Image: Nick Holland
Finally, the 919 sees a heavily revised rear deck configuration. The rear deck sees to inner extensions to the rear wheel pods, with a rear Gurney flap lining them. This is 100% a down-force generator. The extended pods with the gurney will draw low pressure towards it which will be used to push the gurney into the road.
The rear wing upper main plane was also updated come to the 6H. There was a much higher angle of attack to help produce more down-force but with more drag.
Audi
The R18 saw two updates at the Nurburgring: the rear deck and the rear wing. To remain on par with Porsche, Audi seems to have to used its low drag nose, which sees less surface area to help get air
under the chassis as well as reduce drag on top of it. This was used at Nurburgring and proved a good move by Audi, but still it wasn’t enough to beat its German rivals.
At the back of the car, Audi had put up the angle of attack of the rear wing main planes. By this you can reduce the lift on the main plane, and use it’s as a down-force benefit. This is
what an aeroplane does,
but invert it, to create
lift, so it can take off.
The higher your angle of
attack the more lift you
generate until the point
of separation which is
called wing stall. When
you stall, flow separates
and the pressure becomes turbulent, which is bad for down-
force, as you are not
getting the performance
out of the wing and make
life very nervous for
drivers!
Lastly, Audi had mini cut out section on the rear deck. It's unknown what this does, but looks to be a way to slim the drag levels that little bit more. There will be less drag from the cars gurney too as its stepped section will reduce drag as well as down-force.
Toyota
As far as I’m aware Toyota only put up the angle of attack on the rear wing, which is pretty standard stuff. But as we know no, Toyota has stopped development of its 2015 car, and will now concentrate on its 2016 challenger, which will have no V8 and heavily revised hybrid unit on board, to help it challenge its German rivals.