As per the article cited..

"At 60 mph, the Porsche's 4.3-second time is only 0.2 second slower than the Vette's, but at 150, the gap is 3.5 seconds.

The 911, therefore, needed a major handling advantage to outrun the Vette at GingerMan. No such trump card arose. Like most recent 911s, this one predominantly understeers, so in GingerMan's long corners, we had to wait seemingly forever to put the power down and accelerate out of the turns. The 911's best lap time of 1:37.95 was 2.3 seconds slower than the Vette's. That's an eternity in road racing."

Thats pretty good for numb

You can dial out a lot of the "numb" for relatively little cost compared to modding a 997. But even "numb" the non Z06 standard vette just crushes a 997S on a track and that is where sports cars go.

I have my suggestions for Porsche, but they are too stubborn to listen.