DTM technology from a single mould.


Landshut DTM foundry as competence and prototype centre.

  • Maximum flexibility at the highest level of quality.
  • Process expertise from within own ranks.
  • Technology transfer from racing to series production and vice versa.
  • Shorter development times through rapid prototyping technology.

Speed and precision top priority.
Speed and precision are top priority in the DTM German Touring Car Championship. This applies not only to the drivers on the racetrack, but to everyone behind the scenes who contributes to the success of the BMW M3 DTM team. Only those teams with the necessary skills and flexibility can compete against the fastest in the world in the DTM championship.
Take the example of casting technology: The DTM foundry is located 65 kilometres northeast of Munich, in Landshut. Here a team of foundry experts with a wealth of specialist know-how has been working on the development of the new DTM engine for about a year.

Synergies through networked in-house expertise.
The BMW Group has set up a Sand Casting Technical Competence Centre at its Landshut plant, right next door to the light-metal foundry which produces cylinder heads and crankcases for series-produced BMW engines. This highly-specialised foundry for prototypes and small-series vehicles provides the ideal conditions for transforming the BMW M3 DTM engines into the strongest and most reliable in racing.
As a prototyping centre for the development of components for future BMW Group series-production engines, Landshut’s Technical Competence Centre also produces test parts as well as crankcases and cylinder heads for the BMW M3 DTM’s V8 engine.

The Sand Casting Technical Competence Centre is manned by a veteran team recruited exclusively from among light-metal foundry employees. In light of the small quantities produced and the flexibility required, experience and manual dexterity are indispensable. The BMW Landshut Plant foundry team is also closely involved in the process of developing new engines both for BMW Motorsport and series development.
Since the entire process chain from model making through casting to quality control is all under one roof, it is possible to respond quickly and flexibly to changes. For instance, the Sand Casting Technical Competence Centre has its own model-making department with its own CAD experts. Here, sand core moulds can be modified or remade. Perfectly-coordinated change and quality management for processes, as well as the proximity to BMW Motorsport in Munich, allow castings for DTM M3 engines to be modified at short notice.

No such thing as impossible.
Focusing always on maximum precision, the foundry team works with engine developers to turn the impossible into reality on a daily basis. Racing engines’ technological potential has been exhausted to such an extent already that modifications depend on the expertise of experienced production specialists acquired over decades, as well as ground-breaking processes and tools. Time and again, the Landshut foundry experts have redefined what is possible in casting to produce components with a level of complexity and quality that could never have been achieved before.
The crankcase and the two cylinder heads are just three of several hundred individual parts that comprise a DTM engine but more development effort and process expertise goes into these parts than any other automobile component.

Sand casting expertise.
The fast pace of development for DTM engine components which may require modification every two weeks is only possible thanks to highly-flexible sand casting procedures. To produce DTM engine components, the Landshut foundry specialists have substantially refined the sand casting process that has been used for several thousand years. Sand casting provides a particularly broad freedom of design, combined with excellent flexibility for changes and short processing times.

In this process, negative moulds are created from cured sand cores which are then recast. Using this rapid and easily-adaptable technique, roughly 750-degree molten aluminium is poured into a complex sand mould that as a negative mould is made up of up to 20 different sand cores. The individual sand cores are formed into a complete core package entirely by hand. Foundry experts with years of experience and considerable manual dexterity piece together the three-dimensional, but extremely fragile, puzzle to form complete moulds.

Besides the handling of the molten aluminium and precise control of pouring speed and temperature during the casting process, the structure, manufacture and assembly of the sand cores also have a decisive influence on the quality of the casting. The sand cores must model both the engine component’s external form and its required openings. Due to the thin-walled, compact design of the BMW M3 DTM engine, the sand cores for the engine components are especially delicate.
The art lies in modelling components with a tolerance in the tenth of a millimeter range using conventional quartz sand. To meet strict quality requirements, DTM specialists use only highest-purity aluminium for cast components for the V8 engine.
However, sand casting can only be used to produce limited quantities, since every sand mould can only be used once: At the end of the casting process they are destroyed to release the actual casting. 96 per cent of the sand used is recycled and reused later in the process.

Rapid prototyping: sand cores at DTM-speed.
The BMW Landshut Plant’s Sand Casting Technical Competence Unit uses a specially-developed rapid prototyping technology for accelerated sand core manufacture. A so-called 3-D core pressure process allows sand cores to be produced directly from the design data for the engine components without the use of tool moulds. The Landshut foundry also employs rapid prototyping technologies for the production of sand cores for prototype and trial engines, which significantly reduces the time required for trial processes during the development of series-production engines.

Competence in virtual validation.
Chance is not a factor in the casting process. In many test series, the filling and solidification processes are virtually simulated to optimise flow paths and identify and correct potential faults before tools are made.
As soon as the metal poured into the mould has solidified and cooled, the sand cores are destroyed and the casting released. The raw part can then be sanded using a handheld sanding tool and treated by heat to ensure optimum material properties such as tensile strength and elongation. After submitting to meticulous quality controls, the DTM castings are then shipped to Munich for mechanical finishing.

Quality comes first.
The manufacturing process for the castings used in DTM M3 engines must be stable and reliable in order to meet the high demands placed on the engines on the race track. The only way to achieve this is by applying highly-efficient quality assurance methods since results can only be reproduced and used for further optimisation when nothing is left to chance.
Because unlike Formula One engines DTM engines have to last not just one or two races, but a whole season. The BMW M3 DTM’s V8 engine must withstand roughly 11,000 revolutions per minute and up to 2,000 degrees Celsius combustion temperature during a race. This means that the highest-possible quality is only good enough for the DTM specialists in Landshut.
Material samples from the melt are used for quality assurance purposes in the same way that computer tomography is used in medicine. This allows non-destructive inspection of all components produced by the Sand Casting Technical Competence Centre for instance, by verifying whether the measurement data for difficult-to-access spaces corresponds with the design data, or whether there are defects in the material. Landshut has also introduced a “virtual factory” to track parts throughout the on-going production process and achieve 100-percent quality assurance for the DTM process. This allows the smallest detail in the manufacture of every single component to be traced, and possible deviations identified.
The weight of the component is also tremendously important, besides quality: The crankcase of a series-produced V 8 engine weighs about 45 kilograms that of a DTM car only 20 kilograms.