The Lotus Esprit almost got the LT5 V8 from the Corvette ZR-1 – Jalopnik

The seeds of a potential Lotus Esprit ZR-1 that germinated across the sports car landscape in the early 1990s may seem as plausible as Jack’s magic beans seemed to his mother (who threw them out the window), but there’s plenty of reason to believe this combination could have paid off. And as Jack takes an ax to that beanstalk, what a gigantic killer Esprit would have made!

At the time rumors began circulating in 1989, the LT5 V8 of the “King of the Hill” C4 Chevrolet Corvette ZR-1 produced 375 horsepower and 370 pound-feet of torque. The most powerful Lotus Esprit that year was the Turbo SE, which produced 264 horsepower and 261 pound-feet of torque. It was a step up from the 210 horsepower and 202 pound-feet of the previous generation Lotus Turbo Esprit, which you can now find for around $35,000. Given their reputation for reliability, you might just set your money on fire instead.

The SE’s power may sound mediocre by today’s standards, but with a curb weight of about 2,900 pounds it would reach 60 mph in 4.8 seconds and quarter in 13.5 mph at 100 mph. Imagine how those numbers would improve after adding more than 100 horsepower 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 call it 3,200.

If you enter the LT5-powered Esprit’s specs into a calculator, it yields about 8.5 pounds per horsepower. For comparison, a 3.6-liter 964-generation Porsche 911 Turbo had 355 horsepower and a curb weight of about 3,300 pounds, which works out to about 9.3 pounds per horsepower. That Porsche could hit 60 in four seconds and complete the quarter in 12.4 at 110 mph. The performance of the ‘Vette spirit would have been thrilling for that time.

In late 1986, Lotus technical director Tony Rudd explained to Roy Midgley, GM’s chief engineer for the ZR-1 project, that this new 5.7-liter V8 would produce 400 horsepower. Midgley noted the 4.55-inch center spacing and informed Rudd that Chevy small blocks have a 4.4-inch bore spacing, so this new engine would do that as well. After rubbing his temples for probably a minute, Rudd said the bores, the valves and therefore the horsepower should shrink. This was apparently acceptable, and Corvette ZR-1 LT5s rolled out with 375 horsepower from Mercury Marine’s MerCruiser division (yes, the boat engine company).

Cut to 1991. With the exception of rarefied beasts like the cyberpunk-esque Vector W8, the ZR-1 was indeed king of the hill. Also in 1991, a spy photo of an LT5-filled Lotus Esprit appeared in Car and Driver. Mike Kimberley, then CEO of Lotus, told Car and Driver that it was just a “research project.” However, Kimberley declined saying that Lotus would not build it, stating that the concept “just rests”.

Regardless of why Lotus was never allowed to pair the engine it designed with the car it built, GM sold the company to then Bugatti owner Romano Artioli in 1993. But even 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 poured that effort into a new V8.

In 1996 the Esprit finally got the cylinder number it deserved. With cast-iron cylinder liners, four-bolt main covers and a forged crankshaft, the new 3.5-liter flat-plane twin-turbo V8 was quite break-resistant, although with 350 horsepower and 295 pound-feet of torque it was no LT5. That said, the 3,067-pound Esprit V8 could rip to 60 in 4.1 seconds and go through the quarter in 12.7 at 110 mph.

So we can put the Esprit ZR-1 firmly in the “what if” camp, along with cars like the AMC AMX/3, Oldsmobile F-88, and Cadillac Sixteen. Even the LT5 V8 has its own ‘what if’ scenario, as it launched in 1995 with 405 hp, but would be upgraded to 475 hp in 1996. Oh well.