The ZR-1 was too expensive to succeed — but too good to ignore | Jason Cammisa Revelations | Ep. 16

One of the design briefs for the C4 Corvette was that it had a minimal frontal cross-section, so it was less visible to radar. In other words, it helped you get away with speeding.

Another target was to be the most powerful car sold in America. The 1990 - 1995 Corvette's ZR-1 option package was the most expensive in the history of Detroit, but it gave the Corvette world-beater firepower.

Its LT5 V-8 was designed by Lotus and built by Mercury Marine, an all-aluminum, four-cam V-8 that was developed from the Lotus Etna concept engine, not a Small Block. It shared the traditional Small Block 4.40-inch bore spacing (after a quick redesign) and used an early form of passive Variable Valve Timing.

The 32-valve V-8 breathed through 16 individual intake runners, half of which could be closed off at low loads. When opened, those runners breathed through valves that ran on a far more aggressive cam profile. This allowed the engine to be both torquey and efficient at low-rpms, but powerful at the top.

The 2023 Corvette Z06 is the first DOHC V-8 in a Corvette, but the ZR-1 was the only ever installed in the front.

And through the ZR-1 broke records, it wasn't the sales success that Chevrolet had hoped for — and there are many very interesting reasons why - culminating in the grudge-match development of the LS-series Small Block.

Host Jason Cammisa takes us through the story in this episode of Revelations.

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[angry_zergling]

Yeah designing part of the car to minimize radar signature has to be one of the most badass things I've heard in a while.

[davemclellan]

You got a lot of this right because you read my book, “Corvette From the Inside.” The inclined radiator was, first, a feature of the C3. A Skunk Works team members said it was one of the clues that directed them toward stealth. The ZR-1 windshield was heat reflecting in order to enhance AC system performance. It would also have prevented garage door openers from working and, yes, it would have made Radar Detectors ineffective. Thus, the window in the windshield,

I don’t think Chevrolet Sales and Marketing, with few exceptions, understood the Corvette very well nor did they understand how it could help Chevrolet so it was, from its beginning, an orphan. So, we set about to change that. Unfortunately, Lloyd Reuss moved too quickly out of a direct role in support of the Corvette so the ZR-1 seemed more of a burden to Chevrolet. That, as a production Chevrolet, it could run 180 mph for 24 hours, to set an FIA World Endurance Record of 175.885 mph with only stops for fuel, tires and driver changes. meant little to Chevrolet. Actually they didn’t think we could do it and planned accordingly. We knew otherwise. Marketing then took the Corvette Advertising budget and gave it to support the sail boat America Cube (A3) in the America’s Cup sail boat race. A3 was a looser.

We showed them what GM Engineers were capable of. It took the GM bankruptcy for Chevrolet to finally understand the Corvette.

[MrWeeace]

I had a 95 ZR1...It was absolutely amazing.. Sold it for a wife and kids.. It was a bad trade.

[mgabrysSF]

I don't know why I discovered this channel so late - but this is right up there with Regular Car Reviews.

[raremage]

Great video. I’ve owned two C4’s and one day I got pulled down by a speed trap. The deputy actually told me she had hoped I would run because she had “never chased a Corvette.” She also told me she had a hell of a time getting a radar reading on me “for some reason.”

She let me go with a warning.

[subaruanon]

Finally, it's so rare to find someone who doesn't just blindly hate on the C4 like everyone else. God the C4 ZR1 is so cool.

[delarestudio]

About a year ago I acquired a 1990 ZR-1 with 10k miles and thought I would just make it a garage queen while the values went up. Then I took it for a drive. A year later it has 13K on it and I wouldn't get rid of it. these cars are made to drive, and while I have owned a lot of fun cars, including two C7's, this thing is fun to drive and makes the best engine noise ever with an engine that is an absolute piece of automotive art. Thanks Jason for a great video!

[scarringtonzr]

Those engines are epic they were balanced and blueprinted and every engine went on a dyno at the engine plant. To average 175 mph for 24 hours they had to run around 190 mph when you figure the time for pit stops for tires and gas! That was around 4200 miles wide open . I’d like to see someone try that now with a street car!

[jonathanlarsen]

Thanks for bringing back many happy memories. As a young Engineer I organised those durability tests. The CHEVY cycle and the CORP cycle still bring me out in a cold sweat.

[stevethomas]

The drive at the end of the video was icing on the cake. The owner's manual quote was a nice nugget. NSX owner's manual "change from 2nd gear at 81 mph and 3rd gear at 112 mph or you will over rev the engine". I own a '91 NSX. The original owner paid 20K over list, 83K. Certainly ZR1 territory . Used Corvettes are the most bang for the buck you buy in the sport car world.

[troykane]

I owned one of these cars back when they were new. I was an awesome car and could pretty much smoke anything on the road at that point in time. The LT5 engine seemed to have an ability to rev endlessly. For a Corvette it was the ultimate sleeper. Not many people new it was a "special" Corvette. Had a lot of fun with that car.

[interwebdeuce]

I was lucky enough to be a passenger and then be allowed to drive one in the late 90s. My friend's grandfather purchased one before his passing. God bless that man and may he rest in peace. My friend inherited it. And, oh boy, was this thing FAST. No speeding tickets and no accidents. It was truly the first breathtaking car I ever had the pleasure of driving. Even though it was my friend's car he would allow me to drive it from time to time. It was incredible. The video with the engine sound brings back good memories.

[pablocespedes]

I knew almost everything about this Vette, that is because I love this model and read every single bit of info about it, but as usual, Jason and Hagerty kept on feeding us enthusists with more unknown car-data, just like the fact of the radiator place in an angle in order of avoiding those nonsense radars!!! thanks for another good video!

[ZlatkoUnger]

You stop what you're doing when Jason Cammisa comes with another lesson.

[hidaniel]

I never really liked Adam Sandler in movies, but his YT channel rocks. Thank you, Adam.

[bradlangston]

The sound that ZR1 engine makes under full throttle gave me goose bumps! What an awesome achievement at a time when horsepower was in the beginning stages of making a comeback. Kudos to Chevrolet for going that extra mile with the help of Lotus to bring us a thing of beauty!

[jameslonano]

All of these (L98, LT1, LT4, LT5) are still fun to drive. Even my buddies 205 HP crossfire 1984 C4 was a BLAST to drive in the twisty roads in the Pocono mountains.

[daveberg]

I was a GM test driver in 1990-91, in the days when they were testing the C4 Corvettes with the new LT1 engine. One other memory of my time there was how much the engineers enjoyed testing various Porsche cars once in awhile, especially for brake testing. When they were really going to it, tire life was measured in hours, not days or weeks. Of course, there was an on-side fully stocked tire shop, so no worries there. They viewed Porsche as being the pinnacle of braking performance and were anxious to tap any knowledge they could to help the Corvette match or exceed it.

Another memory was the torture testing of transmissions and drivelines as a whole. One test we'd do with various models, not just the Corvette, was to pull up to a painted line, put it in neutral, and run it up to redline. Then we'd drop it in drive until we spun the tires to another line about 10' away, then slam it into reverse, and repeat the process several times over while keeping it at redline the whole time. Personally, I didn't test the Corvette that way that I can recall, but a friend of mine was assigned to a division for awhile where he had to do it over, and over, and over. And each time they did it, they had to pull forward and back 50 times in a row. With the power and traction of the Corvette, he came to despise that car. He said his back would feel like it would going out by the 5th shift, and he knew he still had 45 more to go. Pretty much ruined the car for him, but I always enjoyed the days I was assigned to the Corvette instead of something like a Chevy Citation. A lot of great memories from those days, plus another year after GM when I drove for VW.

[gtoger]

I know it's pretty popular to dump on Corvette (and owners) and especially the C4 these days. We had the opportunity to acquire a ZR-1 at the peak of its unpopularity and have really enjoyed it. The LT5 is a pretty special piece of hardware and has a really unique sound and feel if (like me) you're accustomed to the traditional US V8 experience. Much of the marketing bravado is pretty ridiculous, but that was the age in which the car was born. Even stupider was the marketing and media hype for the 1992 Firehawk which claimed to beat the ZR-1 in almost every respect. Having an example of each car, I'd say that's a bit of a mixed bag.

[campotter]

Excellent synopsis of the ZR-1. A lot of untapped potential in the LT5. Mine has been massaged by former Lotus/Lingenfelter engineer, Graham Behan, and now makes 630hp.