An insightful interview with Zora Arkus-Duntov interview just before he retired.
Dateline: 2.2.21 – To download this PDF E-Book, CLICK HERE –A few months ago at one of our Highlands Corvette Club (Lake Placid FL) monthly Corvette car shows a fellow came up to the sign-in table where I was working and he had a box with several dozen issues of Corvette News from the 1970s.
The June/July 1975 issue had what might have been one of Duntov’s last interviews before retiring as Corvette Chief Engineer. The article starts out, “As we entered his office at Chevrolet Engineering, Zora greeting us warmly…”
What followed is an insightful, warm, eight-page interview with the Godfather of Corvettes.
Enjoy and feel free to share with your Corvette friends. – Scott
Here are the PDF download links to all 4 of the Duntov Files, as of 2.16.21.
Former race car driver, Tom Wallace takes the helm as the new Corvette Chief of Engineering
Dateline: 11-5-20 –During Corvette’s early years, as a result of his racing at Le Mans,Zora Arkus-Duntov got the lion’s share of media attention. Credit also goes to three-time Indy 500 winner and automotive engineer Mauri Rose who helped develop the first Corvette chassis on the shop floor as they were being hand-built in Flint, Michigan. Rose and Duntov were friends but Rose wasn’t impressed with Duntov’s driving and used to say, “Zora couldn’t drive a nail with a hammer.” But by the late 1950s, Duntov was the face of Corvette racing.
We have pointed out that Duntov’s successor, Dave McLellan owned and appreciated sports cars and that Dave Hill raced a Lotus Super 7 in SCCA competition. What most Corvette fans don’t know is that while Tom Wallace had the shortest tenure of all of the Corvette chiefs (2 years and 10 months), he raced SCCA A/Sedan class cars in the early ‘70s and was professionally racing IMSA cars in the late ‘70s and early ‘80s. Wallace raced the 24 Hours of Daytona, the 12 Hours of Sebring, and won at Talladega. Why didn’t Wallace continue professional racing? Because it was interfering with his day job at Buick.
Wallace was a typical car-crazy kid growing up in the ‘50s and ‘60s. His Dad had an Opel Cadet that he kept running with help from a parts donor car. Before Wallace had his driver’s license, he bought a ’55 Chevy, replaced the stock 3-speed transmission with a 4-speed, rebuilt the engine, and added dual quads. After getting his license, he had the quickest car in high school and rarely lost a drag race.
Thanks to his excellent grades, Wallace went to General Motors Institute after securing a sponsor to become an automotive engineer. Wallace wanted to get into Chevrolet, but there were no openings, so he opted for Buick. One of his first projects was the design and development of the Exhaust Gas Recirculation (EGR) valve that siphons off a small amount of exhaust gas and returns it back into the intake charge. This results in lower nitrogen oxide (NOx) emissions.
Wallace graduated in 1970 just as the muscle car era peaked and was ending. Performance was being phased out and emissions, fuel mileage, and safety were Detroit’s new mission. Lloyd Reuss, Buick’s chief engineer was aware of Wallace’s interest in racing and asked him to research adding a turbocharger to their old V6 engine. Wallace’s reported that it could be done and Reuss instructed him to install a turbo on a Buick Century to pace the 1976 Indy 500. As part of a three-man team, Wallace was the engineman, the others did the suspension and brakes. In total Wallace produced six Indy 500 pace cars. Wallace’s turbo Buick V6 project eventually lead to the Buick Grand National, Turbo-T, T-Type, and the frightful GNX series cars that ran from 1982 to 1987.
Wallace enjoyed engineering and racing, but he knew that if he was to rise up in the ranks in GM, he needed to curtail his racing and get more education. In the early ‘80s Wallace got his Masters in Business at Stanford and over the next twenty years had a variety of chief positions with Buick, Olds, Cadillac, and Chevrolet groups. When GM started its Vehicle Line Engineer (VLE) management structure, managers were in charge of everything from design-to-production, sales, and service. Wallace ran the Trail Blazer, Envoy, Bravada, Saab 9-7, Colorado/Canyon pickups, and the Hummer H3 lines.
Dave Hill was the VLE of Performance Car that included Corvette, Cadillac XLR, Saturn Sky, Pontiac Solstice, Opel GT. One day during a group vehicle-program review meeting with Bob Lutz; Wallace heard Hill outlining the Z06 with 505-horsepower and a dry-sump oil system, he said to himself, “What the!” Wallace said to Lutz, “My goodness, this is unbelievable. Do you know what Dave is about to do?” Wallace said that some of the VLEs had no idea what Hill was talking about. When Wallace expressed real concern about selling 505-horsepower cars to novice customers, it was explained to him that only select dealers get Z06s. These dealers understand performance and coach customers to have respect for the car and help get them into a driver’s school.
Late in 2005 Wallace got the surprise of his career. After a VLE meeting, Lutz told Wallace that Hill was retiring on January 1 and that he wanted him to take the position of VLE and Chief Engineer for Corvette. Wallace was stunned and fully aware that he was inheriting a great team with Tadge Juechter as his lead engineer. But unforeseen circumstances would make this a short-lived position – only two years and ten months.
When Wallace took over the Corvette program, the C6 ZR1 was a concept on paper and was deemed too expensive. Wallace and his team worked out the cost, got the project approved, and started the ZR1’s development. It wasn’t long before rumors of a super Vette surfaced with names such as “Blue Devil” and “SS”. Then someone inside GM posted a photo of a development ZR1 as it was being shipped to Germany for testing. The Corvette world knew for sure when a cell phone video was posted of a disguised Corvette with the unmistakable sound of a supercharged engine. WOW, a supercharged Corvette!
When the ZR1 was released to the press in late 2007, Wallace explained, “We want to push the technology envelope into the supercar realm. We want a Corvette that can take on any production car in the world.” While Corvette fans were feasting, GM was heading for bankruptcy. Corvettes had a history of platforms running too long. Hill said that the planned six-year duration might even be too long. Wallace and his team started work on the C7 in April 2006. As things got worse for GM, it was discovered that the only full-size trucks and Corvettes were moneymakers. Regardless, future plans had to be stopped.
In October Lutz informed Wallace that the board of directors did not approve funding for the C7, he would have to proceed with paint and decals for the foreseeable future. Also, to preserve cash, top-level executives were offered early retirement to reduce headcount. For a car guy/racer, babysitting the Corvette was not how Wallace wanted to end his GM career, so he retired on November 1, 2008.
Wallace didn’t get to do as much with the Corvette as he wanted, but he did several things that made a difference. He knew that it would be very beneficial for his engineers to get track training at the National Corvette Museum’s and to talk with customers about what they like, don’t like, and want for future Corvettes. As Wallace had expressed concerns over selling powerful Corvettes, included in the price of the ZR1 was high-performance driver training. And with his racing background, Wallace was the perfect lead engineer to work with Pratt & Miller on issues with their C6.R cars. This intense relationship caused more racecar to be built into the C7. While Wallace wasn’t able to usher in the C7, his efforts set up the program for the capable hands of Tadge Juechter. – Scott
PS – Be sure to catch all 5 parts of my Corvette Chiefs Series
Duntov carried the heart and soul of the Corvette into racing and created an American legend.
(Dateline: 7-3-20 – This story was originally published in the now-defunct Vette magazine, June 2019 issue) Arguably, there had never been a chief engineer of an American car the likes of Zora Arkus-Duntov. When Duntov was hired to work at Chevrolet on May 1, 1953, the 43-year old European-trained engineer brought a background that made him uniquely qualified to become Corvette’s first chief engineer.
As a young man, Duntov was into boxing, motorcycles, fast cars, and pretty girls. After his formal engineering training in Berlin, Germany, Duntov started racing cars and applying his engineering skills to racecar construction. In 1935 Duntov built his first racecar with help from his racing partner Asia Orley; they called the car, “Arkus”. Their goal was to debut the car at the Grand Prix de Picardie in June 1935. But after a series of mishaps, the car caught fire and never raced. From this point forward, all Duntov wanted to do was build racecars.
In the 1930s Auto Union and Mercedes built the best racecars in Europe. Duntov wrote a technical paper about a new racing concept for the German Society of Engineers titled “Analysis of Four-Wheel Drive for Racing Cars”. at the 1937 Automobile Salon in Paris, Duntov met Dr. Ferdinand Porsche, the designer of the Mercedes-Benz SS and SSK racers, and French performance-car builder and designer, Ettore Bugatti. Mercedes-Benz cars were complex engineering marvels, but Duntov appreciated Bugatti’s elegant simplicity, raw speed, and the success of his cars with privateers. “Simplicity and privateers” are two hints of things Duntov would later do with Corvettes.
After marrying Elfi Wolff in 1939, war broke out in Europe, and Duntov and his brother Yura had a brief stint in the French air force. France fell quickly and Duntov and his family made their way to New York. The brothers setup the Ardun Mechanical Corporation and worked through the war years as parts suppliers for the U.S. military. After the war Duntov and Yura turned their attention back to racecars and started producing their Ardun Hemi Head Conversion kits for flathead Fords.
Post-war years were difficult and by the early ‘50s Duntov was looking for an engineering job with a major Detroit car company. His goal was to find a company that would let him build racecars. When Duntov saw the first Corvette at the 1953 Motorama, he immediately pursued GM, specifically to work on the new Corvette. Chevrolet general manager Ed Cole hired Duntov and assigned him to work under GM suspension master, Maurice Olley; the clash was immediate. Olley was reserved and a numbers-cruncher; Duntov was outgoing and designed by intuition. Six weeks after being hired, Duntov requested time-off to race a Cadillac-powered Allard JR at The 24 Hours of Le Mans. Olley refused, but Cole got him off the hook to race at Le Mans, but without pay. Duntov was so irritated that he almost didn’t come back from France.After his return, Duntov reassigned and started testing special parts to improve the Corvette’s suspension and general performance.
When the 265 small-block became available in 1955, Duntov took a modified ’54 Corvette with the new engine and some aero mods to the GM Phoenix Arizona test track where he was clocked at 162-mph. The mule Corvette was later rebodied as a ’56 Corvette and was part of a team of three Corvettes that were taken to the 1956 Speed Weeks event at Daytona Beach where Corvettes set speed records. Then in March at the 1956 12 Hours of Sebring race, Corvette scored its first major class win. Duntov and three-time Indy 500 winner and engineer Mauri Rose were then tasked by Ed Cole to design, develop, and make available, special Chevrolet-engineered racing parts. When the Rochester Fuel Injection option was released in 1957, RPO 684 Heavy-Duty Racing Suspension was there for privateers that wanted to race their Corvette.
The Bugatti pattern was laid down; make simple, fast cars, and let the privateers do the racing. Duntov also built a few purpose-built Corvette racecars. The 1957 Corvette SS was a good first step but the timing was bad because of the 1957 AMA Racing Ban. The Grand Sport was similar to the RPO Racer Kit program, only a complete, basic racing Corvette was to be sold to privateers. Again, the AMA Racing Ban killed the project. If Duntov hadn’t pushed racing, the Corvette would have morphed into a Thunderbird-like four-seater and been killed by the early ‘60s.
Duntov laid out three design concepts that took decades to implement. The first was his proposal for the 1957 Q-Corvette. This design called for the following: an all-aluminum, fuel-injected small-block engine, four-wheel independent suspension, four-wheel disc brakes, and a transaxle. This design concept arrived in 1997 as the C5.
The second design concept was the mid-engine layout. Duntov’s first mid-engine concept was the 1960 CERV-I. The design parameters were those of an Indy 500 racecar, but with a larger engine. Duntov’s second mid-engine car was the 1964 CERV-II. The third concept in the CERV-II was its unique four-wheel-drive system. Using transaxle parts from the Pontiac Tempest, the system “worked” but would not have lasted as a racecar.
Through the ‘60s several other mid-engine “Corvette” cars were built, but not by Duntov. Engineer Frank Winchell’s 1968 Astro-II Corvette was a beautiful attempt, but like all mid-engine Corvette proposals, it went nowhere. In 1970 Duntov showed his XP-882 with a transverse-mounted 454 engine. After the car was shown at the 1970 New York Auto Show, it went into hiding for some reason. Later, the chassis was used to build the Four-Rotor mid-engine Corvette that was later retrofitted with a small-block engine and rebranded “Astrovette” in 1976, after Duntov retired.
Just after the debut of the C7, the Corvette community started buzzing about the mid-engine C8. For a time the C8 was an unconfirmed rumor until Chevrolet announced that, yes, a mid-engine Corvette was in the works. In 2018 camouflaged mule cars started being seen on public roads. In July 2018 a camouflaged C8.R was seen being tested. Towards the end of 2018 speculation was that the C8 would debut at the 2019 Detroit Auto Show. Then in December 2018, Chevrolet announced that the C8 would be delayed “at least six months” due to “serious electrical problems.”
An insider friend has been telling me for over a year that they were having serious problems getting the car right, but he wasn’t specific. Then another hint was dropped; the problem is with the car’s 48-volt electrical system. Why would the C8 have a 48-volt system? Answer; because it will have auxiliary electrical front-wheel drive. Suspension and traction is everything, so AWD is inevitable.
While Duntov didn’t “predict” the Corvette’s future, he certainly set the course. His insistence that Corvette be tied to racing, kept the car from becoming Chevy’s Thunderbird. The features of the 1957 Q-Corvette are the very design foundation of the C5, C6, and C7 Corvette. The CERV I, CERV II, and the XP-882 (minus the transverse engine) will live in the mid-engine C8. And it is likely that the CERV II’s all-wheel-drive concept will live in the C8, only as an electrical, and not a mechanical system. Without one man’s obsession with building racecars, there’d be no Corvette legend. – Scott
Be sure to check out the Duntov installment of my “Founding Fathers, Pt. 4 Zora Arkus-Duntov”, HERE.
Also, catch all 5 parts of my Corvette Chiefs Series
Jim Perkins: The Man That Saved the Modern Corvette
(Note: this story was originally published in the March 2019 issue of Vette Vues Magazine) – The Corvette is the most unlikely of all cars for a company such as General Motors to produce. GM is all about producing huge volumes of cars and trucks. When the Corvette came out as a late offering in June 1953, only 300 cars were hand-assembled. Engineers and builders were literally designing as they were building the cars. Sales jumped to 3,640 for 1954 and tanked to just 700 in 1955. Harley Earl restyled the Corvette for 1956 and sales went up to 3,467 units and then 6,339 for 1957. Meanwhile Ford sold 16,155 T-Birds in 1955, 15,631 in 1956, and 21,380 in 1957! They were killing the Corvette then went to a four-seater configuration, leaving Chevrolet the two-seater sports car market all to themselves. Corvette sales didn’t hit 10,000 units until 1960; not much in the big picture of GM!
The long knives were out for the Corvette inside GM. There were many that didn’t understand the Corvette, didn’t like it, and wanted it dead! What saved the Corvette were its corporate angels; Art and Color Section VP, Harley Earl; Chevrolet general manager, Ed Cole; Senior VP of Design, Bill Mitchell; Zora Arkus-Duntov; and Mauri Rose. The common denominator with all of these men is that they are “car guys”. Bill Mitchell was famous for boasting, “I’ve got gasoline in my veins!” Aside from Duntov and Rose, these men had corporate clout; they could lean on and make things happen.
In 1960, after some college attendance at Baylor University and three years in the Navy, Jim Perkins took a job at a Chevrolet warehouse, sorting parts while he finished his degree. Little did Perkins know that thirty years later, he too would become a corporate angel for the Corvette.
Perkins was a Depression Era kid from Waco, Texas. When World War II broke out Perkins’ dad tried to enlist in the military but was told he was “too old”. This was a time when men did whatever they had to do to put food on the table. Being mechanically inclined, Perkins’ dad started fixing cars, then buying, and selling cars. Perkins spent a lot of time with his dad and at the age of 14, he got an after school job at a local Texaco service station. Perkins quickly developed a reputation as a very good Chevy mechanic. Perkins fixed and sold a series of cars and finally got a hot ’52 Oldsmobile. But when the ’55 Chevy came out, he sold his Olds and made enough for a new Chevy. From here forward, Perkins was a Chevy car guy!
After graduating from high school, Perkins took courses at Baylor then served three years in the Navy. After his discharge from the Navy, he took a low-level job, sorting parts at a Chevrolet warehouse, while completing his college courses. With his Navy experience and eventual degree, Perkins quickly rose through the ranks at Chevrolet in Sales & Service. In the mid-‘70s, he landed a peach-of-a-job working for then GM president, Pete Estes. That’s where Perkins learned the ropes of GM corporate life.
After a few years working for Estes, Perkins was transferred to Buick. Detroit was struggling to come out of the 1970s recession and how to deal with the success of Japanese cars. Perkins was working under Lloyd Reuss and it was a good relationship. “Just In Time” production was a new concept and Perkins was doing many of the management tasks that Lloyd normally would have done, and he loved it! The first two years they set records; then management changed.
The new top guy at Buick was Don Hackworth and it wasn’t a good mix for Perkins. The two men almost immediately started butting heads. On a plane coming back from a business meeting, Perkins asked Hackworth what they could do to have a better working relationship. Hackworth suggested a “foreign assignment” for Perkins. That was IT for Perkins. What Hackworth didn’t know was that Toyota was wooing Perkins for an executive position. The timing was perfect
When Perkins came into Toyota with his “GM top-down” management style, he was nearly stopped in his tracks. The Japanese car companies were all using the “Consensus Process”; which starts from the bottom (assembly workers) and goes up from there. Perkins quickly learned that while the process takes longer, the execution is like a rocket ship; everyone is onboard and you get better solutions.
A year later, Toyota made Perkins Group V.P. for Sales, Marketing, Distribution, Product Planning, and New Ventures. Around this time Japanese car companies announced that they were taking on the luxury car segment of Mercedes and BMW. Mr. Toyoda wanted to prove to the world that they could build world-class luxury automobiles. Toyota formed Lexus and Perkins was a key player.
Then, an extraordinary thing happened; GM wanted Perkins back! Typically at GM, once you leave, that’s it. Perkins learned from his former boss, Lloyd Reuss, that then-GM president Bob Stemple (another car guy!) wanted to talk to Perkins about coming back. When the two men talked, Perkins told Stemple, “There are two jobs I would come back for; president of GM, or general manager of Chevrolet.” Stemple’s reply was, “Well, that’s a little lofty.” Stemple and Perkins continued their conversation for a time before Stemple called Perkins. “OK, big boy, it’s time to put up of shut up. We’ll make you general manager of Chevrolet.”
It had been twenty-nine years since car guy mechanic Jim Perkins started sorting parts in a Chevrolet warehouse. In May 1989 Perkins was made general manager of Chevrolet. He’s always been a Chevy-guy, and now he was running the division. But when Perkins got back, he was in for a shock. Perkins said in a 2014 interview with Motor Trend, “I didn’t recognize Chevrolet when I got back. It had lost its pride. There was so much infighting among sales, marketing, product planning, distribution, you name it. Everywhere you looked was a silo with its own management, and that’s the kiss of death.”
“TCE” Total Customer Enthusiasm had to start at the top, meaning that managers with bad attitudes had to go. Using Toyota’s “Consensus Process” concept, Perkins invited his people to write to him about the problems they faced and possible solutions. Perkins got 1900 letters, read them all, distilled them into to-do lists, and formed employee councils to come up with working plans. A lot got fixed, workers felt their experience mattered and the organization was much happier. The same concept was also applied to the dealer networks.
By 1990 the nation’s economy was moving into another recession and things were not good inside GM. All car lines were being closely reviewed and Corvette sales were in a downward direction. Once again, the car was on the chopping block. According to Corvette designer, John Cafaro, by 1992 the Corvette almost died. People in the company didn’t understand the car and no one wanted to champion the car. Former GM executive Ralph Kramer said, “Many GM insiders considered the Corvette to be a non-essential product in the GM/Chevrolet stable. The thought that the Corvette would NOT just be in the Chevy stable of cars, but instead the main character; the stud-horse; the Secretariat; was totally remote to the Corvette-haters; but how could it not be otherwise?” (Today, the Corvette is THE flagship of GM)
GM’s Mid-size Car Division managed Joe Spielman (also a car guy and Corvette fan) created a task group called, “The Decision Makers”. The group consisted of himself, Carlisle Davis, John Cafaro, and Dave McLellan. The team’s objective was to create a path for the future of the Corvette. They came up with three directions; First: A production version of the 1990 mid-engine CERV-III; Second: The Momentum Architecture, featuring an evolutionary body style, a stiff backbone-type chassis, and a transaxle; and Third: the “Stiffer and Lighter” design which was a lighter and improved C4. The team chose the “Momentum Architecture”. The problem was funding.
In November 1992 Dave Hill took over as Corvette’s chief engineer and had a big problem on his hands; how to prove the concept of the Momentum Architecture when he had no budget. Corvette manager Russ McLean went the Perkins and explained that the Corvette team needed funding for another CERV Corvette (Corporate Engineering Research Vehicle) to prove the viability of the Momentum Architecture concept. Perkins managed to pull $1.2 Million from another budget to allow Hill’s team to build what is arguably the stealthiest R&D Corvette ever, the CERV IV.
The CERV IV was essentially a C5 structure wearing a C4 body. A keen eye would have noticed that it looked like a “l-o-n-g” C4 Corvette, but when the car was on public roads, no one noticed. When Hill took executives for a ride, they all said, “This is like no Corvette we ever felt!” Hill proved to GM’s president, Jack Smith, that his team could reinvent the Corvette, as well as the building process. The $1.2 Million that corporate angel Perkins was able to secure for the CERV IV saved the Corvette! It was something that ONLY Jim Perkins could have done.
In 1996, at age 61, Perkins retired from Chevrolet. In his seven years as Chevrolet’s general manager he rekindled Chevy’s 1960’s-style pride; improved Chevy’s truck production; strengthened Chevy’s role in product development and design; helped his people come to grips with downsizing and reorganization, supervised the Chevrolet Racing Team that won five NASCAR Championships and had six Indy Car victories; and got to drive the pace car at the Indy 500 three times in 1990, 1993, and 1995 (in a Corvette).
In the 2014 Motor Trend interview, Perkins said this about driving the Indy pace car, “You come out of turn four when you’re going to turn them loose, you know you have to make the left turn into the pits, you look down the track, and it looks like everything is closing in on you with all the people and color and movement. You swear you’re going through the eye of a needle. My God, it is such a tremendous, tremendous experience.”
Retirement from Chevrolet only lasted three months when Perkins accepted an offer from Rick Hendricks to take over his company after he came down with leukemia. Perkins stayed on as the CEO and later COO. Perkins said of his time at Hendricks Motorsports, “If ever anything has been rewarding, it has been seeing this company do what it has done. I have no regrets. It’s been a blast, a great, great, great ride.” In 1999 Jim Perkins was inducted into the National Corvette Museum’s Hall of Fame in the GM-Chevrolet Category.
Jim Perkins was a poor kid from depression-era Waco, Texas that liked to work on Chevys. He was described as a “wily, free-speaking, cowboy boot-wearing Texan.” Perkins died on December 28, 2019 in Charlotte, North Carolina. Jim Perkins was 83 years-of-age. Perkins had an exemplary career and most importantly to the Corvette community, saved the Corvette. – Scott
Dateline: 1-20-20, Illustrations & graphics by K. Scott Teeters – The C6 Corvette was a much-improved C5 and was well-received upon release. Fans liked the crisp new look, the new interior (for a while), and the extra grunt. Since the successful arrival of the performance Z06 model in 2001, every new generation Corvette is expected to have a Z06. Within minutes of the C6’s debut, the next question was, “Where’s the Z06?” The following year when the C6 Z06 was unleashed, there was an unanticipated surprise; an aluminum chassis.
This wasn’t on anyone’s wish list and was a total surprise. It wasn’t even on Zora Arkus-Duntov’s Christmas list! Weighing in at just 3,132-pounds, you have to go back to 1964 to find a lighter Corvette (3,125-pounds). Powered by the mighty 427 LS7 engine with 505 net-horsepower, with C5-R suspension technology, the C6 Z06 was better suited for the track, although many learned how to drive the new beast successfully on the street. The C6 Z06’s aluminum chassis had no trouble handling 638-horsepower in the ZR1 configuration. Bravo Corvette chassis engineers!
When Tadge Juechter’s C7 Corvette debuted, fans were stunned to learn that the base model C7 was built an even better version of the Z06’s aluminum chassis. But wait, there’s more! The same new aluminum chassis would be used for the coupe AND convertible Corvette. This was a major breakthrough and bespeaks of advanced engineering. Here’s how Juechter’s team did it.
Juechter’s objective was to build a modern performance car that delivered enhanced driving experience, more efficiency that yielded more performance. Every element had to contribute to the overall performance and there would be nothing fake. That explains everything that we see on the C7 Corvette, but what’s unseen is even more amazing.
As we learned from the C5 with its hydroformed side rails, stiffness matters. Juechter is on record stating that while hydroforming was an engineering game-changer, the downside is that parts have a uniform thickness; even in areas where it isn’t needed. Hydroformed parts cannot be tailored for areas that need greater or less strength. Enter the Genesis Software Program.
This is almost computer magic. Engineers first determine the overall block space they want; length, width, and height. Then they determine where they want to place the major components; engine, transmission, suspension assemblies, cabin parts, etc. This creates negative spaces where the structure needs to be to hold everything together. The Genesis Program then synthesizes an optimum structure so that engineers can then take the load design and break it down into parts that can be fabricated and joined together. Afterward, dynamic stress and crash testing is performed and parts modified to meet predetermined objectives.
The C7’s hydroformed aluminum frame rails were optimized for the best the aluminum industry could offer, in terms of tensile strength, lightweight, and materials-joining technology. New aluminum metallurgy and aluminum fastening technologies allow engineers to augment the hydroformed frame with 7000-Series aluminum extrusions designed for specific areas; such as engine/front suspension assembly, transaxle/rear suspension assembly mounting points and frontal collision areas.
Careful consideration to the placement of major components was also critical. Juechter’s team felt that the C6 was slightly nose-heavy. Components were adjusted so that the C7 is now rear-biased, allowing more load on the rear wheels for better traction at launch; like a racecar. The front wheels were moved forward 1-inch making the wheelbase 106.7-inches. This is the longest wheelbase Corvette ever made. The shortest was the C4, measuring 96.2-inches. Moving the wheels forward also allowed for more space under the hood for the new LT1 engine and various auxiliary systems. This also preserved “crash space” in the front.
Offering an aluminum frame for the coupe and convertible was a big challenge for the team. But because the basic frame structure is so strong, it didn’t need additional roof structure via a fixed roof. The net result is that not only can the Z06 and ZR1 have lift-off rood panels, but both can also be offered as a convertible. This was unimaginable for the C5 Z06, C6 Z06, and the C6 ZR1. According to Ed Moss, the C7 structural engineer group manager, his engineering team tailored sixteen different thicknesses of various grades of aluminum from 11-mm to 2-mm. The completed C7 aluminum frame is 100-pounds lighter than the C6’s steel frame and is 60-percent stiffer. Juechter said that engineers consider the C7’s aluminum chassis to be the most beautiful part of the C7. Perhaps someday Chevrolet will offer a transparent carbon fiber body option.
The C7 frame was also designed for aerodynamic efficiency. In the past, engineers tended to only consider how air passed over and under a performance car. The C7 literally breathes. Spaces under the car’s skin and in between the chassis structure were designed for the internal ducting for engine cooling, brakes, transmission, and differential cooling, and venting. Other spaces allowed for electrical and plumbing fixtures for coolant, fuel, and air conditioning ducting.
The C7 design team worked closely with the Corvette Racing Team on airflow management because even racecars are concerned about fuel consumption, as well as top speed dynamics and stability. Two of the most obvious ducting and venting features is the air extractor on the hood, and the NACA ducts on the top of the rear fenders.
Taking a lesson from the C6.R Corvette racecars, the C7’s radiator is tilted forward. One-third of the air that passes through the radiator is vented out of the hood. The hood louvers are angled so that the exiting air flows tightly over the car creating additional downforce to the nose of the car; thus eliminating the dreaded nose lift.
Heat exchangers (radiators) for the transmission were placed in the back, close to the transaxle with air ducted through the NACA duct feeding into the heat exchangers and then vented out through vents next to the taillights. This is just another example of how every element on the C7 has a defined purpose.
All of the foundational work that went into the C7’s chassis laid down a structure what was easily adaptable to the $2,780 Z51 suspension option that included; performance brakes with slotted rotors; dry-sump oil system; suspension upgrades; special wheels and tires; electronic limited-slip differential with a cooler, performance gearing, and an aero package. The Z51 was for drivers that wanted to use more of the C7 460-horsepower and explore the pleasures of the C7’s superior structure.
The 2015 Z06 with its supercharged 650-horsepower LT4 engine, wide-body, suspension, and tire enhancements work wonderfully with the C7’s basic structure. The same can be said for the 755-horsepower ZR1; the basic structure is up to the task. Arguably, the most interesting use of available C7 components is the Grand Sport. It has the aggressive-looking Z06 body and suspension parts that take using the base model’s 460-horsepower to a whole new level.
I will now go out on a limb. At the C7 ZR1 debut in 2018, Juechter said that his engineers had taken the C7 as far as they could with the ZR1. Are they working on a C9 Corvette to sell alongside the mid-engine C8? If so, will it be built on a carbon fiber chassis? When it comes to Corvettes, things always evolve upward. – Scott
After 20 years of use, the C2/C3 Corvette chassis was finally replaced with a strong, lightweight, vastly improved chassis and structure.
Dateline: 8.9.19 – Illustrations from GM Archives, Grahics by K. Scott Teeters –The C2/C3 chassis had an amazing 20-year production run. When Dave McLellan took over as Corvette’s chief engineer in 1975, the Corvette was overdue for a redesign. The only good thing about the 1970s was that Corvettes sold very well. On January 22, 1979 McLellan received approval to start designing the C4 Corvette.
One of the C3’s endearing features was the T-top roof. The design wasn’t just for aesthetics; the T-bar connected the A-pillar windshield frame to the B-pillar frame “roll bar” and provided significant structural stiffness. The initial design of the C4 had a T-bar connecting the A and B-pillars, but with a one-piece, roof panel. It wasn’t until the first prototype was built in 1981, when Chevrolet general manager Lloyd Reuss made the decision to eliminate the T-bar to open up the cockpit. This single decision impacted the C4 design such that the biggest complaint about C4s is the tall side frame sills that make ingress and egress challenging. To compensate for the lack of the important T-bar, the side frame sills had to be made extra tall. As the years rolled by, C4s, especially the convertibles, took heat for not being as stiff as their competitors. Those two elements, plus the fact that progressive Corvettes kept getting better and better, are part of the reason why C4s are today the least desirable of all Corvettes.
McLellan’s engineers had two overriding design elements; first, they wanted a lower overall height; and second; they wanted more ground clearance. McLellan’s team started placing the big pieces in a process they called, “stacking”. Starting at the ground level, the engine had to be lower to improve forward visibility. Previous Corvettes had been two-part cars; a body bolted on to a chassis. But the C4 was a three-piece car, which included, a chassis, a birdcage, and a body. This created a more integrated body and stronger configuration.
The C4’s parameter frame was built from 18 pieces of stamped and boxed high-strength steel that included the tall side sills, the front sides, the rear sides, four crossmembers and braces. All of the pieces were put together in a jig and welded together. The birdcage section included the forward door jams, the dash crossmember, the A-pillar, the rear section of the floor pan, and the B-pillar. The completed birdcage was then welded to the parameter frame. An aluminized steel engine and front suspension cradle positioned the engines and provided mounting points for the front suspension. The rear section of the frame was aluminum and provided mounting points for the rear suspension and rear bumper.
Unlike the previous chassis’ that had the engine, transmission, and suspension simply bolted to the frame, the C4 used a steel driveline support that was bolted to the rear of the transmission and connected to the rear differential that housed the driveshaft. By doing this, all of the components became stress members of the chassis structure.
Thanks to the C4 Corvette’s unique clamshell hood, Corvette owners got to see more of their front suspension than ever. Gone were the days of heavy stamped steel upper and lower A-arms. The C4’s front A-arms and spindles were slender, computer-designed forged aluminum. The C4 suspension used composite leaf springs on the front and rear suspension. Don’t let the term “leaf spring” throw you. These are computer-engineered, high-tech, lightweight suspension parts. A composite fiberglass monoleaf spring was first used in 1981.
To download a PDF version of the 1984 Corvette brochure, CLICK HERE.
To download a PDF version of the 1984 Corvette brochure, CLICK HERE.
C4’s multi-link rear suspension eliminated the C2/C3 rear end “squat” upon hard acceleration. This setup uses upper and lower control rods that connect the wheel bearing yolks to brackets mounted to the vertical section of the of the rear of the frame. Each bearing yolk has support rods that tie it to the rear differential. Today when we look at C4 Corvettes, especially tired old examples, the frame and suspension looks somewhat crude and outdated. However, C4 suspensions are regularly harvested from salvage yards, cleaned up, and refreshed for street rods.
From the perspective of the C4 Corvette’s November 30, December 1, 1982 press debut, the car was a total “WOW!” The cover story of the March 1983 issue of Road & Track was “Corvette Spectacular!” The debut wasn’t unlike the debut of the C6 and C7 Grand Sport Corvettes, in that with virtually the same horsepower, teamed with a much better suspension (the Z06 on the C6 and C7 GS), the car is vastly improved. Automotive journalists were blown away by how tight and solid the new C4 was. But it was the skidpad performance that astounded everyone. Z51 examples had no trouble hitting 0.95g on the pad, and one Z51 with slightly wider front tires scored a 1.01g! Ferrari’s $80,000 512 Boxer could only generate 0.86g, and Richard Petty’s Grand National Stock Car scored 1.04g. The March 1983 issue of Popular Mechanics proclaimed, “1983 Corvette: Best American Car Ever!”
Bowling Green started the 1984 season early and consequently racked up the second-best ever sales season with 51,547 Corvettes sold. Media hype totally stoked Corvette fans for the Z51, such that 50.4-percent of all 1984 Corvettes were ordered with the $600 Z51 option. Then reality set in. On real roads the ride was for many unbearable, in fact, many owners of regular 1984 Corvettes weren’t happy with the ride quality. Corvette engineers acknowledged that they had “over-done-it” on the suspension.
For 1985 engineers softened the front springs by 26-percent in the front and 25-percent in the rear. Z51 springs were softened 16-percent in the front and 25-percent in the rear with larger stabilizer bars. 1985 also saw the return of a full-fledged fuel-injection system with the introduction of the L98 that had a 25-horsepower bump that made the Corvette, according to Car and Driver, “The Fastest Car In America”. It was also the beginning of a three-year romp by Corvettes in the SCCA Showroom Stock Series. Corvettes so dominated the series they were kicked out in 1988 and Porsche bought a C4 Corvette to learn why the car was so fast.
But as power started to nudge up and tires got wider, the inherent design flaw with the C4’s lack of a T-bar was more obvious, especially on the convertibles; even with a bolt-on X-brace on the bottom of the chassis that raised the ride height 10mm. Since there are so many C4 Corvettes out there that few want, unless the car is a special edition or a pace car, you can do almost anything to a C4 and never get any heat. I learned from the C4 forums that many C4 owners that are hot rodding their cars use the factory X-brace and frame torsion rods to stiffen the structure of their car. Makes sense if you are adding a lot more power and bigger tires.
The C4 had a long run of 13-years. Towards the end of McLellan’s tenure as Chief Engineer in the early 1990s, he pushed for the C5, but GM was having money trouble and was in no mood for a new Corvette. In fact, they were considering eliminating the Corvette. By September 1992, McLellan retired and the following month, Dave Hill was the new Corvette Chief Engineer. The C5 Corvette would be Hill’s to design.– Scott
Dateline: 7.31.19 – As seen in the January 2019 issue of Vette magazine, Illustrations by K. Scott Teeters – When the 1963 Sting Ray made its public debut in September 1962, it was a total, “WOW!” And it wasn’t just the Corvette’s stunning new looks; it was the all-new chassis and suspension. By late 1959 Zora Arkus-Duntov was in charge of Corvette engineering. When Bill Mitchell’s design team started work on project XP-720 (the all-new Sting Ray), Duntov was called in to set the parameters for an all-new chassis. The completed Sting Ray looked like the sportscar from another planet and the chassis had everything except four-wheel disc brakes. Today the running chassis looks like a buggy compared to the stout aluminum, steel, and magnesium chassis’ of the C5, C6, and C7 Corvettes. But in 1963 the top-performing L84 Fuelie engine only had 360 “gross” horsepower and 352-LB/FT of torque putting power-to-the-ground with 6.70×15 bias-ply tires. That’s not much twisting on the chassis, so the chassis was more than adequate.
Even when the high-torque big-blocks arrived in 1965, for street use, the Duntov chassis could handle the job. The design didn’t start to show its limitations until the 1968 L88 racing Corvettes with wide tires started competing in long endurance races. Tony DeLorenzo once commented that after long 12 or 24-hour races, their Corvettes needed new frames. Their solution to this problem was a Logghe Brothers full welded-in roll cage. Greenwood’s wide-body Corvettes were so reinforced many asked, “Is there still a Corvette in there?” But for street use and spirited driving, the Duntov chassis served the Corvette well until 1982. Lets look at the chassis’ basics to see why it lasted so long
The genius of Duntov’s chassis was how much lower the center of gravity was. Chevrolet engineer Maurice Olley was a production car chassis and suspension expert when he designed the C1 chassis. As a racing expert, Duntov knew he had to get the center of gravity much lower. The C1’s chassis had a parameter frame with x-bracing in the center for rigidity. The car’s occupants sat on top of the frame. Everything measured from there; the cowl height, engine height, and everything else.
Duntov’s design eliminated the x-brace so that the occupants could be placed down inside the frame, dramatically lowering every data point from there. For rigidity the new frame had five crossmembers. Duntov then mounted the engine and transmission as low and as far back as possible and routed the exhaust pipes through holes in the second frame crossmember. The passenger compartment was pushed back as far as possible and the spare tire was mounted below the back of the frame and under the fuel tank.
The lowering of the engine/transmission and passenger compartment lowered the center-of-gravity from 19.8-inches to 16.5-inches. Moving major components as far back as possible in the shorter 98-inch wheelbase created a front/rear weight distribution of 47/53-percent. The engine centerline was offset 1-inch towards the passenger side because passenger footwell requirements were less than the driver’s. The extra offset reduced the transmission tunnel width and allowed the crankshaft and rear axle pinion to be on the same centerline. Ground clearance was just five-inches.
The build of the frame used boxed longitudinal sides with five crossmembers that were designed to suit the needs of styling. The new frame actually received computer analysis to determine the thickness needed for the parameters of the overall car. The front crossmember was welded to the sides and not bolted-on like the C1 chassis. The new frame with mounting brackets weighed 260-pounds, the same as the C1’s frame, but torsion rigidity increased from 1,587 lb/ft to 2,374 lb/ft per degree.
The C2/C3 suspension was a parts-bin marvel, although it didn’t seem that way. Duntov wanted an independent rear suspension and was immediately told, “No! It’s too expensive.” To get around this, Duntov used almost 60 full-size passenger car front suspension parts, including pressed-steel wishbones and ball-jointed spindles, and just rearranged them. The parts had already been engineered and proven, thus saving production cost. With a 9-degree slope, the wishbones gave an anti-dive reaction upon heavy braking. Then the inner pivot points were lowered to raise the roll-center to 3.25-inches above the ground. A recirculating-ball steering unit was placed behind the suspension and used a hydraulic damper to reduce kickback. All of these changes were very apparent when combined with the right shocks and anti-roll bars when the cars were first driven and tested. The money saved was more than what went into the rear suspension.
The independent rear suspension started with the differential pumpkin bolted to the 4th crossmember with the driveshaft as a device to control forward thrust from the wheels. Axle half-shafts with universal joints are on each side of the differential. Steel box-section control-arms carry the outer half-shafts and attach to the rear frame kickup assembly. Shims at the forward pivot-points are used to adjust toe-in alignment. Strut rods attach to the strut-rod bracket bolted below the differential and connect to the rear spindle support on the control-arms. The nine-leaf transverse spring with polyethylene liners between each leaf to reduce noise, mounts under the differential and is sprung against the rear portion of the control arm with long bolts. Duntov’s proposal to use a transverse leaf spring was not well received by Chevrolet chief engineer, Harry Barr, but no one could come up with a better plan.
For its time, Duntov’s chassis worked very well, but I’m sure that no one imagined it would be used for 20 years. The design proved to be easy to update. Disc brakes were in development when the Sting Ray came out and arrived on the 1965 model. When the new Mark IV became available in 1965 the suspension got stiffer front springs and larger diameter front and rear stabilizer bars. The new chassis was totally adaptable and could be made near-battle-ready with suspension component changes. During the 20-years of Duntov’s chassis, Racer Kits included; the 1963 Z06, 1967-1969 L88, 1970-1972 LT-1 small-block ZR1, and the 1971 big-block ZR-2. And from 1974-1982 there was the FE7 Gymkhana Suspension for spirited street driving. On the street, Duntov’s chassis could easily handle the 327 Fuelie to the LS6 454.
In the ‘70s chassis changes were made to conform to tightening regulations. Starting in 1973 the chassis had to handle the new 5-mph crash bumpers and steel side-door guard beams. In 1975 catalytic converters helped reduce emissions, but cloaked engines. A steel underbelly had to added to the chassis as a heat shield against the very hot converters. 1980 saw a big weight reduction from 3,503-pounds to 3,336-pounds thanks to an aluminum differential, lighter roof panels, thinner material on the hood and doors, and the use of the aluminum L84 intake manifold on the standard engine. The following year, a fiberglass-composite rear leaf spring helped shed 29-pounds. Early ‘80s Corvettes don’t get much respect because their restricted engines, but their drivetrain and suspension was as good as ever. An early ‘80s Corvette with a classic SBC crate engine would make for a stout performer.
Yes, Duntov’s chassis looks crude by today’s standards. But Corvette development is always empirical. If it weren’t for the C2/C3 chassis, there never would have been a C4 chassis, and so it goes. – Scott
The long and winding road to the mid-engine C8 Corvette
Dateline 7.18.19 –The waiting is finally over! The “pie-in-the-sky” dream of Zora Arkus-Duntov of a mid-engine high-performance sports car wearing a Corvette badge has arrived. The journey to the mid-engine C8 was long, very long.
The C7 Corvette debuted on January 13, 2013 and by the end of April 2013, Chevrolet announced pricing and hard details. By the third quarter of 2013 C7 deliveries began. Then on August 14, 2014, less than a year after C7 production began, Motor Trend announced online, “SCOOP! Mid-Engine Chevrolet Corvette is a Go”.
I said, “HUH?!?!? The C7 just came out. Come on, quit it with the mid-engine tease!
That was almost five years ago and Corvette fans were tortured mercilessly with rumors, spy images, and 3D renderings. It seemed like “The Never-ending C8 Mid-Engine Corvette Story”. Oh, sure! And now, here we are. The journey to the C8 mid-engine Corvette has become epic.
Duntov passed on in 1996, so we can’t ask him exactly when did he first want a mid-engine Corvette. Duntov knew all about mid-engine sports racing cars dating back to the late 1930s. He built the mid-engine CERV-I in 1959/1960 and the mid-engine, all-wheel-drive CERV-II in 1963/1964.
There were numerous mid-engine cars built at the GM Tech Center in the 1960s that were not specifically Duntov’s cars. The first running, “Duntov” mid-engine vehicle that wore the classic Corvette cross-flags was the 1970 XP-882. This car seriously looked like a Corvette. The 1968 Astro-II looked like a Corvette, but that was R&D chief engineer Frank Winchell’s car. But Duntov got to carry the mid-engine torch.
When Duntov retired and handed over the reins to new chief Corvette engineer Dave McLellan, he told the new chief, “Dave, you must do mid-engine.” Although Duntov was a corporate anomaly during his 21-1/2 years at Chevrolet and many didn’t miss him, he definitely had the hearts of legions of Corvette fans and many GM and Chevrolet insiders.
In 1992 Corvette engineers and managers put three unique proposals on the table for consideration for the C5 Corvette. The three concepts included; the mid-engine CERV-III, a stiffer, lighter, restyled version of the C4, and the “Momentum Architecture”. The CERV-III was too expensive and no one wanted the “stiffer-lighter” concept. The Momentum Architecture design won the contest and became the C5. The C6 and C7 designes are advanced, improved designs of the basic C5 structure.
Jim Perkins was the general manager of Chevrolet in the early ’90s and out of respect for Duntov, he invited the great man to see Dave Hill’s presentation to GM leaders to review past, current, and potential future Corvette designs. Zora didn’t say much.
“Two or three days later, he called and said [imitating Duntov’s Eastern European accent], “Jim, I look at new Corvette architecture, and I am surprised. No mid-engine.” I said, “No, no mid-engine.” He asked, “Why? Why you make decision no mid-engine? You should fight for mid-engine.”
I said, “Zora, I might as well be fighting the wind. I’m not going to win that one. We’ve got the program, we’re going to go forward with it, we have a great architecture that we’re pretty well settled on.” He said, “No, Jim, you must raise issue of mid-engine.”I said, “OK, fine.”
He said, “I would like to come see you.” I said, “Well, I’m pretty busy, but my secretary will try to find a time.” I thought he was going to come in just to talk, but when he walked in that morning, he had a role of stuff under his arm. He said, “I am here to talk about mid-engine car.” I said. “OK, but I don’t know what there is to talk about.”
He rolled out these plans that he had done himself, and started talking about this mid-engine architecture. I said, “Zora, I’d like to sit here and talk with you about this, but I’m very busy, I have other things I need to do. Nothing has changed. We are not going to do a mid-engine.”
He said, “You are not going to fight for mid-engine?” I said, “No, sir. I am not. It’s a waste of time and effort. There is just no point in trying to do it. I know you’re passionate about it, and you’re probably right, but we just cannot do it.”He said, “OK.” And he rolled up his plans, put them under his arm and said, “You are not going to build mid-engine. I will raise the money, and I will build the son-of-a-bitch myself.”And he walked out of the office.”
After decades of jaw, jaw, jaw about a factory production mid-engine Corvette, it is finally here. Some time this summer the last front-engine Corvette will roll off the Bowling Green assembly line, closing the long chapter on front-engine Corvettes. Wherever Duntov’s spirit is in The Multiverse or out there in the Either, we all hope that he is happy that his production mid-engine Corvette is finally a reality. – Scott
The Corvette Chassis That Maurice Olley & Mauri Rose Built
Dateline 7.17.19, As seen in the December 2018 issue of Vette Magazine – Corvettes are kind of like a beautiful woman. Sure, she’s a beauty, but is she smart and athletic? From the beginning, Corvettes have consistently been unique, beautiful cars that look like nothing else on the road. Even the hardboiled engineer and racer Zora Arkus-Duntov was disarmed by the beauty of the 1953 Motorama Corvette, such that he immediately knew he wanted to be part of Chevrolet’s bold American sports car effort. (Zora was always a pushover for beautiful women!)
Now, it is no secret that the 1953 Corvette cars were more like “pilot program cars” or “work in progress cars.” The assembly workers and designers were literally grooming and refining Corvettes as they were being built for sale! Consequently, many of the early Corvettes from 1953 to 1955 weren’t so good.
While the initial response by the press was very positive, as cars were road tested and customers gave their feedback, the Corvette’s glow diminished. The term “parts bin car” started being bantered about. This is only partially correct and dishonors the fact that the first Corvette’s chassis was designed by one of the best chassis men of the day, Maurice Olley. Former Allison Engineering Company engineer and three-time Indy 500 winner, Mauri Rose, oversaw construction of the first Corvette chassis.
The original mission of the Corvette was to be a “sporty” street Chevy, not a racecar. The basic design and structure was so good for its day that after the bugs were worked out, and Zora Arkus-Duntov and Mauri Rose started developing racing parts for Corvette customers, a properly optioned Corvette could easily be made into a competitive SCCA racecar! In fact, with the basic design in tact and optioned with the Fuelie engine, racing suspension and brakes, Corvettes were dominating SCCA B/Production and A/Production classes by the late 1950s and early 1960s.
Three hundred Corvettes rolled off the makeshift assembly plant in Flint, Michigan between June 30, 1953 and December 24, 1953. When the St. Louis plant came online on December 28, 1953, Chevrolet produced 3,640 Blue Flame Six-powered, 1954 Corvettes – now available in four colors: Polo White, Pennant Blue, Sportsman Red, and Black. 1955 saw the introduction of the all-new, lightweight 265 Chevy engine and a 3-speed manual transmission – you’d think that sales would have seriously taken off – but they did not! Only 700 1955 Corvettes were built and only seven had the Blue Flame Six engine. What happened?
Obviously, the car stumbled off the starting line. Corvettes were expensive and the build quality was spotty at best. Even the heater and radio were optional! Keep in mind that from 1953 to 1954, there were no mainstream-manufactured American sports cars. (Ford’s Thunderbird arrived in 1955.) Sports cars were a very, very small automotive market segment. From 1953 to 1955 Chevrolet sold 4,640 Corvettes compared to 1,774,238 Bel Air cars! European sports cars were being imported to America in the early 1950s, but in very small numbers compared to the gigantic market for big American cars.
Outside of the very small world of sports car enthusiasts, the Corvette made no sense at all. The Thunderbird “made sense” because it was loaded with creature comforts and had a solid, steel body with real roll-up side windows. That’s why even though the prices of the two cars were very close, Ford sold 16,155 Thunderbirds in 1955, compared to 700 ’55 Corvettes. T-Bird sales dipped to 15,631 in 1956 and then hit 21,380 in 1957, just in time for Ford to abandon the 2-seater sports car market in favor of the four-seater personal luxury car segment.
The two biggest criticisms of the Corvette were the six-cylinder engine and automatic transmission. Lets take this apart. In-line six-cylinder or four-cylinder engines powered most European sports cars of the day, and several had exotic, double overhead-cam heads. Automatic transmissions were considered state-of-the art, advanced American automotive technology in the 1950s. Automatics freed drivers from dealing with clunky gearboxes, loose shifters, stiff clutches, and double-clutching. The automatic transmission was seen as a luxury feature.
Motor Trend Magazine’s editor (and MG owner), Walt Woron had this to say about the ’53 Corvette, “To a purist like me the idea of an automatic transmission in a sports car is unthinkable, even if the lever is next to the drive shaft tunnel.” But after three-time Indy 500 winner Mauri Rose gave Mr. Woron a ride around the GM test track, easily downshifting, braking, and accelerating out of corners, Woron said, “I had to admit grudgingly that an automatic could be at home in a sports car.” It is ironic that today the C7 automatic Corvette delivers performance on par with the manual transmission C7. It seems that we have come full-circle.
But the unkindest insult leveled against the C1 Corvette was that it was a clumsy attempt by Chevrolet to build a “parts bin sports car.” As if to say that Harley Earl, Ed Cole, Maurice Olley, and Mauri Rose slap-dashed together car and presented it as “America’s sports car.” I will dispel this myth once and for all. Although it was Harley Earl that came up with the concept and directed the shape of the first Corvette, it was Chevrolet’s new chief of engineering and soon to become general manager, Ed Cole that was the corporate driving force behind the project. Cole was part of the generation of WW-II era men with a “Let’s get it done, now!” attitude. Cole loved being a corporate rebel. His motto was, “Kick the hell out of the status quo!” Cole liked to “shake things up” so he created his Dream Team to create his Chevrolet sports car.
Maurice Olley was in the closing years of his long career as an engineer and was recognized as one of the best suspension and R&D engineers of his time. Olley was British had been the personal designer for Sir Henry Royce (as in, “Rolls Royce”) and was later the chief engineer for Rolls Royce in America. From 1930 to 1937 Olley was a special projects engineer for Cadillac and General Motors. During WW II Olley was the engineering representative for Rolls Royce LTD, USA (aircraft engines) and then was appointed to the British Ministry of Supply (tanks). Cole hired Olley in 1952 and knew he had the best chassis engineer he could find. Olley had over 40 U.S. and Canadian Patients to his name, authored numerous technical papers, and wrote the book, “Chassis Design: Principles and Analysis”. (This book is available on Amazon.com)
Mauri Rose was an engineer first and a racecar driver second – but his driving was a mighty fine “second”! Rose was the third driver to win the Indy 500 three times – 1941, 1947 and 1948. The first was Louis Meyer 1928, 1933, and 1936. The second was Wilber Shaw in 1937, 1939, and 1940. Rose was also one of the test drivers for GM’s 1953 Firebird XP-21 gas-turbine experimental car. Mauri drove the experimental car at (where else?) the Indianapolis Speedway – just for “feasibility testing.” Fourteen years later in 1967, Parnelli Jones almost won the Indy 500 with the STP-Paxton Turbine-Engine racecar.
When Ed Cole hired Rose, he told him, “You’re the man to do the sports car!” The rest of the main players on the dream team roster included stylist Robert McLean and body engineer Ellis “Jim” Premo. McLean was tasked with establishing the basic parameters for Earl’s Project Opel sports car. He set the wheelbase at 102-inches and placed the in-line-six engine back seven-inches closer to the dash than in a regular Chevy. Weight distribution came in at 53/47 front-to-rear. Earl wanted trendy wrap-around windshield glass and clear plexi headlight covers.
In April 1952, using a full-size model, Ed Cole and Thomas Keating pitched the concept of an “American sports car” to GM president Harlow Curtice. They were seeking approval to build an experimental version to showcase at the 1953 Motorama show. Curtice liked what he saw and approved the project. With an approval in hand, Cole showed Maurice Olley the full-size model and tasked him with designing a suitable chassis. The task was to: “produce a sports car, using existing, reliable components, adequate performance, comfortable ride, stable handling, in less than seven months to the Motorama Show and 12 months to production.” Ten days later, Olley had the basic chassis design sketched out for “Project Opel.” The name “Corvette” would arrive in September 1952, thanks to the work of Chevrolet PR man, Myron Scott.
Here are the basics of Olley’s “Project Opel” chassis. The box side rails were made from two U-channels per side, nested together in opposite directions to form a box-section, then stitched-welded together, and shaped. The center X-member was made from I-beam steel with holes cut in the “I” part of the beam for the duel exhaust to pass through. There were 11 body mount points on the chassis. The completed frame weighed 213-pounds – considered “light” in 1952!
R&D engineer, Walter “Walt” Zetye worked out the final details of the suspension and steering systems. The independent front suspension, while looking quite ordinary, had just been totally redesigned in 1949 by GM engineer Kai Hansen. Maurice Olley had also done independent front suspension R&D work for GM in the 1930s while running the Product Study Department. For its day this was considered a major improvement over I-beam front axles. The one-inch diameter Delco shocks were mounted inside each coil spring, between parallel-wishbone A-arms, with kingpin spindles and ball joints. The oversized front sway bar was mounted high atop the front engine cradle/crossmember that was bolted to the right and left side rails.
The rear suspension used a stock Chevy differential with 3.55:1 gears and 51-inch long Chevy leaf springs, commonly known then as a “Hotchkiss drive system.” The Hotchkiss system used a driveshaft with universal joints at both ends. Most Detroit cars used a torque tube that only had one U-joint behind the transmission. Because the centerline of the crankshaft/transmission driveline was above the X-member of the frame, U-joints were needed at both ends of the 36-inch driveshaft because the rear axle input was lower than the engine/transmission centerline. The rear axle sat atop four leaf springs and was held in place with U-bolts. The leaf spring shackles held the rear axle in position for-and-aft. Rebound straps limited rear axle rebound. (In 1959 radius rods connected both sides of the rear axle to the frame rails to cure wheel-hop.) A Saginaw worm-and-sector steering box was used with a mildly-quick 16:1 steering ratio. Remember, this was the days of no power steering, so steering ratios were high and steering wheel diameters were large for increased mechanical leverage to make steering easy. Brakes were to be the bane of Corvette racers for years, but for street use, stock Chevy brakes with 11-inch drums were used on all four wheels and were considered adequate.
The Blue Flame Six engine is much maligned, but for its day, was pretty stout and had many improvements over the old 235-CID, 115-hp Stovebolt Six. Inside, the Blue Flame Six had aluminum pistons (a first for this engine), improved lubrication, and more durable main bearings. Compression was bumped up to 8:1 and a more aggressive solid-lifter cam was used with .405-inch intake lift and .414 exhaust lift. A metal cam gear replaced the standard fiber cam gear, dual valve springs and stronger exhaust completed the valvetrain. A high-efficiency water pump was installed and shielding was added to the distributor and plug wires. To eliminate the need for a hood bulge, three horizontal Carter one-barrel carbs were used and mounted to a special aluminum intake manifold. The exhaust system used a split manifold with dual exhaust pipes and mufflers. A high-efficiency water pump with a remote header tank for the radiator kept the hot-rodded Blue Flame Six in the cool zone. While the final version of the Blue Flame Six was rated at 150-horsepower, Mauri Rose said, “We finally got 190-horsepower… but the idle isn’t so good and it didn’t start so well… so we gave up on the roller-camshaft. We ended up with around 150-160-horsepower.”
Mauri Rose literally hand-fabricated the very first Corvette chassis as if he was constructing a purpose-built racecar. Rose later said, “We did all the work in a loft, not the Chevrolet factory. We built the whole chassis there. This was a crash program. They took their sketches right to the build shop and roughed up the chassis in wood and Styrofoam right off the drawing boards. If it wasn’t right, they tore it down and started over.”
The use of the 2-speed Powerglide automatic transmission was purely for expediency. It was the least costly way to build the car on such a short notice. The three-speed manual transmission arrived in late 1955 and the four-speed in 1957. Most Americans considered the automatic transmission an automotive advancement, but to traditional sports car buffs, this was sacrilege. Performance of the 1953 Corvette was considered “good” for its day: 0-60 time was 11.5-seconds, the quarter-mile in 18-seconds, and the top speed was 110-mph.
Here’s how Maurice Olley defended the Corvette’s automatic transmission,“As the sports car appeals to a wider and wider section of the public, the center of gravity is shifting from the austerity of the pioneer towards the luxury of modern ideas. There’s no reason to apologize for the performance of this car with its automatic transmission.” Clearly, Olley wasn’t into racing, but then again, in 1952 when the Corvette chassis was being designed, here was Chevrolet’s official statement for their new two-seater sports car; “The car is not intended to be used as a racing car.”(By 1956 this was not the case.)
While the first three years of the Corvette were rough, the basic structure design was unchanged from 1953 to 1962. The makeover of the 1956 model was a game-changer, even though the basic structure and interior were the same. The public was used to seeing new designs on familiar cars, so a refresh wasn’t that unusual. The new design was still looked clean and light. Because Duntov went on to become the Corvette chief engineer, Zora is generally credited with the long series of performance parts, unofficially known as “racer kits.” However, there’s more to that story.
Rose and Duntov’s experience and expertise was so valued that in September 1955 Ed Cole decided that starting with the 1956 Corvette, the two men would be responsible for the design and development of RPO equipment necessary to make the Corvette capable of competing in racing events. By January 1956, “racer kit” options started to become available. This was the beginning of Chevrolet’s first venture into the world of factory-backed sports car racing, as plans were laid out for a racing team to field modified Corvettes to race at Sebring and Le Mans.
Initially, Duntov was not excited about the plan because of the1955 Le Mans disaster that killed 83 spectators, one driver, and injured over 120 others just a few months before. Zora knew the Corvette’s brakes weren’t up to racing standards and did not want to see a Corvette cause a similar disaster at Sebring. This was no doubt the impetus for the elaborate brakes that were part of the 1957 RPO 684 Heavy Duty Racing Suspension option.
Early in 1956, Chevrolet’s Marketing Department encouraged Corvette customers to race their Vettes with an ad headline that read, “Bring on the hay bales!” After the Corvette’s big class-win at Sebring in the March 1956, Chevrolet ran an ad featuring the Corvette Sebring racer with the headline, “The Real McCoy”. Chevy’s new general manager, Ed Cole announced, “We’re in the sports car business to stay.”
The magic that Duntov and Rose delivered via their RPO program was pure, racing parts development. Duntov and his engineers improved shocks, shock mount points, springs, sway-bars, brakes, rear suspension, added rear trailing arms, and many other small details. This added up to a car that was a solid foundation for a serious SCCA B/Production and A/Production racecar. Rose got the prototype parts to the racers and even thrashed a few Corvette racecars with Smokey Yunick. Rose’s strong, “Let’s get to work and get dirty!” work ethic impressed Yunick, a man NOT easily impressed! Smokey said about Rose, “He was a hard-working, sharp, ‘run to win or bust’ sort of cat.”
Maurice Olley retired on December 31, 1955 and was inducted into the National Corvette Museum Hall of Fame in 2008. Mauri Rose went on to drive the 1967 Camaro Pace Car at the 1967 Indy 500 race, after which he faded into automotive history, and died on January 1, 1981 at the age of 74.
So, when you see stories about championship C1 Corvette racecars, remember that the commonality they all share is that they ride on the chassis that Olley and Rose built. – Scott
Stingray Chevrolet, in Plant City, Florida, hosts the celebration of 40 years of Bill Tower’s ownership of Grand Sport #005
Dateline: 12.4.18 – Photos by K. Scott Teeters – Milestone dates only happen once. In September 2018 I was talking with former Corvette development engineers Bill Tower and said to him, “Bill, do you realize that this December it will be 40 years since you bought your Grand Sport?” Bill sputtered a little and said, “Oh man, now you’re really making me feel old!” I said, “Ain’t we all, Bill!” and we both had a good laugh. Then I said, “You should have a party, or something, Bill.”
Bill thought about it and contacted his friend, Steve Hurley, owner of Stingray Chevrolet (a GREAT name for a Chevy dealership!), and Steve said, “Let’s do it here at the dealership. The 25-foot Christmas tree will be up and we’ll make it great!”
On December 2, 2018 Stingray Chevrolet was all Corvettes to commemorate Bill Tower’s 40th anniversary of ownership of Grand Sport #005, the winning-est of all five 1963 Grand Sport (aka, “The Lightweights”) Corvettes. When word got out, Corvette fans from far and wide said, “We’ll be there!”
The notable guests included retired Sr. VP of Global Design, Ed Welburn, curator from the National Corvette Museum Derek Moore, Grand Sport Registry owners John and Patty Hutchinson, CorvetteBlogger.com editor and owner Keith Cornett, Hendrick Performance infrastructure Manager and lead photographer Larrie Matthews, and nearly 150 Corvette fans.
Ed Welburn talked about his love affair with grand Sport #005 and how a pen & ink illustration of the car helped get him into GMI (General Motors Institute) to become a car designer. Then Stingray Chevrolet owner Steve Hurley interviewed Bill Tower about why the Grand Sport was such an important part of the long tern success of the Corvette. A Q&A session from the audience rounded out the celebration.
I will be authoring an in-depth article about the even for the 2019 February issue of Vette Vues that will be out in early January 2019.
Bill Tower is all-in when it comes to the history of the Corvette and how racing made the car what it is today; a world-class all-American sports car. In the last 20 years the Corvette Racing Team has had 13 championships, including the last three years in a row! (2016, 2017 & 2018) This would not have been possible were it not for the early efforts of Zora Arkus-Duntov and many others, that made sure that Corvette racers had the hardware to be successful against anything the international community of sports racing car had.
Stingray Chevrolet looked stunning! Steve Hurley and his team did a delightful job of decorating the showroom with a spectacular 25-foot tall Christmas tree, decked out with red and gold trim. The showroom was wall-to-wall Corvettes, including production Grand Sports, a 2013 60th Anniversary Corvette, classic Corvettes from the 1950s, 1960s, and 1970s, plus two late model COPY drag racing Camaros. In front of the dealership C7 ZR1s, Z06’s, and Grand Sports stood guard. And by the time the event started at 2pm, the parking area in front of Stingray Chevrolet was filled with Corvettes from the Registry of Grand Sport contingent, as well as friends and fans.
Rain had been forecast but never happened; it was a beautiful Florida day for a Corvette event. And the Corvette eye candy was extraordinary. Special thanks to Steve and Susan Hurley, owners of Stingray Chevrolet for hosting the event, the Stingray Chevrolet team for their assistance with setup on a Sunday, Doug White for his support and setting up the continuous video presentation, and Derrick Moore from the National Corvette Museum for video recording the event. And lastly, Bill and Betty Tower for having the foresight 40 years ago to go out on a limb and buy Grand Sport #005 when they could.
On behalf of the Corvette community, thank you to everyone that made this event happen! – Scott
PS – Bill Tower actually purchased Grand Sport #005 on December 24, 1978 from Dave Erwin in Painted Post, New York.
The C8 Mid-Engine Corvette will be an awesome machine, but does this “look” like a “Corvette”? What would Bill Mitchell think?
Dateline: 11.16.18 – Main Photo Credit: www.Motor1.com, except where noted, Image Credit: GM Archives –As reported on November 8, 2018 by Motor1.com, rumor clouds are gathering and indicating that the C8 mid-engine Corvette will debut at the NAIAS Show in Detroit in January 2019. That seems likely since the C8 did not debut at the Dubai International Motor Show.
A mid-engine Corvette has been the ultimate pie-in-the-sky Vette since the 1960s when mid-engine was the best layout for balance and the state-of-the-art of tires back in the day. A mid-engine Corvette was Zora Arkus-Duntov’sultimate dream Corvette. There’s a good chance that the C8 will be called “Zora”.
But we’ve come a long way, baby, since the days of 100-percent mechanical supercars. Between electronics, computers, vastly superior materials, and tires with more sticky than rubber cement; does the mid-engine layout still make sense?
I would submit that the success of the C7.R argues the case that a mid-engine layout is no longer needed. The Corvette Racing Team won the 2018 Championship without scoring a single class win. It’s all about consistency and the points race. Then, factor in the disadvantage put upon the C7.R Corvettes, thanks to IMSA’s BoP rules, and clearly, the front mid-engine C7.R Corvette was the superior car in the series.
Over the past sixty-five years the Corvette has had many contenders, has vanquished them all, and is truly a world-class champion race car and “America’s Sports Car” This begs the question; is a mid-engine Corvette relevant in today’s world of electro-mechanical performance cars?
The Corvette mystique has many factors; performance, affordability, durability, utility, unique good looks, history, and more. For the most part, a Corvette is a car that you can live with as a daily driver, especially since the arrival of the 1984 C4 with its functional hatchback roof. You can do light grocery shopping, go golfing, and take a trip with a Corvette, thanks to the generous amount of storage area in the back (as sports cars go).
This kind of utility will not be part of the mid-engine Corvette. This is a packaging issue and is common with all mid-engine sports cars. Remember the Pontiac Fiero? That was a very cool, affordable mid-engine sports car, but all you could store in the “trunk” in the back was two slim brief cases.
Probably a year from now we will be seeing lots of C8 mid-engine Corvettes on the road. But this will not be a GT (Grand Touring) car. No one will be taking long trips in a C8, unless they have a support car following along with their gear. And I doubt that any C8 owner will be attaching a tow hitch for a motorcycle trailer, either.And lastly I want to address the C8’s looks. I have had a love affair with Corvettes since 1965 when I didn’t even know what I was looking at, other than it was the most beautiful car I’d ever seen in my young life. I am probably committing sacrilege, but I have to be honest. While subtle surface details are nearly impossible to make out on the camoed C8 mule cars, the overall shape and proportion of the C8 is obvious. Twenty years ago, we depended on gifted automotive artists, such as Mark Stehrenberger, to provide magazines with renderings of upcoming Corvettes in the months before official debuts. But today there are numerous very talented digital artists that create “renderings” that can pass as actual photographs. Okay, so here the “sacrilege” part.
I am not liking what I’m seeing. To my artist’s eye, the car looks stubby and bulky; a collection of add-on design elements. The styling appears to be engineering-driven. A beautiful car should hit you immediately. You shouldn’t have to think about it; there should be an immediate, visceral response; a “WOW!”
In October when Motor1.com showed the upcoming McLaren Speedtail, it got a “WOW! WOW! WOW!” from me. I mentioned to Marty Schorr from CarGuyChronicles.com and founder of Vette Magazine, that if the Speedtail body was the C8 Corvette, I’m be a “Happy Corvetter”! Marty concurred.
The C5 Corvette was almost a mid-engine car. The 1990 CERV III was a serious contender for the C5 but was deemed too expensive. The CERV III was a “WOW!” Corvette for me. Prior mid-engine prototypes were almost all gorgeous cars that screamed “CORVETTE!!!” That’s why I have added images of past mid-engine Corvettes in this post. I can not imagine that VP of GM Styling Bill Mitchell would be happy with the C8. Zora would be THRILLED! But then again, Duntov and Mitchell often and famously butted horns.
Believe me, my highest hope at this point is that I’m dead wrong. We’ll see soon. – Scott
Watch some old school fun in this ride-along video from the passenger-side seat of this racing 1956/1957 Corvette.
Dateline: 11.13.18 – Corvette racecars from the 1950s look absolutely prehistoric from our modern perspective. They were 100-percent mechanical beasts. This video beautifully captures the sights and sounds of this old world racing Corvette.
Back in the day, just like today, Corvettes had plenty of grunt and only needed improved suspension and brakes. That’s what Chevy’s RPO racing parts program was all about. Chevrolet general manager, Ed Cole, charged engineers Zora Arkus-Duntov and three-time Indy 500 winner Mauri Rose, with running the program.
Duntov oversaw the engineering in Detroit and tested the special parts at the GM Proving Ground, and Rose was the field engineer that worked with Smokey Yunick and various racers to field test and improve the parts. By the end of the 1959s, Corvettes were winning championships and were beginning to dominate.
Just for some contrast, I’ve included an in-car video from one of the C7.R Corvettes. Here’s Tommy Milner in the C7.R at Daytona in 2014.