

DTM will look slightly different in 2014 after all three manufacturers in the series homologated new aerodynamic packages for the cars. Whilst the championship could be perceived as a spec class the 2014 cars are all quite different to each other in a number of areas despite sharing many common parts including the chassis.



BMW has gone the furthest homologating an all new model, the M4. “Even before the BMW M3 DTM completed its final race last season, our development team was already hard at work on the 2014 car,” said BMW Motorsport Director Jens Marquardt.

“Preparing a new car for the DTM is a big challenge. In few other series is aerodynamics so important. Even the slightest detail can make the difference between success and failure. And this attention to detail shown by our engineers is apparent at first glance – from the elongated bonnet with its steeply sloping front and aerodynamically optimised wing mirrors, to the contoured roofline that is a characteristic feature of the BMW M4.”

The first scale model made its first appearance in the wind tunnel at the BMW Group’s Aero Lab on 22nd April – 13 days before the opening race of the 2013 season at Hockenheim. In the summer of 2013, while continuing with aerodynamic testing, the experts in Munich turned their attention to designing new suspension parts. The new components made their first on-track outing in December 2013 – but still within the BMW M3 DTM at that point. The final parts for the chassis of the BMW M4 DTM were in production by the turn of the year, allowing the BMW teams to assemble the first models of the new car in January and February. Three hundred days after the first test in the wind tunnel, the BMW M4 DTM took to the track for its track debut at Monteblanco on 11th February 2014.



Aerodynamics plays a vital role in the DTM in 2014 and it is here where most changes can be seen. “In addition to the suspension, our main priority was to improve the aero,” says Stefan Aicher, Head of Vehicle Design at Audi Sport. The RS 5 now has the honeycomb grill from the production car at the front and new air ducts feeding the engine and brakes.



Developing the M4 the BMW Motorsport engineers devoted a lot of time to issues such as aerodynamic drag and through car air flow.



A new feature on the BMW is a plate along the side channel, which lends the racing car an even more striking outline (above). Audi in comparison has a series of winglets in this area (below).



The slightly contoured roofline (below) decreases the frontal area of the car and in turn further reduces aerodynamic drag. The flatter rear window optimises the way the airflow approaches the rear wing.



The wing mirrors, have been a major area of development for all three manufacturers, with very different approaches being taken.



BMW has opted for a relatively conventional wing mirror shape but has mounted it on a winglet, which has two elements at the outer edge and an endplate, rather like a mini F1 front wing (above). But Audi has taken a different approach (below) with a triple element wing support



Finally Mercedes, which has revealed very few details of its 2014 car has the most simple looking solution (below).



The inner rear wheel arches are, in contrast to last year, closed and the rear part is now flat.



Aicher: “The DTM rules are strict, which is why minute detail work is required within the tight limitations.”



Over 50 of the 5,000 plus parts that make up the DTM cars are standard components, which are used on all three designs.One of these parts is the chassis with an integrated fuel tank, steel roll cage and additional crash elements.



DTM shares its basic design with the 2014 GT500 mother chassis, though there are some differences, compare the GT500 version (in Honda mid engined trim – below) with the DTM Spec tub (above)



Parts like the gearbox, clutch, dampers and rear wing are identical in all DTM cars. This also keeps a lid on development costs.



One area where there is significant difference is the engine, all three cars use four litre V8 engines producing around 480bhp.

The BMW P66 for example is made up of 800 different components, consisting of 3,900 individual parts. When designing the DTM drivetrain, BMW Motorsport took full advantage of the technological know-how within the BMW Group. The high-tech foundry connected to BMW Plant Landshut creates the large cast parts, such as the cylinder head and crankcase – just as it does in the production of the six-cylinder in-line engine for the BMW M4 Coupé. The cast parts are coated and given the necessary heat treatment within the appropriate departments in Munich. HWA and Mercedes-Benz HPP prepare the engines for Mercedes whilst NBE is believed to still produce the DTM engines for Audi Sport

The era of the big four litre V8’s is coming to an end however, in 2015 or 2016 a new two litre four cylinder engine formula will be introduced, bringing the German cars closer to the Japanese cars racing in GT500.



The engine’s power is transferred via a sequential six-speed racing gearbox, which is operated pneumatically using shift paddles mounted on the steering wheel. The gearbox is one of the standard components, it has 11 final drive ratios, which allow the engineers and drivers to react to the respective circuit and engine characteristics when setting the car up.

As standard components, the engine subframe at the front and gearbox at the rear restrict the engineers’ freedom to design the suspension geometry. The suspension pick-up points must be mounted to these standard elements so are largely identical. In addition, tube dimensions and the material, steel, for the wishbones are fixed and numerous dimensions are defined by the regulations – those of the wheels for example.

The future of DTM

There are ongoing discussions behind the scenes about a new North American DTM series using cars from both GT500 and the German series, whilst the Japanese brands have not ruled it out they have also shown little enthusiasm. Meanwhile the Germans have admitted that for DTM USA to happen there would have to be at least one American brand involved, and seemingly none have shown interest. However there does seem to be a chance that the GT500 and DTM designs will be seen racing in the USA in years to come as part of the prototype class in the United Sportscar Series a tantalising prospect.

Much of the background and further details of the unification talks can be read in Racecar Engineering magazine below.



READ IT NOW DTM AND GT500 THE FUTURE REVEALED

IMAGES – DTM 2014

[Show as slideshow] Audi RS5 DTM 2014

[Show as slideshow] BMW M4 DTM



Mercedes 2014 DTM

GT500 2014

[Show as slideshow]

[Show as slideshow]



Lexus LF-CC (RCF)

Much of the background and further details of the unification talks can be read in Racecar Engineering magazine below.



READ IT NOW DTM AND GT500 THE FUTURE REVEALED