The transmission housing for the Porsche 918 Spyder was completely newly developed due to the modified screw connections to the combustion engine, a new unit mount and the special aerodynamics requirements in the underbody area. The control hydraulics was moved from bottom to top in the front part of the housing. The control hydraulics is located in an additional oil pan in order to avoid disturbing air inclusions in the oil supply for the hydraulic system.
The new, additional oil pump with oil filter and oil/water heat exchanger is located in the rear housing area. Due to the fact that the contour of the transmission housing rises to the rear, it was possible to also shape the underbody panelling upwards at the rear of the body, thereby significantly optimizing air flow to the rear diffusor.
The complete undertray of the Carrera GT is made of CFRP and is secured with a total of 128 screws to the chassis. The undertray comprises three large pieces, covering the front axle, the rear axles with the complete drive unit, and the lower part of the monocoque. The main purpose of the undertray is for vehicle aerodynamics.
The undertray in the rear area has additional vertical air guides, called “Fences”, attached to it. The center undertray, by the sills, under 4 removable plastic covers has four recesses for the vehicle hoist plates.
In addition, by selecting a particular undertray form, the downforce behavior in the respective area is improved. This is particularly clear in the rear part of the undertray. This area is structured as a diffuser (air channel) and makes a significant contribution to the downforce on the rear axle.
