Keeping the costs under control, providing motor racing at a high technical level combined with the best possible safety – that’s the magic formula used for creating the DTM regulations. And for the 2017 season, the technical regulations were significantly revised for the first time since five years. The cars for the 2017 feature numerous new components and differ significantly – both under the skin and regarding the bodywork – from their predecessors. To make sure that the costs are kept on a reasonable level, DTM keeps on relying on a perfected concept with control parts. Nonetheless, the engineers have got enough latitude in the areas aerodynamics and engine for proving that they are better than their competitors.
The aerodynamics of the new DTM vehicles were modified to reduce the downforce produced by the cars. The geometry of front splitter, underbody and rear diffuser was standardised. Furthermore, the ride height was increased by five millimetres what makes a massive impact on the aero performance. In addition, the DRS (Drag Reduction System) was redefined. The rear wing now is inflexible, with the upper two flaps being opened by pressing the respective button. The new system therefore features an even higher efficiency and increases the top speed what will result in a bigger number of overtaking manoeuvres. The rear-wing flaps move back into their closed standard position when the driver decelerates or a certain level of lateral forces is exceeded. So, the driver never gets into a critical position and it is prevented that the reduced downforce results in an unstable car. As result of the aero modifications, the handling of the new DTM vehicles represents a bigger challenge for the drivers.
The DTM vehicles feature a high-performance brake system with alloy brake callipers and ventilated carbon-fibre brake discs at the front and the rear. The brake-power distributor can infinitely be adjusted by the driver. Over the course of the season, three sets of brake discs and nine sets of brake pads each for the front and the rear may be used per car.
All the manufacturers involved in DTM work with an engine control unit supplied by Bosch. They are allowed to write the software for the ECU themselves. Data transfer to the ECU while the car is driving is prohibited.
The suspension was completely revised for the 2017 season and mainly consists of control parts.
From the 2017 season, all the cars on the DTM grid – no matter what brand – will contest the races on forged ATS wheels. These wheels are aluminium wheels in the dimensions 12x18 for the front axle and 13x18 for the rear axle. The new wheels are made of a high-tensile special alloy and meet the highest demands regarding rigidity and precision. The minimum per front wheel amounts to 9.5kg and per rear wheel to 10kg.
There is a radio link between each car and the pits. But there are rules defining when the engineers may contact the drivers with information and / or instructions. During the entire race (from the start to the finish line) radio contact from the pits to the car is generally interdicted. Allowed are safety-relevant messages if yellow flags are shown or a slow zone is indicated, during a safety-car phase or while a driver is in the pit lane. The driver, however, may contact his team to provide it with information at any time.
Just one control gearbox-differential unit by Hewland has been approved for DTM and consequently is used by all the manufacturers. The clutch is acknowledged by ZF. All the vehicles feature rear-wheel drive, a four-disc CFL clutch and a sequential six-speed gearbox.
The minimum weight of a DTM touring car including driver, racing gear, helmet and 12.5kg performance weight amounts for all the cars to 1125kg. The performance weight that has to be used is defined by the sporting regulations depending on the respective drivers’ performance. The performance weight consists of standardised 2.5kg ballast blocks made of wolfram that are attached to the car in the underbody.
The only fuel that is allowed to be used is the one stipulated for the respective event (ARAL Ultimate 102). The tank capacity amounts to 118 litres.
The steering wheel may be adapted to a driver’s individual liking. The gears are changed by paddles mounted at the steering wheel. The systems that can be controlled via the wheel have been stipulated, such as the pit radio, the beverage pump, the pit-lane speed limiter, the water-spray system for cooling the brakes, the windscreen wiper, the starter as well as the DRS activation.
In DTM, solely 90-degree V8 engines with a maximum capacity of four litres and four valves per cylinder are used. The air-inlet system must be equipped with two air restrictors. The diameter of these air restrictors was increased from 28 to 29 millimetres, for the 2017 season. Only one reserve engine per manufacturer and season is allowed.
The tyres exclusively are supplied by series partner Hankook, with the dry-weather tyres having been newly designed, for the 2017 season. The front wheels are shod with tyres of the latest spec of the Ventus family in the dimensions 300/680-18 and the rear wheels with the same tyres in the dimensions 320/710-18. Compared to its predecessor, the new tyre produces more grip but also has to cope with a bigger performance drop. Eight sets of tyres are available for every driver per weekend for all the sessions (training sessions, practice sessions and races). Tyre warmers for the slicks are prohibited from 2017.
In the cockpit, the DTM driver is surrounded by an innovative combination of control monocoque and control roll cage. In addition, all the DTM cars are equipped with crash structures at the sides, the front and the rear that are supposed to absorb energy as much as possible in the case of an impact. Wearing the Head And Neck Support system HANS became obligatory as early as in 2002. Furthermore, the DTM vehicles have got a removable hatch in the roof that allows the rescue team to get to the driver in the case of an emergency. From the 2017 season, DTM also meets the new safety standards for safety harnesses. The safety standards achieved in DTM are unique and unmatched in touring-car racing all over the world.