Road & Track 2019 Chevy Corvette ZR1 Ultimate Review. The 2019 Chevrolet Corvette ZR1; The 755-HP Front-Engined Vette to End All Front-Engined Vettes To make a Corvette even mightier than the Z06, you need only two things; power and downforce.
2019 Chevy Corvette ZR1 Ultimate Corvette Review
This New ZR1 is precisely one step beyond just “more.” Longtime Corvette chief engineer Tadge Juechter describes the ZR1 as “the most we know how to do.” Here, the most means 755 horsepower and 715 lb-ft of torque. And it starts, as it did in 1990 on the first ZR1 that most people remember, with an engine called LT5. With pushrods instead of its ancestor’s dual overhead cams, though, this LT5 is an evolution of the 6.2-liter LT4 powering the current Z06. Like the Z06’s engine, this one is capped by an Eaton supercharger. The blower is bigger than the LT4’s, pumping 52 percent more air with each revolution, and taller by 2.9 inches. Corvette exterior design manager Kirk Bennion says that, when the design team tried to maintain typical hood clearances, “you got behind the wheel, and you couldn’t even see the right side of the car.” Faced with this difficulty, his team decided to stay home.
Stay home from Europe, that is. Forgoing European sales and ignoring the Continent’s rulebook meant not having to meet its stringent pedestrian-protection regulations. In Europe, the head of anybody who steps in front of a moving car is entitled to smash through a minimum amount of (relatively) soft material and space before contacting hard engine parts such as intake manifolds, superchargers, or intercooler bricks. Here in the U.S.A., we have thicker skulls—perhaps related to an above-global-average dairy intake—and our regulators will let you bonk your noggin on an engine that sticks up through the hood. The largest chunk of that carbon-fiber strip running down the center of the ZR1’s nose is, in fact, the intercooler cover. As Juechter describes it: “You’ve got no air gap between the engine and the hood, you’ve got no hood blanket, you’ve got no construction between the hood inner and outer. All that stuff usually stacks on top [of the engine], but we consumed all of that and then let the engine crawl out another inch, inch and a half.” Adds Bennion: “It was a challenge to get that hood right. It could get real backwoods on you real fast.”
While you can now see the right side of the car, the view from the driver’s seat is still plenty dramatic: Luke Skywalker’s as he zooms down the trench toward the Death Star’s exhaust port. And, Juechter promises, it’s even more dramatic when you start the car. “[The engine] moves around on you. You step on it, you can see the engine trying to pick the front of the car up and come out of the hole. Every twitch of your foot, you can see how the driveline is moving. It’s part of the charm.” In much the same way a great white chomping on the bars of your dive cage is part of the charm. We’re also told the LT5 will shoot flames from its exhaust, so there’s even charm for the people behind a ZR1. That last bit is a conveniently bad-ass byproduct of the engine’s new fuel-delivery system, which uses both port and direct injection. At the other end of the combustion cycle, there’s another benefit to Corvexit: louder exhaust. U.S. pass-by noise regulations allow more decibels than do the European Union’s. In addition to the electronically controlled butterfly valves in a Z06, the ZR1’s exhaust system incorporates a newly patented internal valve that Juechter likens to the flap on top of a semitractor’s exhaust pipe. A spring holds it closed under light loads, but as exhaust flow grows more urgent, it overcomes the spring pressure and pushes the valve open, allowing for a smoother rise to the volume than the all-or-nothing character of the butterfly valve alone.
Beyond the larger supercharger and the fuel-injection system, the biggest differences between the LT4 and LT5 are the latter’s larger throttle body and strengthened crankshaft. Even with the computer dialing back the torque output in the lower gears, Chevy figures the ZR1 will hit 60 mph in less than three seconds, clear the quarter in less than 11, and top out beyond 210 mph. Juechter says: “Some companies, when they go up in horsepower, what they’re really doing is just extending the torque curve . . . the peak torque isn’t higher at all, it just extends a little bit. We’ve elevated the torque across the range. It feels stronger than a Z06 all the way through the gear run-up, not just a little extension at the end.”
“If you’re going to engage in an endeavor like this,” adds Tom Peters, “you need that noticeable transition or contrast. You know a customer is going to expect it.” As design director for performance cars at General Motors, Peters shouldered much of the responsibility for the other half of the ZR1’s story: aerodynamics. Aside from the rear wing and different wheels, the Z06 and ZR1 are identical aft of the A-pillars. Forward of them, no bodywork is shared, and engineers crammed an additional four heat exchangers into the nose. Each outboard nostril contains a new radiator and intercooler. The two intercooler bricks underhood are enlarged to twice the size of the LT4’s. The ZR1’s larger blower and additional coolers add some 140 pounds to the Z06’s curb weight, most of it concentrated in the nose. A chief collaborator on the ZR1’s styling was air. Maximizing airflow through all those exchangers meant extensive wind-tunnel development, using both scale models and full-size cars in a rolling-road wind tunnel. “We see aerodynamics as an opportunity to make the car more unique, more pure and genuine,” Peters says. “To me, that’s universal truth, and that’s design.”