But the real magic was under the hood. Koenig added a twin-turbo kit to the original V12 engine, transforming the Testarossa from an elegant berlinetta into a true supercar with over 700 horsepower.

That was about 13 mph faster than Porsche’s contemporary 911 Turbo, and faster than any vehicle (Ferrari Testarossa and Porsche 959 included) in the star-studded test gathering. The magazine ...