The Lotus Esprit Almost Got The Corvette ZR-1's LT5 V8

The seeds of a potential Lotus Esprit ZR-1 sprouting into the sports car landscape in the early 1990s may seem as plausible as Jack's magical beans seemed to his mother (who tossed them out a window), but there's plenty of reason to think this pairing could have borne fruit. And like Jack taking an axe to that beanstalk, what a giant-killer that Esprit would have made! 

At the time the rumors started circulating in 1989, the "King of the Hill" C4 Chevrolet Corvette ZR-1's LT5 V8 was making 375 horsepower and 370 pound-feet of torque. The most powerful Lotus Esprit that year was the Turbo SE, which produced 264 hp and 261 pound-feet of torque. It was a step up from the 210 hp and 202 pound-feet the previous-gen Lotus Turbo Esprit, which you can find now for around $35,000. Considering their reliability reputation, you could just set fire to your money instead.

The SE's power numbers may sound middling by today's standards, but with a curb weight of about 2,900 pounds, it would hit 60 mph in 4.8 seconds and run the quarter in 13.5 at 102 mph. Imagine how those numbers would improve after adding more than 100 hp and 100 pound-feet of torque. Car and Driver estimated that the 5.7-liter LT5 DOHC V8 would add 300 pounds, so let's just call it 3,200. 

Punching the LT5-powered Esprit's specs into a calculator yields about 8.5 pounds per horsepower. For comparison's sake, a 3.6-liter 964-generation Porsche 911 Turbo had 355 horsepower and a curb weight of around 3,300 pounds, which makes for about 9.3 pounds per horsepower. That Porsche could pull to 60 in four seconds flat and run the quarter in 12.4 at 114 mph. So, performance for the 'Vette-sprit would have been blistering for the time.

In 1984, Lotus unveiled its Giorgetto Giugiaro-sculpted Etna sports car at the Birmingham, England, Motor Show. In addition to futuristic features such as active suspension and proximity radar, it featured a 330-hp double-overhead-cam 4-liter V8. GM wanted that engine. So, upon buying Lotus in January 1986 for its engineering prowess, GM asked ever so politely to graft those DOHC heads onto a Chevy small block V8 right dang now. Then, GM gently, quietly murdered the Etna behind the building. But the Etna-headed small block turned out to be way too big to install through the Corvette's frame rails, so GM said never mind, just design a whole new V8, anyway. 

In late 1986, Tony Rudd, Lotus' engineering director, explained to Roy Midgley, GM's chief engineer for the ZR-1 project, that this new 5.7-liter V8 would make 400 hp. Midgley noticed the 4.55-inch bore center spacing, and informed Rudd that Chevy small blocks have 4.4-inch bore spacing, so this new engine would, too. After presumably rubbing his temples for a minute, Rudd said the bores, valves, and consequently horsepower, would have to shrink. This was apparently acceptable, and Corvette ZR-1 LT5s rolled out of Mercury Marine's MerCruiser division (yes, the boat engine company) with 375 hp.

Cut to 1991. With the exception of rarefied beasts such as the cyberpunk-ish Vector W8, the ZR-1 was indeed the king of the hill. Also in 1991, a spy photo of an LT5-stuffed Lotus Esprit appeared in Car and Driver. Mike Kimberley, then CEO of Lotus, told Car and Driver it was just a "research project." However, Kimberley refused to say that Lotus wouldn't build it and stated the concept is "just resting."

There's absolutely zero concrete public information about why the "Lotus ZR-1" never made it to market. Perhaps the 1990-1991 recession played a role, as Car and Driver estimated the car's cost as $100,000, or about $248,000 today. Competition from other sports cars was also getting stiffer, as Lamborghini had just introduced the 200-mph Diablo, Dodge's Viper was set to launch, and Ferrari was improving the Testarossa to create the 512TR. Or maybe GM didn't want Lotus, its engineering plaything, making a car with a Corvette engine that was faster than the Corvette.

Regardless of the reason Lotus never got to pair the engine it designed with the car it built, GM sold the company to then-Bugatti-owner Romano Artioli in 1993. But though GM kept the LT5 as a parting gift, that didn't mean a V8-powered Esprit was off the table. Instead, Lotus took the development lessons it learned with the LT5 and put that effort into a new V8. 

In 1996, the Esprit finally got the cylinder count it deserved. With cast-iron cylinder liners, four-bolt main caps, and a forged crank, the new twin-turbocharged 3.5-liter flat-plane V8 was decently breakage-resistant, though at 350 hp and 295 pound-feet of torque, it wasn't an LT5. That said, the 3,067-pound Esprit V8 could rip to 60 in 4.1 seconds and through the quarter in 12.7 at 112 mph. 

So, we can firmly place the Esprit ZR-1 in the "what if" camp, along with cars such as the AMC AMX/3, Oldsmobile F-88, and Cadillac Sixteen. Even the LT5 V8 has its own "what if" scenario, as it left the market at 405 hp in 1995, but was intended to get an upgrade to 475 hp for 1996. Oh, well.