The results are in! And with some very interesting results. First off, this material will be going into a future issue of a magazine (to be mentioned at a later date) but I'm giving you guys the results first because I got the idea from you and you deserve the credit. I take the risk of somebody burning me by using the info somewhere else, so that at least oughta bring me up to Double Whopper status!
Also, in the story I will credit you guys for the mod in whatever way you think is appropriate... and is politically correct for the magazine, of course.
WARNING WILL ROBINSON!
Look close at the two closeup pics to see what happens to the downspout tube at high flow rates, so all of you that have done this may want to trim most the the excess back, leaving just enough to center it in the fenderwell hole. This problem occurred at the maximum flow rate of the housing. It may not occur to a stock truck (see 5.4L theoretical airflow below) but it's probably worth the time to fix it.
The tests were performed by two classes at the University of Northwestern Ohio's High Performance Fuels Class, at their School of High Performance Motorsports, on a Superflow SF-600 flow bench. Each class double checked each result from their class, but each class used a slightly different protocols (both standards in the industry) and I have averaged the results.
NOTE: A 5.4L V8, given 90 percent volumetric efficiency, at 5500 rpm, needs 473 cfm of air. Giving it more than it needs at any given time doesn't necessarily offer any more power. Bear that in mind when reading these results.
Condition/ Average Airflow
1- stock housing & filter, as installed in vehicle- 621 cfm
2- same as #1 but with AEM filter panel- 592.36 cfm
3- stock housing & filter but no silencer or snorkel- 656.83 cfm
4- same as #3 but with AEM panel filter- 632.50 cfm
5-
same as #1 but with snorkel tube modification- 597.3
6-
same as #5 but with rubber downspout adapter removed- 637.5 cfm
7-
same as #5 but with AEM panel filter- 569.51 cfm
8-
same as #6 but with AEM filter panel- 619.70 cfm
9- same as #3 but with silencer only- 632.50 cfm
10- Brute Force Intake (for 2004 model)- 733.30 cfm
11- AEM filter only- 1077.25 cfm
You can reach your own conclusion over what this all indicates and I will share mine later if asked
