I've had a number of people ask me this, and I've tried to find the answer and can't.  I figured if anyone knew the actual reason, it would be someone here.

I don't know the correct answer, so this is just my personal opinion. The Corvette is designed and built to compete against the best sports cars in the world. Just watch any Le Mans race an you will see the Corvette running with and ahead of the likes of Aston Martin, Audi, Peugeot, Porsche, Viper, etc.

I enjoy NASCAR but all we're seeing is a field of cars that are basically identical, other than the drivers. Gone are the days of what I considered real racing when the manufactures sponsored the cars.

 I think it has something to do with  wheelbase and width dimensions,or it may just  put all the others to shame,,rd

Consider the origins of the sport. It stemmed from Prohibition days, when souped-up Detroit cars were used by 'moonshiners' to outrun Federal revenue agents. Later, the cars were deliberately chosen to represent models that the 'average Joe' could actually afford--and might drive. The old auto industry saying about this was 'win on Sunday, sell on Monday'--meaning if they could get NASCAR fans excited by a Chevy/Ford/Dodge etc. winning on the weekend, they had a better shot at selling the "same" model to them at the dealership (even though the race cars were significantly modified from factory production versions).

Nowdays, of course, the cars bear no resemblance at all to production models, except for the basic body shape.

Gimme the factory Corvette Racing Team, a brace of C6-R's, and an American LeMans Series road course any day. Too bad the Aston Martin factory team beat them at the 24 Hours of LeMans this past weekend--but they'll be back in the winner's circle soon!

I thought all the cars were just replicas anyway. Built from the ground up.

Same reason you've never seen a Musturd, Camaro/Fireturd, etc run Lascar...the series was intended for sedans.

Damn shame about the C6R team luck last weekend.  One team went out early with a driveshaft issue, the others, thanks to ALMS and the French who make the rules for the 24hrs Du Mans have seen to it with weight additions that the vettes aren't as competitive as in the past.

Give the engineers a year or so and we'll be back on top once again!