This ZR-12 Corvette Was Created To Eclipse An Excessive Competitor

Some of the greatest Corvette creations were a direct result of an openly competitive challenger from across town. Such is the case with this over-the-top example of a C4 Corvette that was dipped in the pool of testosterone-laden monster juice back in the early nineties.


The ZR-12 was based on a ZR-1 platform which gave it the wider rear fascia and wider tires. It didn’t help.

When you think back to the way things were, you begin to understand just how obscenely over-the-top this Corvette creation was actually engineered to be. When the base model Corvette was capable of only 250 horsepower and pumped-up versions of the Callaway B2K (405hp) and ZR-1 (375-405hp) were deemed supercars and “The King of The Hill.” Anything that added the additional horsepower of another complete Corvette on top of either of them was in a word – excessive.

ZR-12 Corvette

Fitting that huge V-12 was impossible without making the whole engine compartment longer by eight inches.

But, when you’re fresh from a decade chock-full of shoulder pads and leg warmers, a little over the top is barely enough to put a blip on the radar screen. So, the mad scientists in GM’s Corvette skunkworks devised a plan. They caught wind that Dodge was building a vicious beast of a car, one that would bite any competitor, and sometimes, its owner if they weren’t careful. With a hulk of a V10, each one of those 400 horses it contained under its long-swoopy hood would surely run for their lives if given the chance. Somehow, even the King of The Hill’s 375 and later 405hp were left wanting.

The horsepower war was definitely starting to march to the chest-thumping drum of the Viper crowd and something needed to be done to wrest the attention back to the Bowtie camp. We would love to have been a fly on the wall when a true enthusiast of an engineer, somewhere in a board meeting, started a sentence with, “What if we…?” We’re sure a few pocket protectors melted after hearing about V12 engines and stretching their halo Corvette eight inches to fit it all in. Somehow, the stars aligned, a Corvette wound up eight inches longer and the bean counters found a way to pay for it all.

The entire front of the car was stretched to fit the V12. Coil packs make great use of the additional space.

Corporate officers aren’t in the business to pay for ego embellishments, so there had to be another reason to divert funds to create such a beast. That came in the form of durability testing. With a relatively new drivetrain to contain the power output of the new LT5 engine, engineers continued the conversation by asking how much more it could contain. The new ZF-designed 6-speed transmission was proving itself behind factory horsepower ratings and thanks to the efforts of GM engineers and several other outside sources, was found capable of corralling as many ponies as this behemoth’s V12 engine could muster.

The hood and the side gills are the only place where you can see the additional eight inches, and only if you’re looking for it.

To put a V12 in anything, you must first have a V12. That part came easy for Ryan Falconer Racing Engines of Chino Valley, Arizona. Their engines have found their way into street rods, trucks and even scaled-down, air racing P-51 Mustang aircraft. While the all-aluminum V12 is based on the small-block Chevy engine, fitting it into a C4 Corvette took a little more space management, thanks to the folks at SportsFab in Wixom, Michigan. They stretched the entire front of the car the necessary eight inches to fit another fifty-percent more small-block under the clam-shell hood. The entire subframe and hood were stretched, with evidence of the additional length most notable in the side gills area. Even with the addition of four more cylinders and eight inches to the car’s length, the weight of the vehicle is reportedly only 100 pounds more than the factory version, thanks to the V12’s all-aluminum block.

When the car was originally built, signs of excessiveness oozed out through those side gills in the form of black-coated side-pipes that neither hinted at noise abatement nor cared for emissions compliance. Over time, the furry knuckles were scrubbed and a complete under-car exhaust replaced the raucous boom tubes. Still, with over 600 horsepower and 680 lb/ft of torque, there’s plenty of grunt left over when the tall, skinny pedal is punched. True to this car’s nature, the Falconer Racing Engine’s website unapologetically states, “We do not perform any work on emissions-controlled engines or vehicles.”

The Falconer engine uses EFI to feed fuel to the beast and unlike the competitor that it was created to eclipse, the ZR-12 had air conditioning also!

In the early ‘90s, this car was nothing short of god-like status. In fact, engineers began to call it the “Conan Corvette.” For a short time, it pleased the press at long-leads when drivers like Corvette Powertrain Systems Manager Jim Minneker would shred those massive rear tires for over half the quarter-mile. The drivetrain proved completely adequate but the cooling system was not. The car was parked due to overheating issues and, after single-handedly captivating the horsepower-hungry, it was relegated to GM’s storage facility, where it languished for years.

Luckily, the car survived via the GM Heritage Center. The car wears several tags indicating its special heritage. The P9Y0074 means P=Prototype, 9=Year, Y=Corvette and 0074 is the car number. The metal "EX" plate denotes the car is an experimental build for engineering.

Thankfully, it was spared from a similar fate of many of GM’s “experimental” vehicles once their usefulness was completed. The plate beneath the windshield designates this car as experimental vehicle “EX5664” and as such, a life of the open road was never a consideration. Instead, the car spent a portion of its retirement in the GM Heritage Collection where it stood as a testament to at least one daring engineer who asked the question “What if…?” way back in the early nineties.

The car wears a complete early C4 interior, in agreement with the ’89 build date on the window sticker. Think about that, this was one of the ’89 ZR-1s that was converted.

Today, the car still wows enthusiasts, but with a little less exhaust note as before. It currently resides in the National Corvette Museum, where it is on loan from Chevrolet. The NCM Curator, Derek Moore recently did a short video highlighting the ZR-12 Corvette on one of his Monday’s With Moore segments. You can view the video HERE. We were honored to spend a little time with the Conan ZR-12 Corvette and to get a few photos of the car. It truly is a marvel to behold and anyone that has tried to squeeze any sort of power adder or additional goodies under the hood compartment of a C4 Corvette can surely appreciate how much effort it took to find the room for another four cylinders. If you’re ever headed through Bowling Green, Kentucky, be sure to stop by the National Corvette Museum and say “hi” to Conan, the ZR-12 Corvette and all the other rare and significant Corvettes they’ve got on display.

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About the author

Andy Bolig

Andy has been intrigued by mechanical things all of his life and enjoys tinkering with cars of all makes and ages. Finding value in style points, he can appreciate cars of all power and performance levels. Andy is an avid railfan and gets his “high” by flying radio-controlled model airplanes when time permits. He keeps his feet firmly grounded by working on his two street rods and his supercharged C4 Corvette. Whether planes, trains, motorcycles, or automobiles, Andy has immersed himself in a world driven by internal combustion.
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