Aston Martin DBS Inlet Manifold Upgrade, the DBS manifolds have an enlarged plenum and improved flow characteristics perfect for a DB9 HP Upgrade, they produce more power at the top end but a little less low end torque. In my opinion they also look better than the stock DB9 manifolds.
Removing the manifolds is not the simplest of jobs, but they need to be removed for various other jobs such as Changing sparkplugs or coil packs, fixing the PCV system etc.
I chose to clean and check the flow rates/spray patterns of the fuel injectors when the manifolds were off.
Aston 1936 How to remove and replace Inlet manifold very thorough and detailed instructions on all the steps needed to remove and replace inlet manifolds.