I don’t know about you, but this video just blew my mind. If you haven’t watched it already — spoiler alert! — Chevrolet had issues with the new Z/28 braking and cornering so hard, it would literally spin the tires around the rims. Originally, the development team though the rotation was only occurring by a few degrees, but after marking the tire’s location on the wheel, they found it rotated nearly 360 degrees while lapping the test track.
To solve the issue, Chevrolet tried several ways of locking the tire’s bead to the wheel, including coating the inner wheels with abrasive paint. Nothing stopped the problem, so the team took a media blaster to the inside of the wheel. The tiny grains of sand ate away at the smooth surface and created a slightly pitted, coarse surface for the Pirelli P Zero Trofeo R tires to grip. It’s an ingenious solution to a hidden problem that negatively affects lap times and braking performance.
When the top-dog Camaro Z/28 hits dealers this spring, it will arrive with 505 horsepower and 481 pound-feet of torque coming from its naturally-aspirated 7.0-liter, LS7 V-8. Through the Camaro ZL1 makes more power at 580 horses and 556 pound-feet, the Z/28 is a faster track car, thanks in large part to its reduction in weight. Heavy use of carbon fiber and lightweight glass, along with a lack of many creature comforts, the Z/28 drops some 300 pounds from the ZL1’s curb weight.
Video and more about the Chevrolet Camaro Z/28 after the jump.
The Camaro Z/28 will fill the top slot in the Camaro lineup with the ZL1, SS, and base cars trickling down. Built specifically as a track car, the Z/28 forgoes numerous creature comforts such as standard air conditioning, stereo system, and sound deadening to create the lightest Camaro possible. Compared to the 4,120-pound ZL1, the Z/28 is a full 300 pounds lighter.
Power comes from an LS7 — similar to what the Corvette C6 Z06 used — making 505 horsepower and 481 pound-feet of torque from its 7.0-liters of naturally aspirated masculinity. Carbon-ceramic rotors are clamped by Brembo calipers to bring the car to a stop. Unique aerodynamic parts add extra downforce to the car as it speeds along at a top speed of around 170 mph.
Gallery Chevrolet Camaro Z/28
While running fast laps at several of the country’s most challenging tracks, Camaro Z/28 engineers noticed the tires were providing so much traction and the brakes so much stopping force that the wheels rotated inside the tire – an unexpected challenge that required fast thinking.
“We were told to build a fast car – period,” said Mark Stielow, Camaro Z/28 program manager and pro-touring expert. “We knew on Day One we’d need to bring some of the best suppliers onboard to make it happen.”
The suppliers included Pirelli and its P Zero™ Trofeo R tires and Brembo for carbon-ceramic brake rotors. The Trofeo R tires have a track-oriented tread design and compound that, together with the carbon-ceramic rotors, help the Z/28 achieve up to 1.5 g in deceleration force.
It was a perfect combination, but engineers quickly found that when the Z/28’s capability was tested, the wheels were rotating – slipping – inside the tires. They sought the root of the problem by marking one of the Pirelli P Zero™ Trofeo R tires at the beginning of a lap with a chalk line relative to the valve stem on the wheel. At the end of the lap, they recorded where the chalk line ended up and noticed the tire had rotated at least a full 360 degrees from where they started.
Racers use an abrasive paint around the bead of the wheel, where the tire meets the rim, to combat the problem on race cars. The Z/28’s engineers tried it, but it wasn’t strong enough to prevent the slippage, so other approaches were tried. Finally, they tried media blasting, which involves shooting a gritty material through an air gun at the wheel’s surface, adding texture to the paint for the tire to grip.
“Media-blasting the wheel created an extremely aggressive grit on the rim, which finally got the tire to hold,” said Stielow.
Along with the tires and brakes, some of the tire slip can also be attributed to the 7.0L LS7 engine helping spin the wheels with an SAE-certified 505 horsepower (376 kW) and 481 lb-ft of torque (652 Nm). While going around corners, the helical-gear limited-slip rear differential also sends power to the wheels so well that differences in tire slip can be observed from side to side on the rear axle.
The 2014 Camaro Z/28 arrives in dealerships this spring.