Riding sideways in the most powerful Camaro in history, we learn the value of big power, big noise, and total control.
From the December 2016 issue
Bursting airborne and sideways, wheels stretching for the ground, the raw, stunningly rapid, and now very aloft Chevrolet Camaro ZL1 should be a barbaric, deadly thing. Yet, in the crucial milliseconds following its oblique touchdown, it defines itself differently. Aaron Link, the ZL1’s lead development engineer, adds a breath of countersteer, stays in the gas, and carries the slide, fully committed, to the track’s edge. Crimson leaves explode behind its rear diffuser, then waft to the ground in what remains of the ZL1’s throat-punch exhaust note. The most powerful Camaro ever made fires a round of upshifts into the autumn air and hurls itself at the next corner, unfazed.
It’s a hell of a way to start the day.
“That’s the eLSD,” says Link, referring to the ZL1’s electronically controlled limited-slip differential, which it shares with the SS 1LE trim for 2017. “It’s scenarios like that that really sold us on the eLSD, despite its weight penalty.” The ZL1’s active diff weighs 44 pounds more than the clutch-type limited-slip differential in the Camaro SS, but it’s lighter than the massive 9.9-inch diff in the fifth-generation ZL1. And neither of those offered as much authority over these sorts of automotive gymnastics.
GM calls this ability “yaw damping” and offers no shortage of data to prove it works—all of which are less convincing than 1 minute and 53 seconds on its Milford road course. That’s about the time the ZL1 is capable of posting around the famed development track. Chevy won’t reveal the exact time but says it’s about three seconds quicker than the last ZL1, which ran a 1:56.
The ZL1, available as a coupe and a convertible, shares with the Corvette Z06 its herculean powerplant, the supercharged 6.2-liter LT4 V-8. Internally, both mills are identical—right down to the titanium intake valves and forged rods and pistons. In this latest King of Camaros, however, a conventional oil pan replaces the Z06’s dry-sump lubrication. Surprisingly, a lack of packaging space demanded the change. But what matters is this: 650 horsepower at 6400 rpm and 650 pound-feet of torque at 3600 rpm. It’s all managed, aurally, by a dual-mode exhaust, which is now electronically controlled rather than vacuum actuated as it was on the last ZL1. Chevy offers two transmissions here, including a high-torque version of the six-speed Tremec TR6060 that’s available in the Camaro SS. A tailored gearset allows the manual-transmission–equipped ZL1 to hit 60 mph in first gear, while both fifth and sixth are overdrive gears. At 0.54:1, sixth gear is a true fuel-economy cog, though the 3.73 final-drive is still low enough to serve up shovel-to-the-spleen holeshots.
But the 10-speed automatic, co-developed with Ford, is the one that’s so hotly anticipated and the one we experienced from the passenger’s seat. Even from that chair, it’s clear that it will be the go-to gearbox if minimizing lap times is a priority. Chevy engineers compared the 10-speed’s shift times with those of the dual-clutch units in the 991 Porsche 911 Carrera S and the McLaren MP4-12C, which admittedly are not the newest iterations of those cars. The differences, though small, fall convincingly in favor of the Chevy. Here the 10-speed uses a ZL1-specific torque converter, clutch components, bearings, software, and controllers. Its 0.64:1 10th gear is numerically lower than what the transmission will offer in other applications. Ten-speed–equipped ZL1 coupes will have a 2.85:1 final-drive ratio. Convertibles will be 2.77:1 and won’t get the eLSD. Most striking is the gearbox’s ability to keep the LT4 engine almost indefinitely in the most potent portion of its rev range. When it’s working hard, the 10-speed is all nervous energy, ripping through tightly spaced gears with unrelenting pace. The resultant thrust and sound are gleefully rewarding. Enough so that Link says the automatic is the component of the car that makes him most proud. “It just never falls off,” he says. “Even at the higher speeds we see on the ’Ring [the Nürburgring Nordschleife, where GM partially developed the ZL1], there’s always a building sensation to this car’s acceleration.”
|The “flow tie” hollow Chevy grille badge, borrowed from the old Z/28, graces a front end that is constructed almost entirely of air intakes.|
Four drive modes influencing all the car’s manners remain: snow/ice, tour, sport, and track. It’s likely, though, that the 10-speed has crossed the don’t-bother threshold when it comes to do-it-yourself paddle shifting. Even Link admits that it’s hard to know whether to go down three gears or four in certain scenarios. But, let’s face it, the days of shifting automatics yourself stopped being rewarding back when they reached seven gears. Using drive, as Link did on our ride-along, frees up brainpower for steering and braking. If you want to shift yourself, get the six-speed.
Back at Milford, a few corners later, Link shortens a bend and squares up the curb’s leading edge with the ZL1’s right-front tire. It’s a move that should deliver a full-wind-up nut shot to the spring and damper, further ventilating the already thoroughly ventilated hood. But the ZL1 shrugs off the blow and sticks unflinchingly through the remaining esses, launching us to 160 mph on the front straight, which isn’t really straight at all. Magnetorheological dampers, standard on the ZL1, play no small role in the car’s preternatural control and are perhaps the greatest ally to the car’s Performance Traction Management system, which applies the exact torque the rear wheels are able to put down in virtually any scenario. How effective is the ZL1’s PTM system? So much so that Drew Cattell, the ride-and-handling engineer who drove the ZL1 for its Nürburgring hot lap, relied on its reassurance through the Green Hell’s 12.9 miles. Link, during our laps, drove fully unrestricted.
Chevy hadn’t released the ZL1’s official ’Ring lap time as of our deadline. But it did say that the new car is more than 11 seconds quicker than the previous ZL1’s 7:41.27, which makes it a 7:30 or better. We’ve seen data logs confirming that it’s 10 mph faster than the old ZL1 (call it about 182 mph) going into Tiergarten, the fastest section of the track. A mid to low 7:20 seems possible.
|The ZL1 has a line-lock feature for those who enjoy turning their rear tires into smoke, but the car was, instead, designed to destroy its tires on a road course.|
Broad-shouldered, wide-hipped, and gape-mawed, the ZL1 is a caricature of the now devastatingly ordinary SS. Its front fenders are 0.6 inch wider on each side than the SS’s, partially to cover huge rubber and partially to allow more cooling air to the array of heat exchangers housed in the ZL1’s nose. And that hood? It’s a functional two-piece aluminum-and-carbon thing that extracts air from the engine compartment. Wind-tunnel time largely determined the shape of the ZL1’s nose, which divides its work between managing lift and drag and cooling the powertrain and brakes. Despite its Sofia Vergara–esque bulges, this ZL1 presents about 2 percent less frontal area than the previous model, which, coupled with an additional 70 horsepower, should yield a measurably improved top speed. GM isn’t releasing that number yet, but the fifth-generation ZL1 managed 184 mph flat-out. We expect this ZL1 to just miss the 200-mph club.
Forged 10-inch-wide front and 11-inch-wide rear wheels wear 285/30R-20 and 305/30R-20 rubber, respectively. Goodyear, once again, is the ZL1’s tire supplier, and it worked with engineers through many variants of its Eagle F1 Supercar tire before arriving at the final compound and construction, which is called G:3.
Carbon-ceramic brake rotors, like those offered on the 2015 Z/28, aren’t available. This is both a cost-control measure and a practical one, as the iron brakes meet GM’s performance targets. The ZL1’s two-piece 15.4-inch iron front rotors are clamped by fixed, six-piston Brembo calipers. Even with hefty brakes, the Alpha platform nets the ZL1 a 220-pound weight savings over the last model; at about 3950 pounds when equipped with the 10-speed automatic, though, it’s certainly no featherweight. Still, it’s quicker. Chevy says 10-speed–equipped coupes should hit 60 in 3.5 seconds and hammer through the quarter-mile in 11.4 seconds at 127 mph.
Customizable launch control that allows adjustable engine speed and wheelslip between 5 and 15 percent is standard and can be had with either transmission. And, keeping pace with Ford, the ZL1 now offers line-lock, a feature that clamps the front brakes but leaves the rear free for epic burnouts. It’s so buried in the instrument-cluster menus that even Captain Liability himself couldn’t accidentally activate it.
Chevy is prepared to sell you a ZL1 coupe for $62,135 when it goes on sale this month. The convertible will follow in the spring for seven grand more. Both will be subject to gas-guzzler taxes, and their gratuitously burned hydrocarbons will be worth every extra penny.
It shouldn’t surprise us that this car can at once be so unapologetically raw and yet so seemingly controllable. So loud and yet so articulate. Finding those traits melded in a single piece of hardware like the ZL1 is one of the great joys of being a car enthusiast today. And it’s quite likely that the ZL1 is the most rewarding means ever created to move leaves off a racetrack.
Tech Highlight: Cooling That Goes to 11
That the ZL1 packages 11 heat exchangers into its powertrain shouldn’t surprise you. Six hundred and fifty, after all, are a lot of ponies to chill. Of the 11, seven are air-to-liquid coolers and four are liquid-to-liquid. There’s an air-conditioning condenser packed in there as well because drivers need cooling, too. Chevy engineers came up with a novel solution for keeping the ZL1’s active differential from cooking its lube. Cooled transmission oil is routed to a heat exchanger inside the differential housing where it extracts heat from the differential oil. An auxiliary transmission cooler is packaged horizontally and sits under a wind-tunnel-designed cover that protects it from road debris and increases flow through its core. Cool.