Before the Callaway Twin Turbo arrived, Corvette engineers were taking a shot at turbocharging a 1979 Corvette
The C7 Corvette rumor mill has been quiet the last month of so. Oh, a few weeks ago there was a burp about a possible C7 chassis mule hidden under a late model Corvette Coupe. (not much in that report) Then towards the end of May ‘11 CorvetteBlogger.com posted a report from TheDetroitBureau.com that the C7 would be powered by a turbocharged 3.0-liter V8. Of course, no one really knows except for the Chevrolet and Corvette engineers that are working on the project. But my take is that the little turbo engine report is pure speculation. There have always been those that have wanted the Corvette to be a small European-like sports car. I say, if that’s what you want, buy a Lotus.
Will Chevrolet back down from the 638-horsepower high-water-mark of the current LS9 engine? Let’s hope not. The computer emission controls on the latest LS engines seem to be more than capable of adjusting for horsepower, as we’ve seen from the work of Howard Tanner, the new “Mr. Motion” that’s building the official authorized, 800-horsepower Baldwin Motion Phase III Camaros. (Yes, I have it on excellent authority that a Phase III C6 Corvette is in the works.) What might pull the plug on a mega-horsepower C7 Corvette power plant is the CAFE (Corporate Average Fuel Efficiency) standards. But since Corvettes are a tiny percentage of the average of all GM cars, they might be able to slip in a horsepower beast into the C7 to function as their latest, greatest halo car. It’s ALL up in the air and delicious fodder for bench racing.
But the turbocharged issue is interesting and got me to remembering an earlier turbo Corvette that Chevrolet was tinkering with. Back in 1979 the above show car Corvette was powered by a 195-HP L48 engine with an AIResearch tubrocharger that bumped the power up to around 280 – 290-HP. Why they didn’t use the more stout L-82 engine, only the Corvette engineers know. Ask Dave McLellan if you get the chance. But the extra 90-to-100-horsepower didn’t WOW anyone in the already husky ‘79 Corvette. But the car sure looked cool! The silver Coupe wore production front and rear spoliers, had an interesting vent treatment on the hood, red pinstriping on the factory 8-slot aluminum wheels, and unique red & black pinstriping along the nose, hood, wheel arches, tops of the doors, and around the rear glass, plus “turbo-corvette” lettering over the front fender vents.
Overall, it was a very handsome-looking car, too bad it was a few hundred pounds lighter and had 400-horsepower for all of the turbo work. And then, there was the matter of timing. The C4 was already in development and McLellan had plenty on his plate. A few years later, McLellan spearheaded the effort to get the Callaway turbo as an official Corvette option while the engineers from the Corvette group, Lotus, and Mercury Marine were getting the 385-horsepower LT-5 ready for the ZR-1.
The inner sanctum world of Corvette R&D is an amazing and strange place. Fortunately, it’s populated with men and women that are VERY passionate about Corvettes and high-performance cars. Probably 8-out-of-10 ideas tried never make it, and of the two that do, MAYBE one will make it into production. How’d you like to get the grand tour of the R&D facility? Dream on! And I’ll be dreaming with you! – Scott
PS – There was another C3 Turbo Vette that the Corvette group was playing with that we’ll be covering soon. Plus, there was the not-so-great “Duntov Turbo that Zora wished hadn’t been made. More on that story to come!
PSS – Special thanks to Marty Schorr for the use of his article from the September/October issue of VETTE Magazine.