In addition to receiving different gear ratios from the SS version (M10), the ZL1 version (MG9) comes with an air-to-liquid cooler and is 30-percent stronger. The output shaft, rear housing, additional roller bearing, and triple synchros highlight those improvements. The 1LE Handling Package equipped SS models with the smoother shifting MM6, as did the Z/28, which has the same ratios as the MG9 and many of the same improvements.
Connecting the Camaro’s transmission to the rest of the drivetrain is a two-piece driveshaft with rubber couplers that are extremely effective at isolating vibration and noise. The rear-end housing on the LS, LT, SS, and Z/28 is aluminum with an 8.5-inch ring gear. The automatic-equipped SS, manual V-6, and most automatic V-6s came with 3.27-ratio gears (2LT had 2.92). Manual-equipped SSs had 3.45; the ultra high-performance 1LE and Z/28 had 3.91 gears.
All models came with limited-slip differentials. But the Z/28 uses a unique, zero-preload diff with a concentric helical gear set in lieu of traditional clutch plates and springs. This design allows for continuous torque biasing, generating “friction proportional to the input torque.” This is particularly useful at a corner exit, which helped make the Z/28 one of the fastest production cars on the road course. Complementing this track-worthy diff is a specially designed cooler with an integral heat exchanger (inside the housing), which effectively removes more than 100 degrees from the diff fluid. All CV axles have a 30-mm diameter on the driver’s side and 40 mm on the passenger’s side to reduce wheel hop, though the 1LE and Z/28 version has a much beefier CV joint.
As the most powerful in the Camaro lineup, the ZL1 necessarily has the strongest rear end. The ring gear measures a whopping 9.84 inches, and the housing is made of cast iron. The manual trans version comes with 3.73 gears; the automatic has 3.27s. A heavy-duty differential and stacked plate cooler are also capable of providing 100 degrees of relief. The axles, though, are by far the most impressive of the bunch. Measuring 60.5 mm on the passenger’s side and 33.25 mm on the driver’s side, the axles look like baseball bats. For the CV joints, the engineers attempted to pirate some from a turbo diesel 4 × 4. But even those weren’t strong enough, so they started from scratch. One engineer told me that this rear end is as strong as they know how to make. Given the challenges involved with an independent rear suspension, that is saying something.
The basic design and components of the fifth-generation Camaro’s fully independent suspension carry over to all models. The front suspension uses a “multilink strut” and dual-ball joints, foregoing a traditional upper control arm, such as a MacPherson strut. A radius rod (aka front trailing arm) and lower control arm locate the strut-mounted spindle (and bolt to the K-member). The lower control arm works longitudinally and laterally during suspension travel; the radius rod acts upon fore and aft movement during acceleration or braking. The sway bar (or stabilizer bar) uses a long end link to connect halfway up the strut, enacting roll resistance during cornering. It bolts to the K-member via brackets and bushings. The struts and springs are a coil-over style, mounting directly to the body structure and spindle and keep the tires planted during changing road conditions.
Although the front suspension bears close resemblance to other Zeta-based applications, the 4.5-link rear suspension was developed exclusively for the Camaro. In lieu of a double A-arm setup, such as on the Corvette, the Camaro uses a bulky L-shaped (stamped steel) upper control arm with a traditional lower control arm, trailing arm, and toe rod to locate the hub/wheel. The control arms guide vertical movement, the trailing arm acts upon everything else. The toe rod simply sets the toe angle of the rear wheels. The rear sway bar bolts to the cradle and connects to the lower control arms via end links to control body roll. The rear and front cradles are double-isolated from the body structure by rubber bushings, in addition to the rubber bushings found throughout the suspension. This does wonders to reduce NVH (Noise Vibration Harshness).
When equipped with the optional wheels, it could be difficult to tell a V-6 model from an SS. Although it is worth noting that the suspension and brakes were different altogether, not just the engine and drivetrain. Softer bushings and springs, thinner sway bars, etc., were also used.
The single-piston, floating calipers were a dead giveaway to V-6 models. The upside is that they also make great drag brakes, allowing for smaller and lighter drag wheels.
All SS models came with fixed, four-piston Brembo brakes. Although substantially sized, the weight of the SS made them simply adequate.
The 1LE offered many handling improvements over the SS, which was based on an in-house test-mule for the ZL1’s new suspension.
As for model variations, four suspension packages were offered on the fifth-gen Camaro (Camaro ZL1 and Z/28 also received unique components). All LS and LT V-6 models received the FE2 suspension. The SS convertible and 2010–2011 coupe came with FE3 suspension, 2012–2014 SS coupe used FE4 parts, and the 1LE came with FE6 parts. Each of the four used different sway bars, spring rates, and shocks to achieve different outcomes.
The V-6 models are known to have a smoother ride and the SS is noticeably stiffer. This is directly related to the FE2’s 25 N/mm spring rate and 96 mm of suspension travel in the front, and 53 N/mm rear springs enabling 115 mm of travel.
The FE3’s lowered ride height puts it at 84 mm of travel using 27 N/mm springs in the front, and 100-mm travel with 55 N/mm springs in the rear. Initially hollow sway bars were used to reduce weight; later models used solid bars for additional stiffness. The sway bars, shock valving, and spring rates are matched to the size and grip of the tires, as well as the weight of the car and other factors.
As formidable as even the Camaro SS coupe’s FE4 suspension is on a road course, the Camaro team certainly wasn’t done. The FE6 in the 1LE package builds upon this foundation by first tweaking the sway bars to dial in the handling as close to neutral as possible.
Goodyear Eagle F1 G:2 Supercar tires were designed especially for the ZL1 and 1LE, which greatly improved braking, as well as overall grip and handling. The specially designed wheels helped shave rotating mass. Despite the two wheel styles, it’s actually the same design; one has extra machining to cut out the center piece of the spokes.
The ride height, spring rates, bushing durometer, sway bar stiffness, and geometry were all optimized for the ZL1.
The ZL1 also had six-piston Brembo brakes with a two-piece rotor. Even with its increased weight, it still stopped on a dime. Both wheels used the same