Honda has finally cracked open the door on what it describes as the “secret” changes hidden inside its new-spec Formula 1 power unit. The combustion 'secret' Honda is willing to shareHonda chief F1 engineer Shintaro Orihara spoke with unusual openness about the project, while making it clear that much remains under wraps. We changed the pre-chamber to make combustion faster, and we also changed the piston shape to get good combustion,” he added. Honda has partially lifted the veil, revealing faster combustion, redesigned pistons and reduced friction. But after months of struggle, Honda has made one thing clear – it believes the next chapter of its Aston Martin partnership starts now.