DTM

Safety in DTM with Opel

When the technical regulations for the DTM, which was relaunched in 2000, were first established, safety was stressed as a major integral component and has been continually expanded since then. "Elements like space frames, carbon fibre monocoques...

When the technical regulations for the DTM, which was relaunched in 2000, were first established, safety was stressed as a major integral component and has been continually expanded since then. "Elements like space frames, carbon fibre monocoques and crash boxes comprise a unit with exactly defined maximum load and stress values that must be confirmed by tests," said Opel motorsport boss Volker Strycek. "The DTM cars are currently representing the ultimate in safety standards."

Loads of eight tons in test stand trials

The DTM driver has exchanged his racing seat, which used to be bolted to the chassis, for a safety cell that basically equates to a Formula 1 monocoque. This carbon fibre cell contains the six-point safety belts, the in-molded seat bucket, the pedals and, with Opel, the fire extinguisher reservoir as well. "Dimensions, load and stress values are precisely specified," said Dr Ulrich Pfisterer, DTM project manager of Opel Performance Center (OPC). The cell, which must weigh a minimum of 25 kilograms, must be confirmed to hold up to a load of just under 8 (metric) tons in test stand trials - and over a period of 30 seconds at that. "At first, sitting in such a box was an unfamiliar experience, but now, I wouldn't want to do without this safety element any more," said Michael Bartels (Opel Team Holzer).

A head restraint eclipsing the driver's head on the sides is an integral component of the safety cell and seat shell unit. Opel had a major part in initiating this development. Due to the lateral extension of the head restraint, the seat came to be nicknamed as a "wing chair." The maximum distance prescribed between the two lateral supports is 40 centimetres, and even the head restraint must be able to resist a load of nearly one and a half (metric) tons. Both the carbon fibre cell and the space frame must be cushioned with crash-absorbing materials in the vicinity of the driver. Regulations specifically require the use of Neopolene foam by BASF for this purpose.

Frame comprises 85 metres of steel tubing

The "seat box" is firmly bolted to the tubular frame. More than 85 metres of steel tubing - specifically speaking: standard 115 CrMo 14 aviation steel - were used for the frame structure, following in-depth engineering calculations and clear specifications established by the regulations. After all, the tubular frame not only ensures the requisite stiffness of the body, which influences the driving properties of the V8 Coupé, but is also an integral component of the overall safety concept. The impressive tubular construction, which has nothing in common with the roll-over bars of the past, must be able to resist exactly specified stress parameters as well. As such, the tubular frame in the vicinity of the B-pillar has to be able to withstand a vertical force of up to nine (metric) tons, with only a maximum 25-mm deformation of the roll-over section permitted.

Crash tests for crash boxes

Whilst static load and stress tests are prescribed for the preponderance of the parts, all of which are monitored by Deutscher Motor-Sport-Bund (DMSB), the crash boxes installed at the front and rear must be subjected to both static and dynamic testing. Similar to the crumple zones in production vehicles, the impact structures made of carbon fibre are mounted to a sled, simulating a vehicle crashing against a concrete wall at a speed of 46 kph. The permissible deceleration values of 40 g on average roughly equate to those of a production vehicle. The testing buck weighs a total of 1,200 kilogramms, approximately the same as a DTM vehicle with a full fuel tank.

HANS improves driver safety

The HANS system, which made its way into the series last year already, has since become an integral element of the safety package. HANS stands for „head and neck support." HANS is a carbon and aramide fibre supporting device resting on the driver's shoulders and pressed against the body by the shoulder belts. Fastened to the driver's helmet by two flexible connections, HANS, an U.S. development, provides better support to the cervical vertebrae, whilst reducing the biomechanical forces exerted on the head and neck in case of an impact. "HANS is an excellent invention that has already proven its worth time and again," said Manuel Reuter (Opel Team Phoenix), whilst Yves Olivier (Opel Euroteam) added: "HANS offers major benefits, although the system reduces mobility as well as limiting the driver's vision to the right and left."

Out of the cockpit in 3.9 seconds

Despite fireproof underwear, headgear and racing overalls, despite fire extinguisher systems and fire protection walls between the engine compartment and the cockpit as well as the safety tank, the driver's ability to leave the cockpit at lightning speed can be crucial in case of a crash. To ensure that this can be done DTM regulations impose specific requirements: Wearing full gear and belted into the seat, with the steering wheel in place and the doors closed, the driver must be able to leave the cockpit in seven seconds through the door on his side, which must be capable of being opened - and in nine seconds through the door on the co-driver's side.

At the DTM season opener at Hockenheim, all drivers had to pass this test, which Opel's Michael Bartels, Alain Menu, Yves Olivier, Manuel Reuter, Timo Scheider and Joachim Winkelhock mastered superbly. The quickest, by the way, was Timo Scheider, who also scored the first championship points for Opel: The 23-year-old climbed out of the cockpit in a mere 3.9 seconds.

-opel-

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About this article
Series DTM
Drivers Joachim Winkelhock , Manuel Reuter , Timo Scheider , Michael Bartels , Yves Olivier , Volker Strycek , Alain Menu