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.
Corvette chief engineer Tadge Juechter delivered the C7 Corvette, the C7 Z06, the C7 Grand Sport, the C7 ZR1, and soon the 2020 mid-engine C8 Corvette.
Dateline 1.29.21, Images: Graphics by the Author, Image from GM Archives – All five Corvette chief engineers contributed mightily and in their own unique ways. But only Tadge Juechter has the distinction of having done hard engineering on five generations of Corvettes. When Juechter went to work in 1993 as chief engineer Dave Hill’s right-hand-man, there were two objectives; keep the then-current C4 fresh and interesting; and design and develop the most revolutionary Corvette to that date, the C5. After Hill’s retirement, Tom Wallace was Vehicle Line Engineer (VLE) and chief engineer for the Corvette. Wallace accessed that because of Juechter’s 15 years of experience, he was the right man for the chief engineer position. Wallace stayed on as VLE and eventually took an early retirement offer.
While Juechter didn’t have the racing background that Hill and Wallace had, he was raised in a Porsche household and liked to tinker around with mechanical things. As a young teenager growing up in Chappaqua, New York in the ‘70s, Juechter built a prehistoric mountain bike with a full front and rear suspension. His folks even gave him their wrecked Cadillac to take apart.
During Juechter’s college years at Stanford, he worked two summers on a GM assembly line, an experience not to his liking. Juechter graduated with degrees in aerospace and mechanical engineering and had no intention of working for GM. Then in 1978 a friend asked Juechter to tag along to a GM interview and ended up interviewing as well; and was offered a job. The late ‘70s and ’80 was a challenging time for the American car industry, but at least Juechter had a solid job. In the car business, if your ambition is upper management, an MBA is a must-have degree. Juechter earned his MBA from Stanford GSB in 1986.
By the time Juechter interviewed with Hill for the position of Assistant Chief Engineer, he was aware of the aging Corvette and impressed with the in-the-works C5. The C4’s plastic interior was a major bone of contention with Juechter. Hill was impressed and Juechter got the job. The jump from the early ‘80s designed C4 to the C5 was revolutionary. The creation of the Corvette Racing Team was the beginning of the deliberate merger of Chevrolet engineering and Corvette racecar engineering that was poured into the C5 Z06. Early on, Chevrolet general manager Jim Perkins wanted an inexpensive Corvette that would appeal to racers; this became the ’99 Hardtop and the Hardtop became the C5 Z06. While the C6 was an evolved version of the C5, no one was expecting the 505-horsepower 427 Z06 with an aluminum frame and dry-sump oil system.
From 2005 to 2008 sales averaged 36,816 cars per year. In 2006 Tom Wallace was Corvette VLE and chief engineer. While Wallace was a racer, his Corvette experience was a little thin. When Wallace learned that Juechter and his team were working on a mid-engine prototype, he knew that Juechter was the brains behind the Corvette. Juechter was promoted to chief engineer, North American Corvette.
Juechter has said that he was shocked when given orders to make the C6 ZR1; the goal was to build the best possible Corvette for $100,000. A big-block was briefly considered but rejected because of its weight. All-Wheel-Drive was not possible on the C6’s platform. The Z06 was to be the track car and the ZR1 would be GM’s halo, Grand Touring supercar.
Then the economy stalled out and the in-the-works C7 was put on hold indefinitely. Wallace took GM’s early retirement offer, leaving the Corvette all to Juechter. When GM slammed into bankruptcy in June 2009, for a time it looked like it was curtains for GM. But it turned out that the government auditor that was looking into the Corvette was a car enthusiast and knew about the pending C7. Upon examining the books, it was discovered that the Corvette was one the few GM car lines that was making money. Juechter’s team was told to get busy on the C7. The Corvette and the Bowling Green assembly plant were spared.
By the time you read this, the C8 will have made its debut and will be the most revolutionary Corvette ever. Previously, the C5 had that honor because of its all-new engine and drivetrain, and its hydroformed perimeter frame and backbone center section. The C6 and C7 generations are both evolutionary versions of the C5. The C5 and C6 are Hill’s Corvettes; the C7 and C8 are Juechter’s Corvettes. As of this writing, we know the basics of the C8, but none of the hard details. So lets look a Juechter’s C7.
A big part of Juechter’s job as VLE is to make sure there’s a Corvette for everyone with a variety of price points, and a base car that offers outstanding visual and performance value. Juechter said, “It helps having worked on the C5 and C6 because you know where a lot of the land mines are.” With horsepower ever increasing, it’s critical that the car be made easier to drive. The base C7 has 455-net horsepower; way more than any big-block ever had; yet the C7 is a car that is easy to live with. The 755-horsepower 2019 ZR1 is absolutely astonishing; it can perform on par with exotic sports cars, yet be a comfortable, usable GT machine. Electronic suspension, steering, braking, rev-matching, paddle-shift 8-speed automatic and fuel management are responsible for a balance of extreme power and civility. Imagine trying to drive a Greenwood widebody racer on the street.
When the C7 was unveiled, fans were stunned to learn that the base model had an aluminum frame and that later the Z06 and ZR1 would be available as a coupe or convertible and with an 8-speed manual or automatic transmission. Another first was achieved; the 8-speed automatic was quicker than the manual version.
Corvette interiors have often been a bone of contention with critics and the C6 took big hits for its interior. To get C7’s interior spot-on, Juechter made sure designers had set-of-the-pants experiences of life inside a 1-G cockpit; to know what it feels like having skin pressing on hard objects. He also made surer there were no distracting infotainment systems; just important information for spirited driving. The C7 has received rave reviews for its interior.
Concerning the C7 ZR1, initially there were no plans to make the car, as designers didn’t think they could do more beyond the Z06. But after a few years, plus aero input from the Corvette racing team, a new plan emerged to make the ZR1 the most powerful, stable, advanced front-engine Corvette ever offered. Many speculated that Chevrolet might build the front engine and mid-engine Corvettes side-by-side, but that will not be the case. C7 production will end in summer 2019 and the last C7 will be a black Z06 that will be auctioned off, with proceeds going to the Steven Siller Tunnel to Towers Foundation.
While Juechter was an integral part of the C5 and C6, those were Hill’s Corvettes. Even though Juechter guided the C7, the C5, C6, and C7 all have Hill’s Corvette DNA. The C8, on the other hand, is Juechter’s Corvette. People expect more of everything today, and everything is riding on the mid-engine C8. – Scott
This concludes my Corvette Chiefs Series. Below are links to parts 1-to-4. Enjoy
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.
Photo Credit: www.CorvetteBlogger.com
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
Dateline: 8-11-20– This story was originally published in the now-defunct Vette magazine, August 2019 issue. Story, Illustrations & Graphics by K. Scott Teeters) On November 18, 1992 when it was announced that Cadillac Engineering Program Manager David C. “Dave” Hill would become the new Corvette Chief of Engineering, the Corvette community asked, “Why is a Cadillac man taking over the Corvette and what can he bring to the brand?” Hill was the right man for the job, at the right time, and he brought a lot!
In the early ‘90s GM was in financial trouble. The company had lost its way in the ‘80s and in 1989 when Jim Perkins came back from Toyota to become the general manager for Chevrolet, he said he didn’t recognize the place. Moral was low and infighting was rampant. To stop the financial hemorrhaging, every car line was being looked at, and once again, Corvette was on the chopping block.
Thanks to Dave McLellan, the C5 was in the planning stage but only “on paper”. Perkins was Corvette’s “corporate angel”. He argued with GM brass that “Corvette” was one of the best-known automotive names in the world. He told them, “… if you don’t have enough confidence to trust my judgment that we can make money on this car, then I shouldn’t be here.” Perkins won the argument, but with McLellan ready to take early retirement, he needed a new Corvette chief with the know-how for profitability, performance, and quality.
Hill graduated in 1965 from Michigan Technology University with a degree in engineering and went right to work for Cadillac in their engine power development lab. From there, Hill worked his way through many departments. In 1970 he earned his Masters Degree in Engineering from the University of Michigan. Through the ‘70s and ‘80s at Cadillac, Hill was a Senior Project Engineer; Staff Project Engineer; Body and Chassis General Supervisor; Development, Emissions, and Transmission Staff Engineer; and Chief Engineer for the Allante, DeVille, and Concours models. In May 1992 Hill was promoted to Engineering Program Manager for Cadillac. Hill was deeply versed in GM’s premiere car line.
During Hill’s tenure, Cadillacs weren’t the performance cars they are today, but don’t conclude that Hill was into cushy Caddys; he was into sports cars and racing. Hill owned a 1948 MGTB, a 1970 350/350 Corvette Coupe, and from 1968 to 1972 he raced a Lotus Super 7 in SCCA competition.
Like McLellan, Hill had two objectives; first, keep the C4 fresh, and second, design and develop a totally new Corvette. Sales for 1991-to-1996 Corvettes averaged around 20,000 units; a big drop from 1984 when 51,547 Corvettes were sold. Everyone knew the C4 needed to be replaced. From ’93 to ’96 Hill and his team made small improvements and special editions to keep things interesting. In 1993 the 40th Anniversary Package was offered. The ’93 ZR-1 got a power boost from 375-to-405-horsepower. In 1995 the Indy 500 Pace Car Replica, was limited to 527 units. The 1996 lineup had two special editions; the Collector Edition (5,412 units built) and the Grand Sport (1,000 units built; 810 coupes and 190 convertibles).
The transition from the C4 to the C5 Corvette was the most radical of all generational transitions. Typically, when we think “radical,” we think “mid-engine”, “double-overhead-cam” or “turbocharging”. The C5 wasn’t any of that; it was better. In one fell swoop, the basic Corvette had the following; a hydro-formed perimeter frame with a wishbone backbone center spine, an all-new all-aluminum fuel-injected engine (the LS1), connecting the engine and new transaxle was a torque tube; the suspension and brakes were mostly aluminum, slim and lightweight; and an all-new slippery body and lush interior. The entire structure of the car was locked in together with each component designed as a stress-member and was designed to be a convertible. The design was so efficient it had over 1200 fewer parts. This was a Corvette like no previous model had ever been. It was the most radical Corvette to date and the basic structure concept is still used in the C7. The mid-engine C8 will be here soon and if Chevrolet decides to offer front and rear-engine configurations, a C9 will likely use the C5/C6/C7 concept, possibly in carbon fiber.
Sales of the 1997 Corvette didn’t look good, coming in at 9,752. It wasn’t that buyers didn’t like the new car, Corvette plant manager Wil Cooksey made sure that as cars were being built, all problems and process issues were solved and implemented. In 1998 the convertible was released and sales hit 31,084; the best since 1987. C5 sales never went below 30,000 and the best year was 2002 with 35,767; the best year since 1986. Customers were very happy with their C5s with its vastly improved structure that allowed the suspension to be calibrated like never before.
When the C5 was still on the drawing board, a “Billy Bob” strippo model was considered but not explored. Not long after the C5 was released, that concept was flushed out and the result was the ’99 Hardtop model. There wasn’t much of a savings as the Hardtop was only $394 less than the coupe. Sales only hit 4,031 in ’99 and 2,090 in ’00. But engineers learned something interesting. By bolting on and bonding the hardtop, the overall structure was 12-percent stiffer. This was that “something extra” that a performance model could use. The C5 Z06 was genius. With the more powerful 385-horsepower LS6, upgraded brakes, suspension, wheels and tires, a new Corvette legend was forged.
Hill had another ace up his sleeve that brought racing glory to Corvette and impacted the C6. In the fall of 1998, a factory-backed racing team was approved and the cars were christened, “C5-R”. Racecar builders Pratt & Miller were contracted to build the race cars. Hill used Pratt & Miller as his defacto racing engineering team. The Corvette Racing Team became world-class champions, won 1st and 2nd at Le Mans in 2001, 2002, and 2004, as well as every race in 2004!
By 1999 Hill’s engineers informed him that they had done everything they could with the C5 platform. To take the car to the next level, they would have to start the C6. While the C5 and C6 structure is similar, the C6 is all-new; with no important carryover parts. But what no one was expecting was that the Z06 would get a 100-horsepower bump, plus have an aluminum frame. No one was asking for this, but that’s what they got. The C6 Z06 was the most brutish Corvette ever offered.
Hill once said, “My favorite Corvette is the next one.” Mr. Cadillac insisted on three key things; state of the art performance and technology; passionate design; and tremendous value. In an interview with c6registry.com, Hill said, “Being involved with Corvette brings out the best in all of us who have the privilege of working on it. It represents the best that GM has to offer; along with the best America has to offer. The Corvette is very personal. We’re not talking about transportation here; we’re talking about a product that changes someone’s lifestyle, and that causes us to be enthusiastic about our duty.” Hill retired on January 1, 2006, and was inducted into the National Corvette Museum’s Hall of Fame in 2006. – Scott
PS – Be sure to catch all 5 parts of my Corvette Chiefs Series
Dave McLellan, Heir to Duntov’s Engineering Throne
(Dateline: 7-3-20 – This story was originally published in the now-defunct Vette magazine, July 2019 issue. Story, Illustrations & Graphics by K. Scott Teeters) – When Dave McLellan took over as Corvette’s new chief engineer on January 1, 1975, it was a whole new world. The prevailing trends went from performance cars to safer cars with reduced emissions. Not even Duntov could have made a difference in the ‘70s. But as performance went down, Corvette sales went way up! The sales department was happy, but the Corvette was really getting old. Dave McLellan was an unknown to the Corvette community and many wondered what he would bring to the brand. It turned out; he brought a lot!
McLellan was a car guy. He rebuilt his family’s Frazer and entered the Fisher Body Craftsmen’s Guild Model Contest. Upon graduation from Wayne State University in Detroit with a degree in mechanical engineering, GM hired Hill on July 1, 1959. Thought the ‘60s Hill worked at the Milford Proving Ground on noise and acoustics issues with GM tank treads, Buick brakes, and tuned resonators for mufflers. Hill was also going to night school to get his Master’s Degree in engineering mechanics. In 1967 Hill was part of the group that planned and operated the 67-acre Black Lake where ride, handling, and crashworthiness tests are performed.
Chevrolet engineering brought in Hill to work on the 1970-1/2 Camaro and Z28. Hill wanted to move into management so he took a yearlong sabbatical and attended MIT Alfred. P. Sloan School of Management. The school emphasizes innovation in practice and research. In July 1974 Hill was Zora Arkus-Duntov’s part-time assistant, training for taking over the position in 1975.
While Hill didn’t have Duntov’s racing experience, he owned several Porsches and understood racing sports cars. As Duntov was leaving, he told Hill, “Dave, you must do mid-engine Corvette.” Little did they know that it would finally happen forty-five years later.
When Duntov took control of Corvette engineering in 1956, he had to boost sales and make the Corvette a performance car and a capable racecar. When Hill took control, Corvettes were never selling better, but the platform design was nearly fifteen-years-old. Hill had to keep the car fresh, hit the new requirements, and maintain performance; all with a limited budget.
Management figured that the Corvette had a captive audience, so they didn’t have to spend money to change anything. Fortunately, that lame notion was overruled. The 1978 glass fastback and the 1980 front and rear bumper covers were excellent updates. Another major issue was quality control. The St. Louis assembly plant made three other cars and often workers were unfamiliar with the specialties of the Corvette. This issue didn’t get fixed until the plant was moved to the Corvette-only Bowling Green facility.
McLellan knew that the C3 needed to be replaced, as the chassis was designed around 1960! For a brief period, it looked like the mid-engine Aerovette would become the C4, but Chevrolet decided to abandon all mid-engine programs. The all-new C4 began to take shape in Jerry Palmer’s Chevrolet Studio Three in 1978. When the C4 debuted in December 1982, it received rave reviews, despite the fact that suspension engineers later admitted that they over-did-it with the stiff suspension. By 1985 the suspension was softened and the 150-mph Corvette won Car and Driver’s “Fastest Car in America” award and began the total domination of Corvettes in the SCCA Escort Showroom Stock racing series from 1985-to-1987. Porsche bought a Corvette to take apart to find why the car was unbeatable. By the end of 1987, SCCA kicked out all of the Corvettes for being too fast! McLellan followed up with the Corvette Challenge factory-build racecars.
McLellan’s personal style was more suited to the intricacies of modern electronic computer-controlled performance cars than Duntov’s. Where Duntov’s enthusiasm was effervescent, McLellan was laid-back, approachable, but not shy with the automotive press. After the successful rollout of the C4, McLellan took on four very serious performance projects for the Corvette; The Callaway Twin Turbo option, the ZR-1 performance model, the LT-5 Lotus/Mercury Marine performance engine, and the mid-engine CERV-III. Let’s look at all four projects.
“Supercars” were the rage and by 1985 Porsche had their 959 and Ferrari was about to unleash their F40. To have something to offer while McLellan was starting his ZR-1 project, a deal was made with Reeves Callaway to build brand-new Corvettes with a Callaway Twin Turbo package. The cars had 345-horsepower (stock Corvettes had 240) and from 1987-to-1991 RPO B2K was the only non-installed official RPO Corvette option ever offered.
The ZR-1 super-Vette had two components. The first was its Lotus-engineered, all-aluminum, double-overhead-cam engine built by Mercury Marine. McLellan’s engineers set down the size parameters and horsepower objective; Lotus did the rest. McLellan turned to the best manufacturer of all-aluminum, performance marine engines in the country, Mercury marine. The end result was the beautiful jewel-like LT-5, an engine that is still respected today. The second component was the widening of the ZR-1’s body to cover the enormous P315/35ZR17 rear tires and beef up the car’s drivetrain and suspension.
The 1990 CERV-III Corvette was McLellan’s vision of Duntov’s mid-engine Corvette, with electronic steroids. The car had a carbon fiber Lotus-style backbone chassis, four-wheel steering, active suspension, a transverse, 650-horsepower twin-turbocharged LT-5 ZR-1 engine and a dry-sump oil system, and a four-speed transaxle. This was the final design that started out as the Indy Corvette in 1986 and had a top speed of 225-mph. And lastly, the CERV-III was designed to be manufactured.
Photo: GM Archives
When McLellan was part of the 1992 “Decision Makers” three-man internal Chevrolet design group, gathered to evaluate the direction of the C5, McLellan chose the CERV-III concept over the front-engine “Momentum Architecture” and the stiffer/lighter restyled C4. But the CERV-III was deemed too expensive for the market. The “Momentum Architecture” with its backbone structure, a transaxle, and an all-aluminum engine with design elements from the LT-5, lives on today in the C7.
McLellan oversaw the three-year, 1990-to-1992 mid-cycle refresh. The process started in 1990 with an all-new dash; 1991 saw new front and rear bumper covers; and in 1992 the 245-horsepower L98 was replaced with the 300-horsepower LT1.
In 1990 McLellan won the Society of Automotive Engineers’ Edward N. Cole Award for Automotive Engineering Innovation. In 1991 GM was offering early retirement packages, allowing 53-year old employees to receive the same benefits as those retiring at 62. McLellan took the offer and stayed on as a consultant while GM looked for a suitable replacement. McLellan was fortunate enough to be in his consulting position on July 2, 1992, when he was on hand to see the one-millionth Corvette roll off the Bowling Green assembly line. What a thrill for a car that McLellan had given so much to and a car that was so often on the line for its survival.
Finally, on November 18, 1992, the new chief of Corvette engineering was Dave Hill. Since then, McLellan has been a much sought after automotive consultant, he wrote and illustrated “Corvette From the Inside” and he’s a frequent and revered guest of honor at all of the top Corvette events. In 1999 McLellan was inducted into the National Corvette Museum’s Hall of Fame. McLellan goes down in the Corvette history books as the second of the five great Corvette chief engineers. – 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.
Image: GM Archives
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.
Image: CorvetteForum.com
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.
Image: GM Archives
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.
Illustration & Graphics – K. Scott Teeters
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.
Image: GM Archives
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.
Illustration & Graphics – K. Scott Teeters
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
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
August 31, 1992– Dave McLellan accepts early retirement and steps down after 18 years as the Corvette’s second Chief of Engineering.
General Motors had a mandatory, “retirement at 65” policy, so as Corvette Chief Engineer Zora Arkus-Duntov was nearing retirement in January 1975 the big question was who would be chosen to fill Zora’s big shoes. Duntov was not consulted about his replacement and McLellan would not have been his choice, but Dave was definitely the man for the job. McLellan was an Alfred P. Slone Fellow with a degree in engineering and management. The ‘70s was not a fun time and there were serious issues to be dealt with besides horsepower, racing, and mid-engine designs. There were emissions and quality control issues, as well as the implantation of a new assembly plant and an all-new Corvette to be designed and developed.
Along with ushering in the Corvette into the digital age of computer controls and guiding the design and development of the C4, the ZR-1 was arguably one of Dave McLellan’s biggest achievements.
When the C4 Corvette came out it received rave reviews – “The Best Vette Yet!” and under McLellan’s leadership kept getting better and better every year. By the late 80s, performance was back to late 1960s levels, Continue reading “
Corvette Timeline Tales: August 31, 1992 the 2nd Corvette Chief Engineer, Dave McLellan retires” →
