Ever since the arrival of the C6 ZR1 the “ZR1” moniker has represented the most extreme of performance Corvettes. The ZR1’s roots are solidly embedded in Corvette racing and are directly connected to the godfather of performance Corvettes: Zora Arkus-Duntov. In Zora’s day, there was no official GM or Chevrolet Racing program, so Duntov had to go covert with his “racer kit” RPO program. In 1957, Duntov and three-time Indy 500 winner and engineer Mauri Rose, started offering Chevrolet-engineered heavy-duty parts for racers. Until the arrival of the 1967 427 L88, the various number RPO kits offered suspension and brake packages designed to be used with the small-block fuelie Corvettes. The now revered Z06 moniker was once just another performance RPO parts package and was only offered in the Chevrolet Parts Department list in 1963. Most Corvette buyers didn’t even know about the racer kit packages because they were not shown in the Corvette sales brochures, and were truly only of any value if a customer was going to road race their Corvette.
The L88 racer kit was offered from 1967-1969 as Duntov’s “Cobra Killer” setup for big-blocks. The ultimate big-block version of the L88 was the ZL1 that was essentially an L88 with an aluminum block. The ZL1 block alone was a $3,000 option on top of the $1,032 L88. While Zora loved the horsepower and torque of the big-blocks, his roots were in the lighter small-block configuration. In the early 1960s he worked very hard to get an all-aluminum small-block into production. Unfortunately, the basic castings were never designed for aluminum and lacked the durability needed for racing … but what a tantalizing possibility. To offer a racer kit for his small-block customers, from 1970-1972 RPO ZR1 was on the parts list. This was essentially the L88 suspension and brake package for Vettes powered by what was at that time the wildest small-block to date: the LT-1. The 1970 ZR1 package cost $968 and by 1972 the price went up to $1,010. Only 53 1970-’72 ZR1s were built.
Fast-forward to the mid-1980s, the Corvette was chief engineer Dave McLellan’s baby. GM had purchased Lotus Engineering and McLellan saw an opportunity to offer his customers something very special, but not just for racers. The Lotus-engineered LT5 engine powered what was the most exotic street Vette offered to date. The LT5 was Duntov’s dream-engine come true: all-aluminum, fuel injection and using efficient pentroof cylinder heads and dual-overhead cams. The only way the LT5 could have been more exotic was if it had been turbocharged. Unlike the previous ZR1, the C4 edition was a separate model and designed to be a road machine, although a few were raced.
The C4 ZR-1 was a quantum leap over the regular Corvettes. In 1990, the basic L98 engine was rated at 250 horsepower. Packing 375 net horsepower, the ZR-1 was quicker and faster than the big-blocks of the ’60s. The power gap closed some in 1992 with the Gen-II small-block LT1 (300 hp), but the gap grew in 1993 when engineers bumped the LT5’s horsepower to 405 hp for the 1994 and 1995 ZR-1s. This was a total package Corvette, as the drivetrain, suspension, brakes, and tires were heavy-duty and designed to match the LT5’s capability. Because the tires were significantly wider, the entire back end of the car, including the doors, were unique to accommodate the widest tires ever offered on a production Corvette.
The unique body was arguably the weakest part of the C4 ZR-1 because it looked almost exactly like the stock C4. Even the wider ZR-1 wheels were styled to look like the regular Corvette turbine-vane wheels. For 1994 and 1995, ZR-1s had painted-silver, five-spoke wheels that were not available on regular Corvettes. From 1990-1995 Chevrolet only sold 6,922 ZR-1s thanks to its nose-bleed price. In 1990, the ZR-1 option alone cost $27,016 on top of the $31,979 base price, making the $58,995 ZR-1 the most expensive Corvette offered to date! By 1995, the price was up to $31,258 on top of the base cost of $36,785, for a total of $68,043.
However, what every ZR-1 owner definitely had was bragging rights when they popped open the hood of their ZR-1. The LT5 looks “stuffed” under the hood, not unlike the big-block 1965-’74 Corvettes. The LT5’s fuel injection intake looks like it has eight-pack abs and the DOHC heads look huge, like a Chrysler Hemi. Even though the modern, high-tech C7 Z06 LT4 engine has 245 horsepower more than the C4’s LT5, the C4 ZR-1’s engine is a jewel, as distinctive as the 1967-’69 427 3x2 big-blocks. After the ZR-1’s exit at the end of 1995, the last of the C4s offered two, much less expensive special editions: the Collector Edition and the Grand Sport.
The 1997-’04 C5 generation was such an improved car. There wasn’t a longing for a ZR-1 model, especially after the Z06 was introduced in 2001. Why the hardtop model-based Z06 wasn’t called “ZR-1,” only Chevrolet knows. But it was the C6 Z06, with its all-aluminum frame, 427 LS7 engine, dry-sump oil system, wider wheels and tires, all wrapped in an aggressive widebody that put Corvette closer to an all-out racer than any previous model. The C4 ZR-1 was relegated to a nice, but powerful semi-collectible Corvette, and the ZR-1 moniker was off the radar.
What made the C6 ZR1 so unique was that even though it used the basic Z06 widebody, it had distinctive characteristics. Most obvious was the plexiglas window in the hood that showed the top of the ZR1’s LS9 supercharged engine. While the concept might sound gimmicky, the execution was excellent. The ZR1’s other unique body parts included dedicated front fender vents, a more aggressive front air splitter, side rocker skirts and full-width rear spoiler. This was the beginning of an ongoing series of racer-inspired ground effects and air management improvements. The ZR1’s 20-spoke wheels are a thing of beauty.
Even though the ZR1 had 133 horsepower and 123 lb-ft of torque more than the Z06, the car wasn’t supposed to be a racer. This was an all-out GT machine in the true sense of the expression: a strong frame, racer-inspired suspension, outstanding brakes, gobs of power and all the creature comforts needed for spirited, long-distance travel. However, just like the C4 ZR-1, power and uniqueness comes at a cost. The first 2009 ZR1 cost $103,300 and the last 2013 ZR1 went for $112,575. The C6 ZR1 total production was 4,684 units.
So what might we see on the 2018 ZR1? The car will obviously use the Z06 structure and suspension. We won’t see exotic inboard brakes and the spy photos don’t indicate a wider body. The front air intakes could easily be more racer-like and I wouldn’t mind seeing the return of the peek-a-boo hood. The ZR1 should definitely have dedicated wheels, as light as or lighter than the Z06 wheels. Spy photos show star-shaped, Ferrari-like wheels. Some of the spy photos show a large, racer-style rear wing, similar to the 2010 Z06X concept Corvette. Comments on websites showing the winged version indicates a “love it or hate it” response. And since the Z06 is available as a coupe or roadster, the ZR1 will also be available as a coupe or roadster. The C7’s interior can already be boutiqued-out and nothing is glaringly missing from the order sheet, but I’m sure we’ll see “ZR1” embroidery, badges, and perhaps special accent lighting. The engine that will power the ZR1 won’t be all-new, but most likely an extreme version of the Z06’s LT4, wearing the moniker, “LT5” as a nod to the Lotus-designed C4 LT5. The new ZR1 needs a minimum of 750 horsepower, but more would be better so that the ZR1 isn’t just on par with the new Shelby GT500 Super Snake. Can Chevrolet engineers get to a streetable 800 horsepower? It’s all getting pretty crazy.
The new ZR1 will make its debut at the North American International Auto Show in Detroit in January 2017, just after you read this on superchevy.com, and definitely after the debut on the paper pages of Vette magazine. The car will be very expensive, but will have to be its own character, distinctive at a glance, that it isn’t just a Z06 or Grand Sport. Corvette engineers and product planners have a track record of surprising and not letting us down. I predict a grand slam!
K. Scott Teeters has been a contributing artist and writer with Vette magazine since 1976 when the magazine was titled Vette Quarterly. Scott’s Corvette art can be seen at www.illustratedcorvetteseries.com. His muscle car and nostalgia drag racing art can be found at www.precision-illustration.com.