I’m going to let you in on a little secret into the inner workings of The Autopian and how we put articles together. When finding appropriate images to use, we can’t just grab things from the internet and credit them, or scan images from books. We rely on images from manufacturers’ media pages, YouTube screenshots, and cars for sale. Or, we ask the original photographer for permission. As you can imagine, this sometimes gives us a bit of a headache and can result in a fair amount of back and forth in the Slack as we try and figure out whether we can use a certain picture or not. I might be a monster, but I’d rather not be the one responsible for putting Matt, David, or Jason in jail for copyright infringement, if only because I don’t want to have to bake a cake with a file in it or dress up in drag Bugs-Bunny-style to seduce the guards so the three of them can escape in the Aztek.
Because I’m British I’m automatically charming in the eyes of my American brothers and sisters, and I can put this superpower to a beneficial use. The good people at the GM Heritage Archive have helped out in the past when I wrote about the 1977 Chevrolet Caprice, the GMT400 trucks and the Pontiac Aztek. I emailed them recently in my best BBC posh accent to enquire if they possibly had any images from the C4 Corvette design process they could share, and friends once again they delivered. In spades. There was far too much good stuff to squeeze it all into the Damn Good Design piece, so a currently not-in-jail Matt agreed a follow-up would be a good idea. This is going to be quite a picture-heavy post but these priceless images will hopefully broaden your understanding of how the car design process works inside the studio. Join me then, as we head back to the brown-hued days of 1978.
I’m going to try and post these images in chronological order, first the renders and then the clay models, but not all of them are dated so bear with me as I do a bit of educated guesswork. There will be a bit of crossover between the two processes because although the flatwork is done first and then a clay started when the chief picks his preferred proposal, sometimes a design doesn’t work when you get it into 3D. A big OEM like Chevrolet will have plenty of talented designers and clay modelers to allow both to take place somewhat simultaneously, but such a prestigious and high-profile project as a new Corvette is likely to have only a select few involved. Back in Harley Earl’s and Bill Mitchell’s time in charge, they would have overseen the Corvette personally – Mitchell in particular was very protective of it – but one of the reasons GM management promoted Irv Rybicki to GM VP of Design over Mitchell’s chosen successor Chuck Jordan, is because they wanted a chief designer who would do as he was told. Jordan would have to wait until Rybicki retired in 1986 before ascending to the top job.
In The Beginning
This image is dated September 1978 and would have been an extremely early proposal because we know the C4 program kicked off in 1978 for a fall 1982 release. This and the following renders were all done in traditional mixed media: a combination of pencil, marker, watercolor, and gouache on bleed-proof paper mounted on board. The outline is done in pencil, then the main colors blocked in using marker. The ground is watercolor and gouache is used for the tiny highlights – notably on the wheel lugs and wheel arch flares. There is a lot of 3rd generation F-body influence in this proposal, particularly the B pillar.
A full-size side view render, dated 17th October 1978. This will have been outlined with tape and then airbrushed. Notice the 2nd generation Camaro wheels. There’s still a lot of C3 in this, particularly the nose and tail and belt line. The title says “1982 Corvette Front Engine.” At this point the program was still on for a 1982 release, and perhaps they were still thinking about making the C4 mid-engined.
This second proposal was obviously an early favorite because here it is in full-size clay form, dated 30th of August 1978. How did the clay come before the render? There would have been a lot of renders done, not just the one farther above. Given how close in date they are, I think the full-size side render was done to make some changes after the clay had been reviewed. Look how the front bumper area differs between the two – the render is much sharper. If you look closely at the clay model you can just about see the vents in the glazing behind the B pillar.
And on the other side, the vents have disappeared, and for some reason the right-hand side doesn’t have federally mandated marker lights either. Also, the fender badge says Corvette, rather than having the crossed flags emblem as on the other side. Quite often full-size models will have different proposals on each side of the model in what is known as A-side and B-side. This saves the time and expense of creating two separate models that might only differ in minor details. Higher-up design managers like Jordan and Rybicki would have been responsible for a lot of cars across all the GM studios, so their time would have been limited. Come the weekly or two weekly review, designers would have needed everything ready for them.
The same model again, but look at the taillights: now they have a tinted cover on them. This image is also dated 30th August 1978, so this suggests the taillight covers are just a quick mock-up, possibly a clear film simply stuck on for the purposes of this outdoor design review. One of the reasons for using physical models like this is they can be moved into a secure viewing space attached to the studio to be appraised in natural light and alongside other vehicles.
Selling The Drama
These wonderfully evocative interior sketches are by Arthur Pryde, who graduated from the Rhode Island School of Design. Pryde joined GM in 1973, staying until he retired in 2008. If you think exteriors are hard to draw, interiors are even more difficult. Although quite different in execution, both these interiors show a high-tech, driver-centered cockpit. Both of these appear to be from September 1979.
These next two images are undated. Look how dramatic they are; the designers who did these pushed the design much further than the previous renders. When you start sketching proposals for a new car, you can go one of two ways: start conservative and then get wilder, or you start really crazy and out there and wind it back towards reality with successive iterations. I’m taking an educated stab in the dark here, but I’m guessing after the silver clay pictured earlier was reviewed by senior management, it was deemed too safe and not advanced enough, and the drawings above were the result of the designers being encouraged to go back and explore more daring ideas. Irv Rybicki by his nature was quite conservative, whereas Chuck Jordan was much bolder and not averse to taking risks.
More Clays. Good Job The Stuff Can Be Reused
This unpainted clay is from early March, 1979 and is apparently a wind tunnel model. Compare the nose to the silver clay pictured above. The light units wrap around onto the fenders, a feature that wouldn’t be seen until the C4 facelift in 1990. This isn’t because they were working 11 years ahead; instead it’s more likely this was a favored direction that didn’t provide the aero efficiency they were looking for so they had to try something else. The metal tracks on the floor allow the milling head and surface point machine to move alongside the model. Digital scanning didn’t exist back then, so a small articulated pointing device connected to a computer would have been placed on the surface of the model at specific coordinates laid out in a grid to capture the surface data.
Still Not Quite There
These photos were taken exactly a year after the silver car, on August 30, 1979. Chuck Jordan and Irv Rybicki must have scheduled their design reviews for the end of each month. This is much closer to the final design, but the tail lights are not finalized – someone obviously really liked the idea of having a black graphical element on the rear, but this looks clunky. The hood is doesn’t yet have a power bulge or the feature lines it would later gain, and the openings for the pop-up headlights are not defined. The fender badge still says Turbo Corvette. The doors mirrors are much closer to the production items as well. The nose is almost finalized here.
October 31, 1979. This is getting near to the production C4 we all know and love, but there are still a few details to resolve, notably the fuel filler cap sitting proud on the surface of the rear hatch. The vents in the nose have been opened right up, suggesting they were still trying to get the aero right. The tail lights have finally shed any kind of black graphical element, but are a bit bigger than they would end up being on the real car. This car has different wheels on each side, but I’m not sure if it’s the same model as above. You can strip the paint from a clay model to rework it, but the extent of the changes here and the short timescales involved make me think it’s a different model from the other red one.
A full-size side view from January 1980. It still has a turbo badge on the fender, and the door handles have not yet changed to the more traditional lift flap-type ones the final car would have. The side mirrors are still mounted at the base of the A-pillar as well – they would end up being mounted on the door. The overall shape is basically finalized, but the detail stuff takes time because they are affected by loads of external factors – functionality, ease of construction, cost, use of carryover parts and so on.
A super-lightweight C4 proposal? No, this is an interior buck from January 1980. These are made so various parts of the interior can be reviewed in situ as they are designed, mocked up to resemble the inside of a real car. They allow you to check instrument visibility, control placement, the ergonomic relationships between wheel, seat and pedals, as well as judge the view out the windows, and consider how easily or not drivers and passegers may ingress and egress. We can tell the glazing is plastic because of how wavy the reflections from the studio lights are.
Nailed It
Another clay, probably a sign-off model, dated 23rd January 1980. The exterior design is for now all but finalized. There is a high level of detail and finish on this model, which for time and cost reasons would not be applied until getting ready for final sign-off by the board. Behind the blackboards, you can see the studio curtains are kept closed. Outside would have been the secure viewing garden, but it still doesn’t pay to take chances. This is still three years before the intended release, although it would be later pushed back to 1984 because of Lloyd Reuss’s insistence the C4 had a full targa roof instead of just T-tops, something that required a lot of re-engineering of the body in white.
I wanted to include these photos from March 1982 to demonstrate that car design is not the work of just one of two artists knocking out fancy drawings. It takes a highly skilled and dedicated team of managers, designers, and modelers to bring a car to life. The photos are labeled as a clay model being milled, but what I think is happening is the modeler is capturing the surface data point by point as I described earlier – you can see the gridlines laid out on the surface of the clay. In the second photo, you can see a scraping tool by the right headlight location. Modelers used this type of tool and others to delicately sculpt the clay by hand. In the background is a model of the third-generation Camaro.
As a car nears the end of the design process and is handed over to the development team, designers’ minds will inevitably begin to think about what fun variants could be done. This Indy 500 pace car proposal is dated 1983. This sort of thing is always a lot of fun to do. You can draw the finished car with your eyes closed by this stage, so you can let your creativity run riot with colors, graphics, additional trim pieces and even different bodywork. I had a lot of fun knocking up as many different Defender variants as I could imagine during my time with Land Rover, some with different bodywork and some special liveried versions for certain important potential customers. The 1986 C4 pace car ended up just being a simple text graphic on the door, but the 1995 version was a lot closer to this two-tone proposal.
Incredibly, this drawing still shows Twin Turbo V6 on the fender. We now have the story of how the exterior design, but when it comes to powertrains, I think the C4 still has another story to tell.
Once again I need to thank the GM Heritage Archive for providing us with these images and their help in both these Corvette C4 articles.
- The C4 Corvette ZR-1 Is The Last Affordable 90s Supercar
- A Man Loved The C4 Corvette So Much He Bought A Red One Of Every Year
- The Corvette ZR1 Has Always Been Proof America Can Build Supercars When It Wants To
- This Gives Me An Idea: 1985 Chevy Corvette vs 1988 Chevy Corvette
“Quite often full-size models will have different proposals on each side of the model in what is known as A-side and B-side. This saves the time and expense of creating two separate models that might only differ in minor details.”
Chrysler took this to heart – I have pictures in a magazine somewhere of a couple of early Valiant models that were built as running and driving prototypes with one side built as a 4 door sedan, and the other as a 2 door post coupe. (A Hyundai Veloster about 4 decades early!)
Yes this is very common practice and has been for a long time.
It is interesting how the choice of wheel and tire presentation has an effect on the overall design and how “modern” it grows as it progresses.
Slotted wheels and tall white-lettered tires are certainly 70’s vibes and the basketweave plus slick low-profile tires look like the future.
In my (soggy) mind these decisions are every bit as impactful to the overall presentation as the b-pillar angle and blacked-out taillights.
[Looking back at the pics again]:
It’s the tires entirely (ha), whether they are on the slots or the weave. That was somebody’s choice, I wonder whether it was a single leader or review committee?
It’s clear earlier on they were just using existing C3 wheels, because the C4 wheels hadn’t been designed yet. But ideally you need to get the models onto the expected wheels asap, because they do impact the look of the car and form part of the design.
These days plastic trims are used, attached to slave wheel ‘blanks’ with magnets. This allows various styles to be swapped over without the hassle of changing the actual rim. Also wheels go through many, many rounds of FEA so the design will subtly alter as this is carried out, and actual production wheels might not be available until nearer the end of the design process.
This was great! It’s so interesting to see vestiges of the C3 in the design, and now that I have seen it, looking at the final C4, I see it as the evolution of the C3, not a radially new design.
Interesting to see the drawings and clay models having smaller, thinner side running lamps and retroreflective markers instead of chunky ones with cornering lamps found on the production C4 Corvette.
That’s the sort of stuff that changes throughout the realisation part of the process, after the design is signed off. There could have been any number of reasons they ended up bigger: legislation, the smaller ones might not have been effective enough, o it wasn’t possible to get a good enough surface quality in the GRP with such a tight opening.
Thanks so much. This was fun. I love this kind of stuff
Fantastic article.
I prefer the aesthetics of the early clay model to the C4 we actually got. It looked cleaner and may have been even more slippery.
A turbo V6 like what went into the GNX would have been a very interesting powerplant as well.
If you keep posting C4 content imma do something dumb…
I’m thinking the same thing. Yellow or red?
Yellow.
for the win!
As an ex-82 Collector’s Edition owner, it’s kinda wild to see how much of my former car ended up in the C4. Partly down to the color scheme in some of these images of course, but with the long development of the C4 and the clinging-on nature of the 82CE, it feels like there’s a little more blending than just the lifting hatch glass.
Adrian, the swishy bits on the first rendering and second interior sketch are probably Flo-Master ink mixed with ground-up chalk pastel and applied with a cotton pad. Flo-Master was deadly: it made the whole studio smell like an oil refinery and, apparently, was full of lead.
The first rendering is on vellum: the greys in the glazing (also the top of the bodyside reflection and, maybe, wheels?) are black marker on the back surface.
These archive pictures are fantastic. More, please!
I was going by the descriptions on the contact sheet, but you may be right. Bit before my time.
I wish I could say the same…
Another fine article. Like a wily lawyer, you knew the right question to ask. I can’t wait to see the next.
Thank you Adrian. I enjoyed this thoroughly and get the feeling that you enjoyed putting it together.
C4s are some of my favourite Vettes, especially the updated version.
That said, I would live to see what you would fix/clean up in the design of the C5. I like the C5, but there is always something nagging at the back of my mind when I look at one, and not just the cues taken from the Ford Probe and the NSX.
The C5 is just a bit soggy and looks heavy. Chuck Jordan hated it.
It’s astonishing to me how even so many iterations deep into the design process that the car looked so tall because the refused to shorten the front overhang. The angle of the hood into the front bumper does a ton of heavy lifting to make the C4 look so lithe.
The other thing is you can see them slowly downsizing the wheel wells, from cutting into the shoulder curve of the hood to the arch lip just jutting out from the shoulder curve to the arch lip barely touching the shoulder curve to the wheel well finally being small enough to not touch it at all. Making those smaller and shaving off the flare anklets so that the wheel wells are just clean cuts into the shape instead of being extruded make it feel more compact, even though the rear of the car doesn’t change in height.
Switching the B-pillar from raked back to upright makes the car feel less ass heavy, but it’s intriguing that they tried to keep it around for so long. Since the B-pillar is ahead of the centerline of the rear wheels, the entire car feels like it’s scrunched up if the eye’s trail follows up the bumper, along the hood, along the sides, and then up and back until hitting nothing. The final C4 has a continuous trail for the eye to follow because it doesn’t perceive the B-pillar as part of the line and the rear flanks as a branching path. The C5 would go right back into stepping into that pile, though.
Considering you guys are getting these, would it be possible to get some of the designs done under the direction of Wayne Cherry? I wonder if there’s anything for his time at Vauxhall and Opel, specifically.
“I emailed them recently in my best BBC posh accent”
But your superpower is your mastery of eclectic brit slang colloquially.
Do love these professional guided tours behind the curtains! A+
I can be cutting and charming at the same time.
Enjoyed the dive into the design process. As for the subject car itself, my inner Thumper says not to comment.
This a real gem. Fantastic to see.
Thank you, glad you enjoyed it.
The undercut on the nose profile and the bumper form in the back hung around for a long time – getting rid of them did a lot (once the split line along the body side was part of the theme) to make it look more modern.
Wow, what a bomb Adrian! Wasn’t expecting this when you mentioned a follow-up.
Are those possibly the last days of true, original American design? It looks like it’s pretty much dead nowadays, blended with other influences.
That red sketch and sepia-colored sketch labelled ‘corvette’ are both awesome, totally poster-worthy. They make me think if a retro Corvette reboot would be possible with that styling and modern powertrain, in limited numbers to feed the 80’s nostalgia as evident in recent years.
Corvettes have always looked derivative of European design in some fashion. Sometimes explicity of a particular model or brand, other times as a hodge-podge of various makers’ wares.
I mean, I can’t speak for the whole commentariat, but I’d buy tickets to that movie.
Enjoyed reading this will all the insight on the different stages of design. Looking forward to the next one.
Is clay modeling still a thing? Seems like you use virtual reality to walk around the early models and pop out 3d printed versions up to 1/4 or even 1/2 scale to get you far into the design process. I am not sure how you could do a full size without clay.
Clay modelling is very much still a thing: I wrote a piece about it a while back. Even with industrial additive manufacturing machines it would take some time to knock a quarter or fifth scale model and you wouldn’t be able to alter it, which is the benefit of working in clay. VR doesn’t really work for reviews because you need to see it with your own eyes – and to touch and feel the surfaces, plus VR still cannot accurately represent natural daylight.
This is awesome!
Fantastic look in. thanks for putting all of this together.
Man, looking at that pic with the covered tail lights made me think “are we SURE this isn’t a Camaro/Firebird concept?”
Yes, probably why they didn’t proceed with that detail – it would have looked too much like a Firebird.
I know right I wonder if the third gens took design ques from the Corvette development? I haven’t looked much into that
The red ’79 model looks very much like a Firebird to my eyes (maybe it’s the wheels that’s doing it to me?), but the addition of the gills and the dual front lower openings in the ’80 seems to transform it back to Corvette.
I got that same vibe from it but I’m pretty sure it’s the wheels.