The manifold advantages of plastic

Engineers from BASF and automotive specialist Mann + Hummel have collaborated on the development of the world’s first plastic active manifold for direct-injection petrol engines. The component has gone into series production on the new Audi A4 2.0 FSI 4V.

With the FSI engines, unlike conventional petrol engines, the fuel is injected directly into the combustion chamber (FSI: Fuel Stratified Injection). This, claim the developers, increases torque and power, lowers fuel consumption, and significantly improves emission data.

The lower and inner parts of the newly developed manifold are made of Ultramid B3WG6, while the upper shell is made of Ultramid B3EG6 Titanium Grey.

BASF claims that the dimensional, thermal and chemical stability of Ultramid make it ideal for this application. It must, for example, be capable of tolerating the high temperature and corrosive chemicals of the exhaust gas during exhaust gas recirculation (EGR).

A further advantage is that the material’s high colour stability under corrosive conditions fulfils Audi’s designers’ special requirements on engine styling without additional painting.

Mann & Hummel’s switching active system consists of two parts. Firstly, a rotary valve drum with a sealing cage controls the length of the intake pipes, and makes for a significant improvement in engine characteristics (torque and power).

Then, the CVTS (Continuous Variable Tumble System) flange controls the air flow; creating a finely distributed, homogeneous fuel-air mixture in the combustion chamber. The Rotary valve drum, sealing cage and parts of the CVTS flange are also made of glass-fibre reinforced Ultramid.

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