Additional contributors to the car’s track performance included greater stopping power – the Z/28 features Brembo carbon ceramic brakes capable of 1.5 g in deceleration, and consistent brake feel, lap after lap – and reduced curb weight. The naturally aspirated Z/28 weighs 300 pounds less than the supercharged Camaro ZL1, with changes ranging from lightweight wheels to thinner rear-window glass. In fact, 100 percent of the un-sprung mass (suspension, wheels, tires and brake system) has been changed from the Camaro SS, dramatically enhancing the balance and overall driving feel of the Z/28.
“The Camaro Z/28 is an uncompromising performer that’s bred for the track – and every one of its unique components supports the goal of faster lap times,” said Mark Reuss, executive vice-president, global product development. “It takes the Z/28 back to its racing roots and adds to the strong lineup of Chevrolet performance cars.”
Powertrain
The Camaro Z/28’s 7.0L LS7 engine is rated at an SAE-certified 505 horsepower (376 kW) and 481 lb-ft of torque (652 Nm), it complements the lightweight vehicle components to give the car its enviable 7.6:1 power-to-weight ratio – and deliver the power to accelerate strongly out of corners and achieve high straightaway speeds.
The LS7 was bred on the racetrack, with features designed for the high-rpm environment of the track, including a durable forged-steel crankshaft, lightweight titanium connecting rods and high-flow cylinder heads with lightweight titanium intake valves. It also features a racing-style dry-sump oiling system that helps ensure adequate oil pressure during high-load cornering.
A unique open air box intake system optimizes high-rpm airflow into the engine. It features a reusable K&N conical air filter and delivers the highest airflow performance of any production Camaro filter system. The air cleaner seals around bottom of the hood, reducing the chance recirculated hot air will be drawn into the engine.
The Z/28’s dual-mode exhaust system is engineered to provide high-flow and muscular sound character under aggressive acceleration, while attenuating noise levels in cruising conditions. It actively controls valves that change the flow path of the exhaust. With the valves open, the system produces less back pressure and more power from the engine.
A TREMEC TR6060 six-speed, close-ratio manual transmission backs the LS7 engine. It has a combination of double-cone and triple-cone synchronizers on all gears. Double-cone synchronizers have two friction surfaces to affect gear acceleration and triple-cone synchronizers have three friction surfaces – the greater the friction surface, the easier the transmission is to shift.
The transmission is used with a 5.1-ratio short-throw shifter that provides quicker, more precise-feeling gear changes – similar to ZL1 and SS 1LE models.
Rear axle
Power conveyed through the transmission is distributed to the rear wheels via a high-performance, zero-preload limited-slip differential that enables the driver to apply more power and get through corners faster, by continuously adjusting the torque bias to maximize available traction. It features a concentric helical gear set that generates friction proportional to the input torque and allows continuous torque biasing and differentiation to be managed between the drive wheels (conventional limited-slip differentials use preloaded clutch plates and springs to create a fixed amount of friction that is always present). The axle ratio is 3.91.
Chassis and suspension
The Z/28’s performance focus is maximum cornering, braking and lap times. Comprehensive chassis and suspension changes, including a lower center of gravity, specific stabilizer bars, higher-rate coil springs and other chassis and suspension features have been optimized for the track – enabling more than 1.08 g in lateral acceleration and 1.5 g in deceleration. Racing-bred dampers, tires and carbon ceramic brakes play important roles in not only maximizing performance, but making it more predictable and consistent with every lap.
Wheels, tires and brakes
A major contributor to the lateral performance of the Z/28 is the wheel-and-tire combination, featuring the widest front wheels/tires of any comparable sports coupe. Engineers incorporated a comparatively smaller, 19-inch package, with P305/30/ZR19 tires front and rear – mounted on 19x11-inch front wheels and 19x11.5-inch rear wheels – which contributed to lowering the center of gravity 33mm, for enhanced handling.
Performance Traction Management
Performance Traction Management (PTM) is an advanced system that integrates the chassis mode selection, Traction Control and Active Handling Systems, which are tuned specifically in the Z/28 for optimal road-course performance and consistency. PTM enables the driver to press the accelerator pedal to wide open at the exit of the corner and manages acceleration based on the given vehicle dynamics.