The Callaway "Sledgehammer", a heavily modified 1988 Corvette C4, became the fastest street-legal car in the world with a top ...

and a “4+3-speed” transmission (a four-speed manual paired with an automatic overdrive for the top three gears). The C4 Corvette also brought about several improvements on the tech front: it was the ...

that original C4 came with a weird "Doug Nash" four-speed that forced drivers into higher gears during shifts to achieve higher fuel economy, a concept generally foreign to most Corvette owners.