The Dodge Viper SRT10 ACR is officially the world's fastest production
car at the track.
Here are the OFFICIAL fastest times.
I don't think the official times has the FASTEST PRODUCTION CAR ON THE
TRACK on the List.
The Mighty GTR Spec-V has already been rumored to have done the Ring
in 7:15.
The Spec-V had at 3rd place starting position and was still able to
win by several seconds.
People thought that the Spec-V would need to gain at least 47 bhp and
lose 250lbs to become the world's fastest production car on a track,
but the GTR Spec-V only gained 5 bhp and lost 132lbs and got a stiffer
suspension, better brakes, etc and is the defacto fastest production
car in the world on a track. I think the ONLY car I can see beating
the GTR Spec-V would be the Koenigsegg CCXR which I'm not sure is even
considered a production car with a total production run of 6 vehicles.
If it is a production car, then that's the only thing that may beat
the Spec-V at the ring.

7:22.1 2009 Dodge Viper SRT-10 ACR

7:24.3 Maserati MC12

7:24.7 Pagani Zonda F Clubsport

7:25.3 Ferrari Enzo

7:26.0 2010 Nissan GTR

7:26.4 2009 Chevrolet Corvette C6 ZR1

7:26.70 2010 Nissan GT-R

7:27.82 Pagani Zonda F Clubsport

7:28.71 Porsche Carrera GT

7:29.03 2009 Nissan GT-R