Pontiac Continues Testing GTO.R race car

2/18/2005 - The new Pontiac GTO.R race car, scheduled to debut in Sahlen's Six Hours of The Glen race on June 12 in the Grand American Rolex Sports car series, went through another series of tests recently at the legendary Sebring International Raceway. The car is still undergoing testing and modification to optimize the vehicle for its introduction in the GT Class of the Rolex Series and these latest tests follow similar successful running at the Homestead-Miami Speedway last month.

"We're totally happy with the durability of the production engine installed in the car - we even still have the production camshaft and valve train," said Lynn Bishop, engineering manager at Pratt & Miller, a partner corporation in the GTO.R project. "The performance and durability seem to be there so we're just continuing to develop the production engine management system."

The car is allowed within the series regulations a modified camshaft, valve train components and crankshaft, but Pontiac will only upgrade if necessary.

"Even though the rules allow us to use aftermarket cams, valves and springs, we may not need them," Bishop stated. "If the car continues to perform suitably, we'll stick with the production pieces for the foreseeable future."

The production-based GTO.R uses the new 6.0-liter LS2 engine with modifications to the exhaust manifolds with the addition of a dry-sump oil system. Its output has been bumped to a Grand American-mandated 450 horsepower from the road car's 400, and most body panels are composite copies of the steel originals (with the exception of fender flares to fit wider wheels) fixed to a tube-frame chassis. Front and rear fascias are production parts as well as the mirrors, lamps and grilles. Brakes, suspension and other running gear consist of aftermarket parts.

GM has replaced the aftermarket powertrain control module (PCM) it used at Homestead with a remapped production unit.

"Everything inside the engine is a production part except for the rod bolts," said Steve Wesoloski, lead engineer of the GTO.R. "We've now gone to a production GM PCM which has been reprogrammed for racing, but it's still out of a production car. It's all helping us inch up towards the lap times we're looking for, and Jan (Magnussen) is getting comfortable with the car."

A second GTO.R is now under construction and will begin competing shortly after the first race car's premiere. An affordable, race-winning package will be developed from experience gained during the 2005 season and GTO.R race cars will be offered for sale to independent teams for campaigning in 2006. GM Racing will provide comprehensive technical support to those teams.

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