Sneak preview of the new Audi A4 DTM

Audi Sport engineers and technicians have been working feverishly behind closed doors on the DTM race version of the new Audi A4 for twelve months. Now the time has arrived to present the fruits of their labour to the public for the first time: On Tuesday, 4 March defending champion Mattias Ekström and Head of Audi Motorsport Dr Wolfgang Ullrich unveil the new Audi A4 DTM at the Motor Show in Geneva.

The exclusive "Sneak Preview" for the media is held on the second press day in Geneva from 5:00 to 5:30 p.m. on the AUDI AG stand in Hall 1 (stand number 1061). Immediately after the world premiere the new Audi A4 DTM, which bears the project name "R14" internally at Audi Sport, is taken back to Ingolstadt. In the following week at the official DTM test at Mugello (Italy) the new A4 DTM meets the competition for the first time.

"The new Audi A4 DTM looks fantastic and feels good on the race track," reveals DTM Champion Mattias Ekström, who has already intensively tested his new machine. "I can hardly wait for the first race at Hockenheim on 13 April."

To make a championship winning car even better – the Audi Sport engineers and technicians faced this delicate task when the job of developing the DTM race version of the new Audi A4 arose. From the visual aspect they certainly succeeded: The new A4 DTM, which was publicly unveiled for the first time at the Motor Show in Geneva, spontaneously appears even more dynamic than the successful predecessor model with which Mattias Ekström won the DTM title last year.

The fourth-generation Audi A4 DTM, which bears the project name "R14” internally at Audi Sport, is also futuristic from the technical aspect. With the help of state-of-the-art CFD calculations (Computational Fluid Dynamics) particular attention was paid to the air flow running around and through the car. "In doing so we completed what we had already started last year with the R13,” explains Head of Audi Motorsport Dr Wolfgang Ullrich. "We are convinced that we have achieved the most logical optimisation of the aerodynamics allowed within the framework of the regulations.”

During the twelve month development period, which started in March 2007, a predominantly new DTM car differing in many details to its predecessor was created in Ingolstadt and Neckarsulm. "Ground breaking technical innovations on a par with quattro, FSI or TDI are not possible owing to the restrictive nature of the regulations,” says Dr Martin Mühlmeier, Head of Audi Sport Technology. "In the DTM it’s more a question of the logical interpretation and implementation of the technology allowed.”

In the process it was possible to reduce the car’s centre of gravity height and to further reduce the dry weight, which in turn gives the race engineers more flexibility to set the car up to suit specific race tracks and the weight distribution.

The technicians even found development potential in the four-litre near 460 hp V8 engine used in the Audi A4 DTM. The internal friction was further reduced which in turn benefited the power produced and torque curve.

The basic principle of the vehicle, which is stipulated by the regulations, remains the same: The A4 DTM is a thoroughbred race car with the silhouette of the new Audi A4. The chassis has a hybrid concept. It consists of almost 31 metres of steel tube of the type also used in the aerospace industry. The driver sits in a carbon fibre safety cell that actually resembles a Formula 1 monocoque. This combination guarantees the highest torsional stiffness and safety.

The bodywork is made from carbon-fibre composite and is – in spite of all the aerodynamic gadgets – immediately identifiable at first glance as an Audi A4. The distinctive brand styling-elements like the Single Frame grille and the white LED daytime low-beam lights ensure that the face of the A4 DTM has the same unique look like the road going model.

The most important components of the new DTM were tested immediately after the end of the 2007 DTM season. The first R14 prototype completed its roll-out shortly before Christmas at Le Castellet (France). Before its race debut on 13 April at the Hockenheimring, the new Audi A4 DTM will have spooled off several thousand test kilometres – including endurance tests.

"The new road going A4 has already won many international awards in a very short period of time,” says Dr Wolfgang Ullrich. "We aim to do these awards justice with the new DTM. We are convinced that the new Audi A4 is an excellent base for a successful DTM car.”

Defending champion Mattias Ekström, who unveiled his new company car in Geneva together with his boss, prefers not to make any predictions at the moment: "If the new A4 DTM is as quick as it looks then I’ll be satisfied,” says the Swede diplomatically.

The new Audi A4 DTM meets its future opponents for the first time at the official DTM test between 10 and 12 March in Mugello (Italy).

The Audi A4 DTM introduced last season set a record at its début: With six victories, eight best times in qualifying and the title win, it was the most successful DTM vehicle based on the A4, which Audi has designed and built since its return to the DTM in 2004. In accordance with the internal model designations, R11 (2004), R12 (2005), R12 plus (2006), R13 (2007) and R14 (2008), the current R14 plus (2009) represents the sixth generation of the vehicle.

The engineers from Audi Sport in Ingolstadt and Neckarsulm were faced with a difficult task: the challenge of improving the champion’s car from the year before yet again, within unchanged confines of the regulations. All of the principal design features of the touring race car, which is based on a tubular frame and a carbon fiber shell for the driver, and powered by a 460-hp four-liter V8 engine, have remained the same.

“The most clearly visible modification that is visible when the hood is open concerns the air box above the engine,” explains Ulrich Baretzky, Head of Engine Development at Audi Sport. It is a consequence of the requirements that arose
from a new cooling air passage at the vehicle’s front. The charge changing process – meaning the inflow of fresh gas following the outflow of exhaust gas – has been optimized by the new intake plenum. Audi has also achieved improvements in torque development and power output, in other words the engine’s drivability. One of many other detailed optimizations concerns the more favorable oil circuit. When summing up the total of their achievements, the developers’ have to make a realistic assessment. “Basically, in the sixth year of continuous development, the potential of any engine design has been fully exploited,” says Ulrich Baretzky.

Wolfgang Appel, Head of Vehicle Development, and his team clearly defined some focal areas with respect to the development of the other components of the car as well. “Even though we compiled a list of about 80 minor or major items on the whole vehicle, we clearly concentrated our efforts on aerodynamics,” says Appel. “We modified various aspects of the air flow around the vehicle, the diffuser and the flow through the engine compartment.” A rear wing mounted from
the top, which promises to provide better flow characteristics, is a conspicuous feature. This idea made its début with the Audi R15 TDI Le Mans sports car this year. The aerodynamic effects of new solutions are first calculated using computational fluid dynamics (CFD), followed by model wind tunnel testing and – ultimately – by testing at AUDI AG’s full-scale wind tunnel.

Furthermore, the engineers focused their attention on all aspects which contribute to maintaining the performance capability of the race car at consistent levels across the racing distance of typically more than 60 minutes. Two
significant factors determine the sporting result: the way the car handles the deterioration of the tires over the course of time as well as the reduction in vehicle mass caused by the consumption of the fuel in the tank. New components of the braking system are an additional aspect. The British manufacturer AP, who equips all DTM vehicles with a standard system, presents clearly less massive brake calipers for the 2009 season. “This influences our choice of aerodynamic flow toward the brake,” explains Appel. “The clearly improved air flow through the calipers will also guarantee higher consistency during the race.”

Audi Head of Motorsport Dr. Wolfgang Ullrich is certain: “With the R14 model last year we developed the most competitive concept based on an A4 so far. This race car possesses enough potential to again fight for the place at the top this year as the R14 plus. After all, our goal is to defend the title.”