Bosch Mahle Turbo Systems (BMTS) has developed a specially designed turbocharger for the 1.5-litre BMW three-cylinder diesel engine. This is a particularly performance-oriented exhaust turbocharger with variable turbine geometry (VTG), which is also extremely efficient due to its turbine and compressor design and therefore reduces fuel consumption.

The new turbo is a prime example of how BMTS is helping car manufacturers to fulfil the requirements for engine efficiency and performance as the trend to ‘downsize’ engines continues. The optimised blade design of the VTG, allied with a low-friction bearing, lend the engine spontaneous response behaviour, especially in the low speed range, thereby delivering a broad torque plateau. Thanks to the electrical control of the guide vanes, a significantly lower hysteresis is achieved and faster adjustment made possible.

The demands on the acoustic and dynamic behaviour of the turbocharger are especially high in the premium segment, which is why the BMTS VTG turbocharger is equipped with particularly low-noise, weight-optimised actuating elements with plastic bushings in the coupling rod, a floating bush bearing with acoustic package and a milled impeller, for less pulsation noise.

At St. Michael in Austria, BMTS has set up state-of-the-art production facilities in order to implement high technology standards in large-scale production, while maintaining its commitment to quality. Its end-of-line testing, which BMW describes as “an outstanding improvement in the turbocharger assembly” allows the manufacturing parameters and balancing values of each turbocharger to be checked in a fully automated process to document the highest level of quality and precision.

This has established the high quality of the finished BMTS turbocharger, which in BMW’s so-called misuse tests, survived all the tests, which usually lead to the destruction of the impeller, completely unscathed.

Together with BMW, BMTS has also developed a new packaging concept for the finished turbochargers. Instead of sealing the openings of the turbocharger, as was done previously, the exhaust gas turbocharger is placed on a support and completely enclosed with a plastic casing to protect it against contamination and make it easier to handle.