Well, I wouldn't say the ZR1 had its head handed to it. 4 seconds on a 7 min track is a pretty small margin, however the Viper still won. :)
Here's the thread on the viperclub site about the ACR at the ring:
http://forums.viperclub.org/srt10-srt10-coupe-discussions/617667-acr-7-22-ring.html...