[V8] V8 brake upgrades

[NIck Miller]

So, a quick update, got the caliper and compared it and the pads to the UFO
caliper I have as a spare here.

The Merc has 35mm and 38mm pistons x2, one of each on each side.  This gives
a total of 73mm of piston per side, vs the Ufo calipers single 58mm piston.

The Merc's pad is 6.5cm by 10.5 cm, for a total area of 68.25cm, and this is
pretty close, it stays almost fully consistent at 6.5cm through the whole
thing.

http://smg.photobucket.com/albums/v215/Chance901/?action=view&current=100_0788.jpg
http://smg.photobucket.com/albums/v215/Chance901/?action=view&current=100_0781.jpg
http://smg.photobucket.com/albums/v215/Chance901/?action=view&current=100_0785.jpg