It's already hot at 11 a.m. as we pull our 2009 Nissan GT-R into the visitor's parking lot at GM's proving grounds in Arizona. The Japanese supercar looks like a spaceship next to the aging, 1960s-era brick buildings that front the massive desert test facility on the outskirts of Phoenix. Although the few GM employees who see the GT-R barely pay it any attention, we suspect they know why it's here. Somewhere deep inside this test facility there's a 2009 Chevrolet Corvette ZR1 getting prepped for a comparison test, and now the competition has arrived. We make a few calls and sign a few release forms before a Cyber Gray ZR1 emerges from the main gate and pulls up next to the GT-R. The driver gets out, hands us the keys and gives a friendly warning, ""Go fast carefully."" From here on out, it's the King Kong of Corvettes versus the Godzilla of Japan. We'll drive both cars more than 300 miles back to Los Angeles before putting them on a dyno, running our customary round of instrumented tests and wrapping it all up with hot laps on the road course at Streets of Willow.