the system is up to 40 degrees for 2017, making it more efficient than last year.

The front splitter and underbody of the DTM cars are standard components, in accordance with the new regulations. The same goes for the floor panel, which is five millimetres thicker than before. The rear diffusor also has a completely new shape and is shorter and flatter than that of the previous model.

Over the course of the aerodynamic development of the new BMW M4 DTM in the BMW Group’s Aero Lab, the engineers had to be even more efficient than usual: they had just 50 days in which to test the new model in the wind tunnel and to optimise it. As a result, CFD calculations, simulations and the rapid prototyping of components from wind tunnel models played a more significant role.

When it comes to the engine, the DTM regulations for the 2017 season allow a larger diameter for the air restrictors, through which the engine draws in its combustion air. Having enlarged the air restrictors from 2 x 28 millimetres to 2 x 29 millimetres, the charge cycle was adapted accordingly. This increased the engine performance by about 25 hp to over 500 hp. Because the engine, now known as the P66/1, takes more cooling, due to the increased performance, the cooling air intakes towards the front of the car were also modified. As another consequence of the greater power, even more powerful and durable carbon-fibre brake disks are also used in the DTM in 2017.

In its final spec, the BMW V8 engine consists of almost 800 different components. In total, the powerhouse is made up of almost 4,000 individual parts. When designing the DTM power unit, BMW took full advantage of the technological know-how of the BMW Group. The high-tech foundry at the BMW plant in Landshut contributed the large castings, such as cylinder heads and crankcases. The processing of the castings, their coating, and any necessary thermal treatment, was performed by the appropriate specialist departments in Munich.

BMW Power continues to be transferred to the track via a six-speed, sequential racing transmission, which is operated pneumatically via shift paddles on the steering wheel. It has eleven transmission ratios, which allow the engineers and drivers to react to the circuit and engine characteristics when setting-up the car.

The engine mount is a complex structural component, which is placed under great strain, and connects the engine frame to the engine. It was manufactured specifically for the DTM car using an additive 3D printing procedure and optimised using topology.

The chassis for the 2017 DTM season consists of many standard parts: shock absorbers, anti-roll bar, wishbone, wheel mounts, wheel hubs and wheel nuts are now prescribed as standard. However, the BMW Motorsport engineers had free rein when it came to the side springs and the third element of the front axle, as well as the configuration and layout of the standard parts.

The carbon-fibre monocoque is again instrumental in ensuring the safety of the drivers in the new BMW M4 DTM. With an integrated tank, steel roll cage, and additional crash elements, it provides effective protection for the driver in case of an accident.

The interaction between the chassis and the 2017 generation of Hankook race tyre was also of great importance. With a new design and new compound, the DTM’s tyre partner is adding another exciting element to the coming season. The new dry tyre for the DTM – the Ventus Race – will generate greater grip than its predecessor when in good condition. In contrast, however, it will degrade faster and more dramatically, depending on the driving style. This is what the car manufacturers and organisers had intended, and it will have a significant effect on lap times.

Finally, new, characteristic LED front lights round off the appearance of the 2017 model. They literally give the car a “dynamic look”. The rear lights have also been redesigned.