Everyone saying 7:18-7:25 are crazy. That is Corvette ZR1 (w/ Sport Cup tires) and Dodge Viper ACR territory. The Camaro Z/28 will likely have 100+ less horsepower and weigh ~300 lbs more than the ZR1 and ACR Viper. What makes you think it will run those lap times?
I think the Z/28 will run 7:33.
2011 Summit White Camaro 1SS/RS
-6.2 LS3, TR6060, 3.45, G80
2004 Black Silverado 1500 2WD Regular Cab, Short Bed
-5.3 LM7, 4L60E, 3.42, G80