FWIW....In my on-going series of tests, I've found there seems to be a "sweet-spot" for airflow through a Ninja. If you push more air than about 45CFM through this heat-sink, you get very little temperature improvement. This probably has something to do with the fin spacing. Remember that the Ninja is probably the best heat-sink for a low-airflow setup available today. (the 92mm Yate Loon fan I tried runs about 45CFM @12v, but is too noisy for me).
This last duct I showed was designed for a positive pressure case, with all the air exiting the case through various venting setups on the top of the case. I usually use fan-less power supplies, so this exhaust airflow at the top, helps to cool a fan-less PSU also. The little extensions to the sides of this new duct, divert some of the airflow directly at the mother-board components, and at the ram sticks........something that a ductless Ninja cannot do.
Also....the use of a 120mm fan on a Ninja seems to be un-necessary. The over-lap of a 120mm size fan, wastes the edges of the airflow, missing a Ninja completely. A 92 or 100mm fan works just as well, maybe better.
Remember that I'm trying for a quiet CPU cooling solution, designed for a system running moderate temperatures. My next tests will try out this new duct with a P4-3.4, which runs about 100W. Stay tuned.....
After more testing (different 92mm fans) I expect to install a Ninja with this "wing-duct" in this setup, replacing the Zalman 7700 cooler. That lower intake fan (120mm Scythe) is the only other fan in the case.