SHEAR VALVE 911 RSR ST TYPE 46 MM PAIR FOR ENGINE OVER 3.0 LITRES for Porsche

RSR slide valve injection system with 41, 43 and 46 mm diameter

Complete slide valve injection system for the Porsche 911 RSR in the diameters 41, 43 and 46 mm. Slide valve injection systems have been used in Porsche racing vehicles since the 1960s in order to achieve maximum engine performance. The main advantage of a slide valve injection system is that when the slide valve is fully open, the maximum flow values can be achieved with the minimum opening cross-section. In contrast to a throttle valve system, neither a vertical flap nor a shaft nor screws, which on the one hand reduce the usable flow cross-section and on the other hand can introduce undesired turbulence into the gas column, interfere here. This in turn has the advantage of being able to achieve higher flow values despite the reduced cross-section, which can always be converted directly into power.

Furthermore, the mass of the gas column is reduced by the smaller cross section, which enables an additional increase in performance due to the vibration behavior of the gas column. Flow measurements in our house have shown a flow value reduction of less than 1%. The intake funnels supplied in each case always have exactly the right cross-section and, thanks to the extremely high manufacturing quality, there are no disturbing edges or transitions in the assembled state.

The only disadvantage that a slide valve injection system had for a long time could be completely eliminated through the complex construction and processing of this system. For a long time, this was the high "breakaway torque" from idling into the partial load range, which is a thing of the past with this system. When idling, the high negative pressure below the slide plates led to an increased need for force to open the slide, which suddenly decreases as soon as the negative pressure breaks down when the slide is opened. Our systems prevent this completely by guiding the slide plate in hardened industrial needle bearings, which are constructed with such high precision that the high-strength slide plates slide almost frictionlessly with no contact in the housing.

The housing, on the other hand, was manufactured using the aluminum sand-casting process of that time, and was secured against warping and jamming despite the various temperature influences thanks to a complex heat treatment. In addition, the surfaces of the raceways of the needle roller bearings are resistant to wear in a further galvanic hardening process and therefore maintenance-free.