With four titles in three years: the vehicle designation BMW M4 DTM is synonymous with great success. Marco Wittmann won the Drivers’ title with this car in both 2014 and 2016. BMW Team RMG also picked up the Teams’ title in 2014, while BMW won the Manufacturers’ Championship in 2015. This year sees the dawn of a new era. In the light of the new regulations, the BMW M4 DTM has been given a workover and undergone significant development. The BMW M4 DTM now generates over 500 hp of engine power, while the aerodynamics have also been the subject of extensive modifications. Innovative technology was used when manufacturing the components.
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.
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 mm to 2 x 29 mm, 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. 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 drivers to react to the circuit and engine characteristics when setting-up the car.
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-fiber 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 DTM racer. They literally give the car a “dynamic look”, while the redesigned rear lights further add to the appeal of the BMW M4 DTM, when viewed from the back.
Edited: BMW Motorsport