The R35 Nissan GT-R has a great cD (Coefficient of Drag) from the factory, but we saw one area we could improve upon. The tunnel area of the R35 is left wide open; and by covering this large area, we are able to further reduce the drag generated by the vehicle's underbody. In some cases where the vehicle is raked, we were able to realize an increase in downforce.
Using ANSYS Adjoint solver and CFD, we were able to reduce the cD by 10 points, or 0.010. The tunnel area of a vehicle is a source of increased drag; by covering this with a purposefully sculpted piece of carbon, we can reduce the drag of the vehicle.
These units are produced from pre-preg carbon fiber off of a machined billet mold. No expense was spared in the production of these tunnel covers. Included in the cover are a low drag evacuation duct for heat evacuation, and two low drag NACA ducts to aid in cooling the transmission.