The threats to the Corvette were obvious though, and a plan to design and build an advanced new engine to help defeat its rivals was put into motion almost immediately.
With help from Lotus, General Motors developed what became the 'LT5' engine. It was an all-aluminium quad-cam 32-valve 5.7-litre V8, built by Mercury Marine, that developed an impressive 375bhp at 6000rpm and 370lb ft at 4800rpm.
In 1990 the ZR-1 went on sale to the public and - outside of Callaway's efforts - became the pinnacle of the Corvette range. Prototype versions had earned the nickname 'King of the Hill', and it was a moniker that stuck. Here was a 1572kg coupé that could sprint from 0-62mph in 4.5sec and exceed 180mph.
What was most impressive about the ZR-1 was its durability. In March 1990 a ZR-1 set several records, including a new world record for the 5000-mile endurance challenge. It covered the distance in 28 hours and 46 minutes at an average 173.791mph, breaking the long-standing 156.824mph average set by the Mercedes-Benz C111 in 1976.
Besides its dramatically different engine, the ZR-1 also benefitted from a range of other upgrades including better brakes, retuned adjustable active ride control modes, a wider tail and 11-inch rear wheels - compared to the standard C4's 9.5-inch items.
All came with a six-speed manual transmission, a limited-slip differential, electrically adjustable seats, climate control, cruise control and an innovative 'valet' mode that cut power to around 250bhp.
Admittedly the comfortable interior wasn't on a par with the likes of a Porsche or Ferrari, cars that performed in a similar fashion, but new the ZR-1 cost around £38,500. A Porsche 911 Turbo from the same era would set you back a cool £63,000. Its less attentive fit and finish can, consequently, be forgiven to an extent - and you could always take comfort in knowing that the money had been spent where you really needed it to be.
This 1991 example ticks a lot of the right boxes and its asking price of £15,000 is two or three times less than what you'd pay for an early ’90s 911 Turbo. It's covered a sensible 56,000 miles, appears well cared for, is claimed to be in superb condition and comes with a host of desirable upgrades - including upgraded brakes.
It's pleasing to see that the brakes have been fettled, because this particular ZR-1's engine produces significantly more than it did when it left the factory. It's received a set of gas-flowed cylinder heads, aftermarket exhaust manifolds and a Corsa sports exhaust system - all of which bumps its output up to a claimed 444bhp.
Even a stock ZR-1 should prove capable of repeatedly and reliably beating far, far more costly cars away from red lights. The extra power should consequently give you even more of a competitive edge, providing you've the necessary traction.
As you'd hope it's taxed and tested too, so you can drive it away and immediately begin revelling in its prodigious output. They're mechanically very durable, so you should have few problems, even if you drive it hard, provided you maintain the ZR-1 properly.
Its running costs shouldn't break the bank either, provided it's a good example, and even the fuel consumption should prove tolerable. When new, GM claimed the Corvette could average a tolerable 24.6 imperial MPG.