Cutting nine seconds off the lap time of a car is huge. It's the difference between running in the dry versus the wet for some cars--and it's also the difference between the 2010 Shelby GT500 and the 2011 version with its new aluminum-block 5.4-liter supercharged V-8.

The video is just about perfect: lots of data readouts, a clear view of the track and driver, no BS music screwing up the sounds of the engine and tires, and a running timer to track the lap. Plus, it's at Virginia International Raceway (VIR)--one of the most fantastic tracks in the country. What are you waiting for? Watch the video!