The Speiss Supercar was commissioned by Robert Speiss to be constructed in his private factory in Gemmingen, Germany. Already a successful supplier of generators to industry, Mr. Speiss hired Karl Heinz Knapp to engineer and produce the world’s first all-carbon composite sports GT car.

Callaway was hired to design and produce the engine package based on its experience with the twin turbo Corvette program for GM. Full compliance with EC regulations, 600 bhp / 600 lb-ft torque, bespoke configuration and production quality control were all requirements of the program. Unique intake manifolding, twin AiResearch turbochargers, and specially cast exhaust manifolds resulted in a svelte package. The project was cancelled before production began. However, the vehicle did meet all of its technical objectives.