Zora Arkus-Duntov, the engineer who brought the original Corvette to life in the early 1950s, was a racer at heart. As a racer, he knew a mid-engine layout offered the greatest performance potential, but practical limitations and a pragmatic GM board stood in his way. That didn’t stop him from building a number of mid-engine prototypes to prove the concept and change minds, nor did it stop his successors from doing the same.
Over the course of three decades, Chevrolet built seven mid-engine Corvette prototypes under the guise of engineering development. Billed as Chevrolet Engineering Research Vehicles (CERV) or simply experimentals (XP), each was a radical engineering exercise for its time. None, however, convinced GM management to move the production Corvette’s engine behind the seats.
While the idea of a mid-engine sports car, perhaps wearing the Corvette’s crossed flags, can be traced back to Arkus-Duntov’s 1960 CERV I and 1964 CERV II and GM engineering boss F.J. Winchell’s 1964 Corvette Grand Sport II/II(b), all three were pure race cars and never meant for the street. XP-819 is the first prototype intended to be a street vehicle, but instead of putting the engine behind the seats, they put it all the way in the back, 911-style.
Designed to settle an argument between Arkus-Duntov and Winchell, who had his hands in the rear-engine Corvair, XP-819 featured an all-aluminum V-8 to help reduce the rear weight bias. It wasn’t enough. XP-819 was wrecked in testing and along with it, Winchell’s argument for a rear-engine design.
XP-880 Astro II
1967’s Astro I pioneered the aerodynamics, but it was powered by a rear-mounted Corvair powertrain. 1968’s Astro II was the first serious, street-focused, mid-engine Corvette concept. Built quickly from off-the-shelf parts in response to Ford putting the GT40 into limited production, Astro II featured Camaro and Corvette suspension parts, a 427 cubic inch V-8, and a Pontiac Tempest two-speed automatic bolted to the front of the rear-facing engine.
Astro II never actually got the Corvette name despite getting crossed flags on the hood, but it started endless speculation about the Corvette switching to a mid-engine design. Word has it the car was seriously considered for production, but in 1968, Chevrolet was selling the new third-generation Corvette hand over fist and had no incentive to tear up a winning formula, especially for a car that would likely be more expensive.
What Astro II started, XP-882 kicked into overdrive. The team knew the two-speed transaxle was a placeholder and would never hold up to the power they wanted to make. 1969’s XP-882 went big with a 454 cubic inch V-8 mounted transversely behind the seats to a modified Oldsmobile Toronado transaxle. Arkus-Duntov turned the drivetrain sideways to mount it lower in the chassis for better weight distribution and had to design a bevel gear to replace the Toronado’s differential so he could run a short driveshaft through a tunnel in the oil pan back to a Chevrolet differential.
XP-882 was never meant for public consumption, but Ford intervened again, announcing the sale of Ford-powered, mid-engine DeTomaso Panteras in the U.S. GM dragged XP-882 out on the show circuit in 1970 despite having just cancelled the project.
Now properly motivated again, Chevrolet authorized more work on XP-882, chiefly in the body work department. By 1973, the restyled XP-895 was ready with a steel body, but then the Reynolds company got involved. You know it as the aluminum foil company, and GM had contracted with Reynolds to develop aluminum body work. A second XP-895 was built with identical styling but with its body made entirely of aluminum. GM put it on the show circuit but, again, couldn’t find a business case for a production model.
At the same time Arkus-Duntov’s team was trying to make XP-882 and XP-895 happen, GM was also sinking huge sums of money into trying to make the Wankel rotary engine happen. Initially, GM thought it might be a packaging and cost win for the upcoming Chevrolet Vega small car, but saw its potential for sporty applications, as well. Given how small the RCE-266 two-rotor engine was, GM opted to do a special downsized Corvette concept built out of a Porsche 914 and bodied by Pininfarina. The Two-Rotor ‘Vette, as it’s known, was a dead-end, probably because of the car Arkus-Duntov was working on.
According to a 1980 interview, Arkus-Duntov was pressed into doing a rotary-engine Corvette concept by GM Car and Truck Group president Ed Cole. Not satisfied with the two-rotor motor in development, Arkus-Duntov effectively bolted two RCE-266 engines together to make a four-rotor engine with V-8 power. XP-882’s V-8 was ripped out, and in went the rotary, along with a third restyle of the sleek body. Named the Aerovette, it hit the show circuit shortly after XP-897GT in 1973, but it wouldn’t get far. The Yom Kippur War broke out, followed by the oil embargo, driving up gas prices and putting a fork in the thirsty rotary engine at GM, which had already spent big just getting the thing to pass new emissions laws coming into effect.
Three years later, GM design boss Bill Mitchell would catch mid-engine Corvette fever and pull the Four-Rotor car out of mothballs, drop in a 400 cubic inch V-8, and put it back out on the 1976 show circuit newly christened as the Aerovette. At Mitchell’s urging, the Aerovette was approved for production in 1980, but again, it wasn’t meant to be. Arkus-Duntov and Cole had retired in 1974, and the new Corvette boss, Dave McLellan, liked the engine up front. Mitchell retired in ’77, leaving the car without a powerful advocate at a time when emissions laws and a second oil crisis were putting a damper on performance. Meanwhile, Ford pulled out of the DeTomaso partnership in ’75, and other mid-engine cars like the Porsche 914 weren’t selling big, either. The fourth-generation Corvette, despite more than a decade of mid-engine speculation and false starts, would keep its engine in the front.
Corvette Indy Concept
A year of delays getting the fourth-generation Corvette on the road didn’t dampen Chevrolet’s renewed appetite for performance in the mid-’80s. GM engineering boss Bob Eaton was infatuated with Lotus cars and had hired Lotus Engineering to codevelop future sports car technologies. The earliest outward result was the 1986 Corvette Indy Concept (which premiered just before GM bought Lotus), a radical technological showcase. It featured a transversely mounted twin-turbo 2.6-liter IndyCar V-8 developed Ilmor mounted in the middle and driving all four wheels, but that was just the start. The Corvette Indy also employed four-wheel steering, computer-controlled active hydraulic suspension, carbon-fiber chassis and bodywork, ABS, traction control, stability control, electronically controlled throttle, a navigation system, and CRT video screens for rearview mirrors. Three cars, an initial styling concept and two running development cars, were built with the third going on to be reworked as the final mid-engine Corvette concept.
Based on the third Corvette Indy Concept built, CERV III was a slightly more consumer-friendly supercar of the future. It retained all of the Indy Concept’s wild future technologies but also had scissor doors (as opposed to the Indy Concept’s jet-fighter canopy) and an early, twin-turbocharged prototype of the future Corvette ZR-1’s LT5 dual-overhead cam, Lotus-designed 5.7-liter V-8 making 650 hp. The transversely mounted engine was connected to a three-speed automatic, which was connected to a custom two-speed automatic, which together could make for six forward gears. Power then went to a viscous coupling system that allowed basic torque vectoring between the front and rear wheels. Every wheel had two brake discs, a Big Mac sort of setup with fixed calipers to drag the car down from its estimated 225-mph top speed.
Chevy went as far as to raise the bumpers to meet legal requirements, open up the wheelwells for actual suspension travel (which was entirely computer controlled, made of titanium, and didn’t have or need shock absorbers), and install Corvette-heritage pop-up headlights.
GM would look seriously into putting CERV III into production, but it was never really going to happen. All the tech that’s commonplace to us today was Formula 1 stuff in 1990 and would’ve cost a fortune to build, necessitating a price tag that would’ve made it among the most expensive cars in the world.
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