• Three days of testing at Barcelona (Spain)
  • Modifications for engine, suspension and aerodynamics
  • Internal project name “R13”
DTM 2007
The 2007-spec Audi A4 DTM (R13) testing at Barcelona

Since the start of the 2004 season, Audi has been involved at factory level in the DTM. Despite the restrictive regulations, which give the technicians little room for manoeuvre, a great deal has been undertaken since then: The latest generation Audi A4 DTM, which bears the project name “R13” within Audi Sport, has very little in common with the “R11” 2004 Championship
winning car.

The basic principle remains: The A4 DTM is a pure-blooded race car sporting the Audi A4 silhouette. The chassis is constructed from approximately 28 metres of aircraft quality steel tubing. The driver sits in a carbon-fibre cell which closely resembles the monocoque of a Formula 1 car. This combination guarantees the highest-level of safety. The Audi A4 DTM is assembled from approximately 6,000 parts – excluding engine and gearbox components. If all of the parts are available, the high-tech jigsaw puzzle requires about 50 hours to complete.

The Audi A4 DTM is powered by a four-litre, 90-degree V8 engine. The engine has been further refined for 2007. The peak power remains unchanged, but more power and torque is available across the entire rev range – mainly due to the reduction of internal friction. Compared to 2006, the centre-of-gravity has been lowered again. The airbox has also been modified.

“It’s not possible to make big leaps in the DTM because of the regulations,” emphasises Ulrich Baretzky, Head of Engine Technology at Audi Sport. “For these reasons it’s even more astonishing that small improvements are found year after year.”

This is also the case for the aerodynamics and the suspension. The new generation A4 DTM that completed its roll-out at Almeria (Spain) at the end of February and has just completed a 3-day test at Barcelona (Spain), is at first glance, easily distinguishable from the 2006 model from the front. The modified air ducting around the front-end is the reason.

The air flow was modified to suit the new front-end. The Audi Sport technicians spent many hours in the in-house Wind Tunnel Centre to further optimise the A4 DTM car’s aerodynamic configuration. “The 2007 A4 DTM generates more downforce, but at the same time, has a better drag coefficient,” explains Wolfgang Appel, Head of Vehicle Technology at Audi Sport.

The front suspension was also subject to extensive development; among the improvements is a new damper. Furthermore, the new Dunlop tyres require a different suspension set-up.

In spite of the comprehensive list of modifications implemented, 2007 is nevertheless a transitional year for Audi: Audi Sport is already working on the new DTM version of the A4, which should be seen in competition next year.