Michael Accardi 
Thank goodness General Motors went bankrupt. If it wasn’t for decades of bad decisions and financial mismanagement, then this 1990 C4 Corvette ZR1 Active Suspension prototype would never have been sold into general circulation as part of liquidating GM’s remaining assets back in 2009.
On paper, the C4 Corvette ZR1 Active Suspension program looks like one of those bad financial decisions. A $28 million science project with Lotus–which GM had acquired in 1985 for $32 million–looked to infuse the Corvette with active suspension technology borrowed from the Lotus Formula One team.
C4 Corvette ZR1 Active Suspension Prototype: The Details
The system combined a high-powered Delco computer with a 3,000 psi hydraulic system. It’s thought that just 25 cars were built for developmental purposes. Only a handful remain, including this example that’s recently come up for sale down in Florida. Where all C4 Corvettes go to retire.
When operating, the Delco computer would hydraulically control the struts at each corner of the C4 Corvette ZR1 to actively level the body through corners and quell body motion over undulating surfaces. The system was even capable of maximizing axial load distribution. In order to get the algorithmic procedure right, the Delco box needed data. That data came from sensors that would relay vehicle speed, individual wheel speed, steering angle, throttle angle, and yaw among other things back to the box where the inputs were then parsed by the algorithm.
Some of you will recognize that this is almost exactly how modern electronically controlled damper systems function just with ’80s spec computing power and bus networks. In fact, systems like Active Handling which GM debuted in ’96, and MagneRide which showed up in 2005 are direct descendants of the C4 Corvette ZR1 Active Suspension program. But back in the early ’90s, there were several major issues with the Active Suspension system that would stymie its future.
The heat generated by a 3,000 psi hydraulic system was a major concern, so there were several auxiliary fluid coolers, with intake vents and heat extraction points added to the clamshell hood. The cost was a major factor as well, the Active Suspension system would have reportedly added close to a $30,000 premium over the base level ZR1. Durability was a factor as well.
Regardless of the success or failure of the program, the vehicle itself is a piece of automotive history. If you’re interested, this Corvette ZR1 Active Suspension prototype can be yours for just $89,500 from RMC Miami, listed on the Hemmings website. That’s probably what you’ll pay for a 2023 Corvette Z06 next year, so if you’re looking to store some value into automotive greatness, take your pick.
