There was also a little old-
fashioned design ingenuity. Early on, says David Currier, who led the seven-man design team, it became clear that Nascar's design parameters for the valvetrain, which helps control fuel intake and exhaust, was the engine's weak link, as it was conceived to handle a modest 5,000 rpm. To circumvent Nascar's valvetrain restrictions, TRD minimized the stroke. By shortening the distance traveled by the piston, they ended up with an engine that should spin faster than 9,000 rpm.