We found a problem in the computation model and fixed it. In addition we made some changes to the front, diffuser and the rear wing of the car. Some small changes were made to other parts as well.
The rear wing was changed to a multi-profile design, the profile was also changed and the angle of attack modified. The angle of attack is also variable. With these changes the entire wing works optimally and produces more downforce.
The newest calculation converged to 3270N downforce and 1022N drag.
Compared to Le Mans prototypes from the 90's these values are slightly worse, but the stock car frame we are using is limiting the design. There should be some room for improvement though.
We've used about 40 hours so far designing the CAD model, and about 10 hours running the CFD calculations.