Found this article interesting:
http://www.automobilemag.com/reviews/coupes/0206_ford_mustang_svt_cobra/index.html
The flywheel, conversely, switches from iron to aluminum for a sizable reduction in both weight and inertia. SVT claims that change alone shaves 0.2 second off both the 0-to-60-mph and quarter-mile times, because it allows the engine to rev so much quicker. You can feel the difference the first time you bury the throttle.
http://www.automobilemag.com/reviews/coupes/0206_ford_mustang_svt_cobra/index.html