It has variable inlet cam timing, giving 25 degrees of variation to improve torque and give a more linear power delivery.
This means that special setting tools are required to establish the cam timing before the pulley fixings are tightened.
Sprockets with vernier adjusters were fitted to allow for chain wear, and the cam timing was supposed to be checked every 6000 miles.
Both offer variable cam timing, though only the turbo version varies both the intake and exhaust valves.
The variable cam timing may be disconnected altogether.
Additional changes stretch to "rotating masses lightened, lubrication improved and cam timing altered".
That motor has a single cam per bank, so it is dual-equal variable cam timing.
It includes continuously variable cam timing (fixed overlap).
Camshafts and cam timing were also revised for the new, higher rpm powerband.
This allows continuous adjustment of the cam timing (although many early systems only used discrete adjustment), however the duration and lift cannot be adjusted.