GM PERFORMANCE DIVISION GOES TO EXTREMES WITH BONNEVILLE HHR

WENDOVER, Utah - What happens when GM Performance Division combines heritage with horsepower? The result is the Bonneville HHR - a radical race car with retro styling and rocketship speed.

The Bonneville bug has bitten GM Performance Division engineers hard. After two forays to the famed Salt Flats with production-based race cars, they are returning in 2005 with their most extreme machine yet - a chopped and stretched Chevrolet HHR powered by a 1,000-horsepower turbocharged Ecotec engine. The HHR's sculptured body panels cloak a fabricated tubular steel frame that mounts the engine midship and puts the driver in the back seat.

Chevy's new 2006 HHR pays homage to the 1949 Suburban - the original utility vehicle. The production HHR is designed to haul everything from groceries to surfboards in style. After its transformation by GM Performance Division and So-Cal Speed Shop, the Bonneville HHR racer is ready to overhaul the G/BFCC (G Class/Blown Fuel Competition Coupe) speed record.

Why an HHR for the salt? Al Oppenheiser, director of Concept Vehicle Engineering, explained: "The message from GM's leadership was clear - 'Every employee needs to do what they can to communicate the energy and excitement of the great new products we're launching, such as the HHR.' At the GM Performance Division, we felt that there was no better way to contribute to the excitement of the HHR launch than to build an HHR race car that could shatter the world speed record in the very competitive G/Blown Fuel Competition Coupe class.

"The grassroots nature of Bonneville reaches audiences far and wide, and the GM Performance Division continues to build momentum each year with our presence," Oppenheiser added. "A new speed record for the HHR would be a great contribution from our team to support the GM leadership's message."

GM Performance Division is aiming high at Bonneville. The G/Blown Fuel Competition Coupe record stands at 226.835 mph, a lofty mark established 15 years ago.

"The Bonneville HHR project grew out of our previous experience on the Salt Flats," said GM Performance Division engineer Mark Dickens. "We pushed the limits of front-wheel drive with the production-based Saturn Ion Red Line and Cobalt SS. Now we're taking a different direction with a tube-framed HHR that's been converted to rear-wheel drive to optimize traction on the salt.

"We're running in a very tough class," he noted. "We have to execute perfectly to get the record. It will be a real test for us, but we're ready for it."

The Bonneville HHR began life on a GM assembly line in Ramos Arizpe, Mexico. The production four-door steel body was then chopped seven inches and its wheelbase stretched four inches by the craftsmen at So-Cal Speed Shop in Pomona, Calif. The shop also fabricated the drag race-inspired tubular chassis from high-strength chrome moly steel tubing.

The Ecotec engine in a production HHR is mounted transversely and drives the front wheels; in the Bonneville version, the engine is mounted longitudinally and powers the rear wheels. Occupying the space once reserved for the front seats, the Bonneville HHR's mid-mounted Ecotec delivers its prodigious torque via an air-shifted five-speed racing transmission and a quick-change rear end.

"The HHR's Ecotec is essentially identical to the engine we use in the Cobalt SS race car at Bonneville," Dickens explained. "It's turbocharged and intercooled, it burns methanol fuel, and it produces 1,000 horsepower at full boost. The ultimate speed of our front-wheel drive race cars is somewhat limited by the gear ratios that are available for their four-speed automatic transmissions. With the HHR's 5-speed gearbox and quick-change rear end we have the ability to optimize the gear ratios. The racing transmission allows us to change individual ratios to optimize the rpm drop during gear changes based on the engine's power curve. We can also optimize top speed for the conditions at Bonneville by changing the rear end's final drive ratio."

While the HHR's styling has retro elements, its aerodynamic attributes are state-of-the-art.

"We worked with the production HHR aerodynamicist and our in-house aerodynamic experts at GM," Dickens said. "All of the Bonneville HHR's aero development was done at the GM Aerodynamic Laboratory in Warren, Mich., by people who understood our requirements for high-speed stability and traction.

"So-Cal Speed Shop brought its own flair to this project." Dickens continued. "Our engineers put together a list of items that would optimize drag and downforce, and the So-Cal crew members incorporated their specifications into a mold for the fiberglass front end. Working with an organization like So-Cal Speed Shop was rewarding because they are performance-minded stylists, and they produced a front end that pleased both the designers and the engineers."

"It's always a challenge chopping a modern vehicle," said So-Cal Speed Shop President Pete Chapouris. "The HHR's body panels are galvanized steel, and we had to chop four doors and fabricate a new tailgate to house twin parachutes. The roof incorporates NASCAR-style flaps and side rails to prevent the car from becoming airborne and to help slow it down should it spin. We installed a Funny Car-style escape hatch in the roof as an additional safety feature."

So-Cal Speed Shop fabricators Robin "Silky" Silk and Paul Rivera constructed the Bonneville HHR's tubular chassis. Inspired by the Pro Mod chassis used in drag racing, the HHR framework is a double-rail design. The engine can be easily removed for service by sliding it forward on the upper chassis rails. The front suspension incorporates lightweight MacPherson struts and the rear suspension is a four-link system with coil-over shock absorbers.

"GM Performance Division supplied the basic design points - the wheelbase, the track width, the driver location and the optimum weight distribution," Dickens said. "Then So-Cal Speed Shop's fabricators connected the dots."

GM Performance Division engineer Jim Minneker will make the run for the record in the HHR. An accomplished road racer, Minneker got his first taste of the Bonneville salt in October 2003 when he piloted GM Performance Division's Saturn Ion Red Line coupe to a 212.684 mph record in the G/Blown Fuel Altered Coupe class.

"We love to be part of Speed Week," Minneker said. "GM Performance Division recognizes and appreciates the hot rod tradition at Bonneville. It's distinctly American grassroots racing, and that's why we're there."

Many unusual vehicles will race across the salt during Speed Week, but none has the unique combination of horsepower and heritage that GM Performance Division's HHR brings to Bonneville.

General Motors Corp. (NYSE: GM), the world's largest automaker, has been the global industry sales leader since 1931. Founded in 1908, GM today employs about 317,000 people around the world. It has manufacturing operations in 32 countries and its vehicles are sold in 200 countries. In 2004, GM sold nearly 9 million cars and trucks globally, up 4 percent and the second-highest total in the company's history. GM's global headquarters are at the GM Renaissance Center in Detroit. More information on GM can be found at www.gm.com.

Bonneville HHR Specifications