2006-2008 Audi R10

Images copyright Pete Lyons, Pat Michl, Photos @ Vector Trust and Michael J. Fuller
Text copyright Michael J. Fuller

Sebring scrutineering 2006 It is amazing how low the upper A-arm mounts to the tub, the angle bit inboard being the pushrod.  The profile of the fender itself is very similar to the R8 when viewed from the side.  Note the bulges on the fender for tire clearance.  The bulges are a somewhat perplexing detail and seem to suggest a late change in tire diameter.  We know from the press material that this is an area of difference to the R8, though incorrectly stated as a difference in width.  It is actually a difference in diameter--650 mm diameter for the R8, 680 mm diameter for the R10's fronts.  In actuality the R8's fronts are wider comparatively, 13.5" vs. the R10's 13.0", though the R10's are taller as noted.
The appearance of a parting line also lends credence to this thought (a later change in front tire dimension for R10).  It would be easier to modify a section of the existing fender pattern than resurface (re-CAD) and re-cut the entire pattern.  And the entire fender would have to be resurfaced in order to integrate the bulges into the existing surfaces. 

Certainly the initial thought is that the fender was reduced in size as much as possible as viewed from the front in order to reduce it's frontal projection.  But surely this was being done anyway?  Additionally, in frontal projection the bulges are still viewable making any frontal area reduction academic.

Sebring 2006
Sebring 2006The brake ducts are that in name only.  The single seater nature of the brake cooling is very evident when the bodywork comes off (below).

Sebring 2006The air intake for the brakes matches up to the duct in the bodywork (with appropriate room for wheel movement).  The brake duct backing plate actually overlaps the tire (not residing within the circumference of the wheel) and has an extension where the duct proper is.  This extension may act to reduce the amount of foreign object ingestion as the wheel travels throughout its steering lock.
Sebring 2006The brakes also have an outboard backing plate that completely masks the disc.  The entire brake ducting system is driven by desires to improve brake cooling as well as to eke out aerodynamic gains through reducing drag and gaining downforce.  Contemporary high temperature resin systems make this a reality.  The shielding is so close in proximity to the very hot carbon brake that in order to survive (much less through an endurance race length of 12 to 24 hours--we're not talking Grand Prix race lengths!) it must be made of resilient stuff!
Sebring 2006Though the result of the shrouded brake discs is that brake glow is no longer visible on the R10.
Sebring 2006As on the Audi R8, the R10's outboard plan view fender profile is off set from the inboard surface creating a channel which allows for airflow extraction from the wheel well.
Sebring 2006The wheel well exit panel forms a rules compliance function masking mechanical parts of the car as seen from the side.
Sebring 2006Looking up into the diffuser/wheel well exit.  In the forward slot you can see up into the wheel well proper (yellow Kevlar wheel well lining), aft you can just see the trailing edge of the diffuser.  From this vantage point you can also see the lower A-arm of the front suspension and its forward and rearward pickups on the tub.
Petie Le Mans 2007Towards the end of 2007 a red vertical lip appeared in the exit of the forward front diffuser exit.  Subsequently this was painted black (below, Sebring '08) making it a little harder to see.  As to its function, best speculation is that it further helps extract air from the front fender valley/diffuser.  And this makes sense if you think of the lip as a gurney creating a low pressure area on its outboard surface. 
Sebring 2008

ęCopyright 2008, Michael J. Fuller