Since Stoptech specializes in brakes, that's where we'll begin. They wanted to use a system that would decrease stopping distances, reduce fade, and also reduce weight. By using rotors forged from aluminum, they did just that. Although the front rotors are a Domino's Large-sized 15" (14" rear) they still managed to save the M3 17.6 pounds. The real halting power comes from the 6-piston front calipers which grab those disks like Kanye West does someone else's microfone.
What that all means for the M3 is braking later and for less time, which equals more time on the gas and thus lower lap times. A + B + C=winning, and winning is good. Horsepower is certainly more fun, but if you want a faster lap, braking is equally important. Imprisoning the slotted rotors are a set of APP wheels that, despite being 19", weigh 3.3lbs less per wheel. Those two upgrades reduce unsprung weight and rotating mass, leaving improved acceleration as a nice side effect.
But if you're building a car, you won't leave faster acceleration solely up to the reduction of weight; you can't. It may not be illegal, but it goes against man, nature, and god. So Stoptech sent the car to APP, who -and they won't tell us how - coaxed 30 more horsepower and 30 more torques from the V8, for a total of 450hp/325lb ft. It may have had something to do with the new titanium exhaust, which is 50 lbs lighter than the stock system. Perhaps BMW soaked the exhaust in cement before they bolted it on? Capping off the track-friendly gift bag is a set of Club Sport coilovers by KW, and very nicely done silver Vinyl Wrap.