A Brief History of the Z51 Package

A major performance upgrade for base Corvettes since the ’80s, here’s everything you need to know about RPO Z51.

Since its 1984 introduction with the C4 Corvette, RPO Z51 has always denoted a more serious Corvette. It’s a cut above the base car for sure, but these days, it doesn’t get as much attention thanks to models like the Z06 and ZR1.

In just a few words, we’ll do our best to tell you all about what has made the Z51 Corvette so special across four generations. While it’s not a comprehensive guide, this will let you know all about the basics of what the Z51 package includes for each generation.

The spiritual predecessor to the Z51 package was RPO FE7 — Gymkhana Suspension — offered on late C3 Corvettes. An FE7 car has stiffer shocks and springs, as well as larger sway bars.

C4 Corvette: 1984-1996

In 1984, the Z51 package included stiffer springs, larger sway bars, wider wheels, and a revised steering ratio. While standard wheels were 16×8.5″ wide, Z51 cars were fitted with 16×9.5″ wide rear wheels, and Goodyear Eagle VR50 tires all the way around. Almost every Z51 Corvette since would be fitted with stickier tires than the standard model. Starting in 1985, the wider 9.5″ wheels would be fitted at all four corners.

Z51 cars received special Delco Bilstein shock absorbers, as well as an auxiliary “boost fan” on the radiator and an upgraded oil cooler. In 1984, the Z51 option cost $600, or roughly $1,500 today.

Customers complained about the rough ride of 1984 cars, so for 1985, GM softened them up across the line. This was accomplished by using a less aggressive spring rate coupled with thicker sway bars. This gave 1985 and up cars better ride quality without sacrificing handling.

In 1987, RPO Z52, the Sport Handling Package, offered many of the upgrades found in the Z51 with a smoother ride. It stuck around for 1988, and was gone after the 1989 model year.

By the end of the C4’s run, many of the Z51-specific upgrades, such as the faster steering, upgraded cooling, and 9.5″ wide wheels, were standard on all Corvettes. At this point, the Z51 package just included the suspension upgrades — shocks, springs, and sway bars.

C5 and C6 Corvette: 1997-2013

When the C5 Corvette debuted in 1997, it carried the Z51 option over from the C4. As before, the Z51 package included a stiffer suspension and beefier sway bars. Automatic Z51s also received a steeper rear axle ratio, as well as a power steering cooler. At $350 — about $560 in today’s money — RPO Z51 was a downright bargain for the performance enthusiast.

The Z51 remained an option through the C5’s run and continued to be offered when the C6 debuted in 2005. The C6 Z51 package was much the same as the C5’s, but this time, upgraded brakes were added to the equation.

Z51 owners were treated to larger-diameter, cross-drilled rotors. Those with a manual transmission were treated to a close-ratio transmission, while automatic cars got a more performance-oriented rear axle ratio as before. The package price jumped to $1,495 for the Z51, but buyers received a lot more equipment for their money.

By this point, a Corvette hierarchy was more or less established. The Z51 package slotted neatly between base cars and the Z06. In 2010, the Z51 package was replaced with the Corvette Grand Sport. However, RPO Z51 would return for the C7 generation in 2014.

C7 Corvette: 2014-2019

The seventh-generation Z51 package returned with a bang. Z51 cars wore taggered wheels — 19″ up front, 20″ in the rear — and the upgraded brakes were fed by cooling ducts.

The cooling system upgrades went further than ever. The close-ratio manual was fed by a cooler, as was the electronic limited-slip differential. The engine was lubricated by a dry sump system usually seen in racing cars. A dual-mode exhaust was added to the package in 2015.

Of course, suspension upgrades were numerous, too. Z51 cars also had the option of adding on Magnetic Ride Control active handling and Performance Traction Management.

Indeed, this was the most comprehensive and ambitious Z51 package yet. Of course, all of this came at a cost — the Z51 package nearly doubled in price to $2,800 for 2014.

2020 C8 Corvette

The 2020 C8 Corvette debuted with the Z51 package as its sole high-performance option. The price took a big leap yet again, to $5,000. However, the list of included equipment grew to match.

C8 Z51s are, of course, fitted with an upgraded suspension. They also include Brembo brakes and Michelin Pilot Sport 4S tires.

The performance rear axle ratio has returned as well, along with an electronic limited-slip differential. Also included is the now-standard heavy-duty cooling upgrades. The C8 Z51 package also includes a performance exhaust, as well as unique front and rear spoilers.

With the C8 Z06 delayed until 2022 at least, the Z51 is the current king of the hill when it comes to Corvettes. For now, we’re more than happy with the performance offered by the Z51 package.

Photos: General Motors

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