2023 Corvette Nats highlight – ZR-1 C4
Fourth-generation (C4) Corvettes are usually the cheapest examples of America’s sports car you can buy, giving them a bit of a bad rap as bland and boring today. But when the C4 was new, it was far from that, especially in potent ‘ZR-1’ form, like the car shown here that was on display at this year’s Corvette Nationals.
Held in Ballarat this past March, the first Corvette Nationals since 2019 attracted in excess of 200 cars for the public Show ‘n’ Shine, covering almost the entire 70 years of Corvette production.
The C4 Corvette was launched in 1983 as a 1984 model and would remain in production until 1996. With a new chassis and new styling, the C4 was a complete break from the C3, which had been in production since 1967. After the last C3s were strangled by anti-pollution regulations, improvements in engine efficiency and emissions control technology meant performance was back on the menu with the C4, but it took a while to arrive.
A 350 (5.7-litre) small block V8 was the only engine available for the entirety of C4 Corvette production, and initially, this only offered 153kW (205hp), but the ‘L98’ version from 1985 produced 186kW (250hp). This improved again to 224kW (300hp) with the introduction of the ‘LT1’ variant in 1992, while in its final year, the C4 was available with an ‘LT4’ 350 V8 that offered 246kW (330hp).
But, for a Corvette buyer in the early 1990s who wanted the ultimate, there was the ‘ZR-1’, which offered 280kW (375hp) and 501Nm (370ft/lb) off the showroom floor, along with plenty of other improvements.
The ZR-1 name harked back to a hi-po Corvette variant Chevrolet had last offered back in 1972. Any new car wearing the ZR-1 badge had to be worthy of it, so to ensure this, General Motors turned to Lotus, who had already produced 260kW (350hp) from a 4.0-litre V8, so achieving the same power – or more – from the Corvette’s larger 5.7-litre V8 wouldn’t be a problem.
Dubbed the ‘LT5’, the 350 V8 that Lotus developed for Chevrolet featured multi-valve heads and double overhead camshafts to achieve 280kW. Exclusive to the Corvette ZR-1, the LT5 was matched to a six-speed manual transmission that was likewise exclusive to the halo model Corvette. Mercury Marine built each engine, as the LT5 was considered too specialised to go down the standard 350 production line.
Other features on the ZR-1 included larger disc brakes and wider rear tyres (with resulting wider bodywork), improved steering and suspension, leather trim and power seats, as well as tech like ABS and tyre pressure monitoring that wasn’t widespread in the late 1980s.
Only available as a coupe, the ZR-1 was released as a 1990 model, with early magazine testing showed it was capable of a top speed close to 290km/h and 0-100lkm/h acceleration in 5.0 seconds.
When Dodge launched their 298kW (400hp) Viper in 1992, the ZR-1 lost its crown as the most powerful American production car, so Chevrolet responded, calling on Lotus again to increase engine output to 302kW (405hp) and 522Nm (385ft/lb), while also reducing emissions.
The 1993 Corvette ZR-1 pictured appears stock in most areas, aside from the right-hand drive conversion. It’s one of 448 ZR-1s built for 1993, of which only 245 had the 40th Anniversary Edition cosmetic package, making this car doubly rare.
Available on the base Corvette coupe and convertible, as well as the ZR-1, the 40th Anniversary package featured Ruby Red metallic paint and identifying ‘40’ badges outside, while the seats and other interior trim carried a similar shade to the paint.
The popularity of the 40th Anniversary package (applied to 6,749 Corvettes in total) saw Corvette sales for 1993 rebound after four straight years of decline.
To see the JUST CARS report from the 2023 Corvette Nationals, click HERE.
