This is one of just 25 Chevrolet Corvette ZR-1 “Active Suspension” prototypes that were ever made. The vehicles were developed in partnership with Group Lotus and the Lotus Formula 1 team as part of a $27 million GM R&D project.
General Motors had acquired Group Lotus in 1986, giving them access to what was widely considered to be one of the best automotive handling and suspension engineering teams in the world at the time.
Fast Facts – The Corvette ZR-1 Active Suspension Prototype
- The Chevrolet Corvette ZR-1 “Active Suspension” prototype is one of 25 developed with Lotus in a $27 million GM R&D project. It featured cutting-edge computerized hydraulic suspension system, and a powerful 375 bhp LT-5 V8 engine.
- GM acquired Group Lotus in 1986, utilizing their expertise in performance engineering, particularly in handling and suspension, to develop the ZR-1 as a high-performance version of the C4 Corvette.
- The active suspension system, derived from Formula 1 technology, used a Delco computer to hydraulically control each strut, maintaining body level through corners and dynamically distributing load for optimal handling.
- Despite its advanced engineering, the active suspension system wasn’t deemed ready for mass production. The 25 prototypes remain rare collector’s items, showcasing 1980s engineering innovation.
The Lotus + GM Developed Corvette C4 ZR-1
In the mid-1980s, after the 1986 purchase of Group Lotus by General Motors, a project was launched to create a version of the C4 Corvette that would be the fastest (or one of the fastest) production cars in the world.
Above Video: This is an original MotorWeek review of the 1996 Corvette ZR-1, as you can see, they were huge fans of the model and went so far as to call it a “supercar.”
Though it may have sounded like an ambitious undertaking, GM certainly had the budget for the project, and with the Lotus engineering department onboard they also had plenty of additional expertise at their disposal.
The car that was developed would be called the ZR-1, this is a special designation for a high-performance Corvette that had first been used on the C3 Corvette ZR-1 which had debuted in 1970.
The C4 ZR-1 engineering would be divided into two main sections: the engine, and an all-new computerized hydraulic active suspension system.
Lotus engineers developed an all new alloy V8 with a displacement of 5.7 liters, double overhead cams per bank, four valves per cylinder, electronic fuel injection, and an electronic computer controlled ignition system. Named the LT-5, this V8 was capable of 375 bhp, putting it on par with the 12-cylinder engines used by the likes of the Ferrari Testarossa and Lamborghini Countach.
The hydraulic active suspension system was even more cutting edge that the LT-5 V8, taking technologies that were being used in Formula 1 at the time and applying them to what was intended to be a mass-produced road car for the first time.
In short, the system that was developed used a Delco computer to hydraulically control each of the four struts to keep the body level through corners, across uneven surfaces, and under heavy braking.
This is the Lotus-developed LT-5 V8. It’s a 5.7 liter V8 with an aluminum block and heads, double overhead cams per bank, four valves per cylinder, and a total output of 375 bhp.
It could be set up to dynamically distribute load to improve the vehicle’s handling dynamics, and engineers quickly learned that they could create oversteer or understeer prone handling, or more neutral handling, purely through changes to the software.
Once the final prototype of the design had been agreed upon, it was installed into 25 pre-production prototype ZR-1 Corvettes at the Bowling Green factory in Kentucky. These 25 cars would be used for testing purposes, and for use by the media who were mostly smitten with the new technology at the time.
The End Of The Road
It was ultimately decided that the active suspension system wasn’t ready for use in a mass-production sports car. As a result the C4 Corvette ZR-1 was fitted with the Bilstein FX3 suspension system, using electronically adjustable gas-over-oil shock absorbers to alter the handling characteristics to suit the driver and/or conditions.
Many of the 25 active suspension prototypes have now made their way into the hands of collectors and enthusiasts, and they remain a testament to the remarkable engineering achievements of a bunch of British and American engineers in the 1980s – a time when the technology they were developing simply didn’t yet exist.
The ZR-1 Active Suspension Prototype Shown Here
The car you see here is one of the original 25 Corvette ZR-1 Active Suspension prototypes, it has just 12,000 miles on the odometer, and as you would expect, it’s powered by the all-aluminum 5.7 liter LT5 DOHC V8 which is mated to a ZF six-speed manual transmission.
The interior of this Active Suspension prototype is almost identical to the standard ZR-1, though there are a few indications that it has the rare 1-of-25 suspension system installed.
This ZR-1 is fitted with with fender vents, power-adjustable sport seats, air conditioning, an onboard computer, a tire pressure warning system, and power windows and locks.
It’s now being offered for sale out of Rochester, Minnesota on Bring a Trailer with a build sheet and a bill of sale, and it’s important to note that it’s currently only able to be used off public roads. If you’d like to read more about it or register to bid you can visit the listing here.
Images courtesy of Bring a Trailer
Articles that Ben has written have been covered on CNN, Popular Mechanics, Smithsonian Magazine, Road & Track Magazine, the official Pinterest blog, the official eBay Motors blog, BuzzFeed, Autoweek Magazine, Wired Magazine, Autoblog, Gear Patrol, Jalopnik, The Verge, and many more.
Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.
