Racing to tech transfer

Lessons learned on the track today benefit next-generation production cars. A side-by-side comparison of the C6-R and 2006 Z06. The slightly wider C6-R uses a rear wing and front splitter to produce down force. These factors raise drag coefficient to about 0.4 compared to roughly 0.29 for the Z06. Race-car engineering firm Pratt & Miller Engineering, New Hudson, Mich., designs and fabricates the Corvette C6-R and Cadillac CTS-V race cars. An LS7 7.0-liter small block. Fitting the 104.8-mm-diameter "Siamese" bores was an engineering challenge. Earlier 7.0-liter (427 cu in.) engines were much larger "big blocks." Racing blocks are precision bored and have no cylinder liners, while production versions use precision-ground liners. One reason is expected lifetime. Race motors need only last 24 hr maximum, while production engines generally go 100,000 miles or more between overhauls. A peek under the hood of a C6-R race car reveals a carbon-fiber intake box fed by two ducts. Each duct flange contains a 31.5-mmdiameter restrictor plate. The plates limit airflow to the 7.0-liter engine and cap power output at about 590 hp. Race rules key restrictor size to car weight; heavier cars get bigger restrictor plates. The engine is capable of about 800 hp with the plates removed. Production LS7 engines get several "go-fast" goodies from the C5-R racing program including a forged-steel crankshaft, titanium connecting rods, forged 11:1 compression flat-top pistons, titanium intake valves, sodium-filled exhaust valves, titanium pushrods and valve springs, CNC-ported heads, and dry-sump oiling. C6-R Corvettes compete in the American Le Mans Series against marques including the Maserati MC12, Saleen S7R, Aston Martin DB9 and DBR9, and Dodge Viper. They also run the 24 hours of Le Mans Championship The year 1963 saw the first road-race/ production Chevrolet Corvette, the Z06, a car which no doubt helped popularize the phrase, "What wins on Sunday sells on Monday." Chevy reintroduced the Z06 in 2000, a year after GM Racing began campaigning its C5-R Corvette race cars. Since then, factory-backed Corvette racing has gained traction with car buyers. So much, in fact, that GM at the end of this year will leave IndyCar racing to focus