It's a good question. For all that I admire the balls-to-the-wall madness of Redline and the futurism of Akira, I think calling either cyberpunk is a more dubious proposition than even WarGames. Just about the only thing about Redline that I'd consider cyberpunk is that the drivers are largely corp-sponsored IIRC, but I wouldn't call any strict racing movie that eschews a wider societal perspective cyberpunk. I mean, I wouldn't count a hypothetical WipeOut movie either, if it was basically just one long "Formula 1 race, but anti gravity with weapons" flick. Akira... Does have some cyberpunk elements initially, but quickly abandons them in favor of completely different considerations. That's not criticism - I just think its main focus lies elsewhere.

Edit: To follow up on the tangent of borderline cases, I'd personally lean more towards movies that, while not set in a cyberpunk context, nevertheless treat central themes of the genre and has the right "vibe". Things like Limitless and Pi comes to mind.

Indeed.