2001-2005 Audi R8

Images copyright Juha Kivekas, Phil CK, Olivier Trocherie, and Audi Sport Press
Text copyright Michael J. Fuller

The 2002 R8's most radical difference over '01 chassis were the deep rear wing endplates/fins.  The 'fins' skirted around the restrictive ACO endplate ruling by not actually attaching to the wing end fences, having a minor 1-2 mm gap.  Note the wing shape of the horizontal plate that the endplate mounts to.  Since the plate is above the rear wheel centerline, its section is free. 
Note how small the gap really is...the benefits of deep endplates have been discussed before.
This shot gives a visual idea of how the endplate effects the airflow underneath the wing.
The R8's rear wing architecture was revised for the 2004 season to comply with the regulation changes mandated by the ACO for Le Mans and the Le Mans Endurance Series (the changes did not effect R8s entered in the American Le Mans Series).  The changes stipulated that chassis built prior to 2004 had to reduce the span of their rear wing to 1800 mm (from around 2000 mm).   The purpose was to bring older cars in line with the performance of new for '04 prototypes.  Audi simply removed approximately 200 mm (100 mm either side) of the wing's span.  Instead of moving the deep endplate inboard (and dealing with further redesign and new-parts manufacture), Audi decided to maintain the outboard position of the deep endplates but attached them to the shortened span via carbon extensions.
2003/2004 ALMS:
2004 LMES/Le Mans:
A close up of the box extensions showing the relative simplicity of the idea.  With carbon extensions bridging the gap one could ask when is a wing not a wing?  Though it must be pointed out that the air flow is anything but parallel at that point of the endplate and therefore one could argue that the extensions are a drag inducer and not necessarily very efficient downforce generators.  But maybe the R8 has drag to give away?

ęCopyright 2004, Michael J. Fuller