Bi-Turbo - After listening to the video, the 2nd thing learned from McLellan " 2.Initial C4 ZR1 prototypes were turbocharged" seems to reference the Lotus engine team’s prior F1 V6 turbo project. Mr. McLellan seems to mention it as an endorsement of their capabilities, not because turbos had anything to do with the LT5’s V8 development.
Perhaps there was another part of the interview that wasn’t posted? Indeed, Chevy had investigated a twin turbo route to more C4 punch; immediately preceding the 1990 ZR1, from 1987 to 1989, Chevy dealers sold and warrantied the twin-turbo charged (stock L98 block V8) Callaway Corvette. It was the option code B2K and hundreds were sold. They had about 350 hp and over 500 lbs ft of torque. Callaway still sells via Chevy dealers: https://www.callawaycars.com/homepage/cars/callaway-corvette/
Europeans - Although Lotus certainly had the inside track since GM owned at least 60% of Lotus, it makes sense that GM would get a counter bid from Porsche Consulting. This may have even happened as part of the due diligence process as GM determined whether it was worth buying Lotus or not. Both Lotus and Porsche had pretty big consulting businesses. Think racing, as McLellan referred to with the turbo charged Lotus designs! Indeed, today McLaren’s revenues are 5-10% consulting.
Jez Stephens - ANOTHER APEX