is there a difference between the tickford snorkel, the xr8 snorkel and the ss induction snorkel? have you only tested the intake with one snorkel?

Ford AU Falcon
This box uses a very large filter having an area of no less than 510 square cm. The inlet to the box is in the lower half, with this duct having a diameter of 80mm. The outlet duct has a moulded-in plastic bellmouth but its outlet ID is only 58mm. However, the outlet assembly unbolts from the airbox revealing that the actual outlet hole can be as much as 80mm in diameter! The lid clips to the base that is heavily curved to match the inner wheel arch area. The box is 380 x 280 x 310mm and costs $58 for the lid and $65 for the tray (new prices from Ford). Clips are used to hold the box together.

The large size of the filter meant that this box flowed quite well, with a filtered cfm rating of 93. However, it's interesting to note that fitting the filter caused a substantial flow drop of 17 per cent.

Flow of box with filter: 93 cfm

Conclusion: Amongst the better airboxes for flow, but see below for how to make a dramatic improvement!

Ford EF Falcon
This box uses the same lower half as the AU Falcon box mentioned above, however the EF lid has a much better integrated exit duct. This duct starts with a well-designed 50mm bellmouth deep inside the lid that grows in diameter to 80mm as it leaves the box. In the photo above, the EF upper half is on the left and the AU on the right. The filter used is the same as the AU, with a 510 square cm area. The box is 380 x 280 x 310mm and the EF lid costs $64 from Ford.

This is a much better flowing design than the AU box. The flow with the filter fitted was 110 cfm, up over the AU box by a very substantial 18 per cent! Even more importantly, the filter caused only a 3 per cent flow decrease, rather than the 17 per cent decrease that occurred when the same filter was fitted to the AU box. This is probably because the outlet duct draws from the centre of the filter rather than one end of the box, in addition to its bigger final diameter. It would therefore appear that swapping an EF lid onto your brand new AU Falcon can improve box airflow by 18 per cent!

Flow of box with filter: 110 cfm

Conclusion: The second-best flowing airbox after the de-snorkled VS Commodore. However, at $24.50 (Ryco), the filters are not as cheap as those for the Holden boxes.

O, and just to partner the above graph:

http://us1.webpublications.com.au/static/images/articles/i0/0073_13lo.jpg

As you can see the filter in the Falcon air boxs is really poor flowing from factory, it takes the air box that was flowing 2nd and 4th down to 5th and 6th once the filter is fitted. They were using Ryco filters, it would be interesting to see if a K&N or other high flow replacement would make a difference (Autospeed are very against replacing the standard filter with a high flow unit, they say in otherarticles it does squat).

that graph shows the flow of the airbox when no filter is fitted. As you can see the AU and EF airboxs are pretty close when no filter is being used. But when a paper filter is put in the EF only loses 3% flow where the AU/EL airbox loses heaps as shown in the first graph.

cheers........