Dave Hill, the former Corvette chief engineer, said the following in the April 2006 issue of Corvette Magazine:
"We had titanium rods on the street [for the new Z06], but they didn't have them validated for racing. They'll be validated for 24-hour races by the time we go to Le Mans next year, though."
http://www.corvette-mag.com/
Does anyone know how much the 590 hp LS7-R weighs?
The following is from the January 2006 issue of Sports Car International on page 35:
"The net result is a fully trimmed engine that weighs 458 pounds, only 10 more than the 6.0-liter LS2."
Also, BMW's M5 Product Information Guide says that the 5.0 liter 500 hp (SAE net) V-10 weighs 240 kg/529 lbs.