Petza914

Just take the dimensions from your current filters with a digital caliper - ID at opening, OD at widest base, OD at top, and length, then shop around on the filter manufacturer sites for on that has the exact ID at the attachment point and is close on the others. Whether you go oiled (K&N) or dry style is your choice. Oiled is riskier to the MAF if you don't properly oil and remove all the excess prior to running the car. On both types, I recommend a hydrophobic cover for the filters .

StormRune

It's been my guess that the Fabspeed ones are manufactured by aFe Power (http://afepower.com). Specifically their Pro Dry S line. Maybe you can contact them to see if they have direct fitment available for less dollars.

But looking inline it appears they might not save you a lot looking at others that appear similarly sized, such as some of the ones that show up in this search: http://afepower.com/products/inducti...a_material=174. While these are dry, you could also consider their oiled options.

gasongasoff

Yes, but I that would require getting my hands dirty. On that note, I wonder if there's any downside to installing a cone filter that's longer (and therefore has more surface area).

What's a hydrophobic cover?

I think you're right! But yeah, not that much cheaper, darnit.

Petza914

A pre-filter cover for the air filters with a special treatment or material that repels water to keep the filter media dry, maintaining it's filtering efficacy, but still allows for air to pass through, like this blue one

griebs

Awesome test and writeup! All these years later and the fog of war between open/ambient remains.

Well that's a big caveat! No idea regarding condition or mileage on the originals. Also, the Fabspeed uses high flow filters; it would be interesting to see the same test with equivalent BMC filters (new). The Gen1 3.6 has been dynod with the Fabspeed J version vs. factory w/BMC and the box won pretty conclusively, albeit w/questionable testing conditions:
For further argument's sake, Sharkwerks cautions against anything but the stock (mostly) ambient design, and they could surely have made $$$ on a similar aftermarket replacement. Porsche engineers have only ever used enclosed systems on their modern offerings AFAIK. Lastly, from what I've read, the engine fan kicks on pretty minimally; so, it seems any open filter design might benefit from a smaller secondary active fan.

The fabspeed sure is pretty, though-- sadly the gem of our engine bays is the filtration system. I'm looking to increase the efficiency of my puny 3.6 so placebo or boon, enjoy your extra horsies .2Sers!