We are working hard to get the D1PPS together and every day more parts are completed. The bodywork is now painted and ready for graphics.
We are machining additional suspension parts, assembling the differentials (Quaife internals in our own custom housings), our proprietary torque splitter for the AWD system, and so on. Turbo parts are here as well and we are finishing the installation.
In the meantime CFD runs continue at night. Here’s another illustration of why it’s important. Below are two pictures of airflow under the rear wing. Note in particular the different amount of blue (low pressure) under the wing, and the numbers – a nine pound difference in downforce. Only one small thing was changed between the two, and it’s nowhere near the wing…
The change was to remove a 1/2″ tall gurney at the leading edge of the cockpit, in front of the driver. In the pictures below you can see how that affects airflow through the cockpit, and more importantly behind it (look closely at the turbulence behind the cockpit). Removal of gurney improves wing efficiency (14 lb downforce gain), which in turn improves underbody efficiency (another 10 lbs gained), but increases lift on the body by 15 lbs. So, a net 9 lb gain in downforce.
Aerodynamics is a big jigsaw puzzle with a multitude of pieces, many of which interact in ways that aren’t necessarily obvious. Knowing what effect each piece has on the others and on the overall system is key to being able to optimize the car, and quickly tune it in testing and for the race.