911rudy

I modified my original air box because it still lets the breather hoses hook up to the original pipes. It also opens up the entire side of the engine bay.

SteveMB

Looks nice! Did you weld in an adapter plate?

Gino

the unit I purchased was from Autozone... Spectre Air Cleaner#4780... it came with the lower flange (now with a notch) and paper filter (being replaced w/ K&N), and chromed top (now with 2 more holes).

I found the K&N filter to fit... #E-3340 (5-1/4" ID, 6-1/4" OD, 3-1/4" high) and there is also a 4" high filter with the same ID-OD attributes, but I'm not quite sure it will clear the required space.

the K&N (3340) is $24 (3344) is $26, the original unit was about $25.

gotta do the dinner thing, but I'll be back w/ photos latta

Gino

hopefully these came out well enough to see the notch, the 2 new holes and such...

E-man930

"Someone is making a round aluminum housing with a paper element that I've seen advertised in Excellence" <== Who?
Anyone have a link to a website? Vendor? Maker?
I think we can improve on the stock airbox a bit by simply routing a aluminium duct aimed with the opening perpendicular to the openings in the wing...
On my to do list...

A930Rocket

The engine compartment should be pressurized from the cooling fan pulling in air and blowing it past the cylinders. I suppose it would do some good to fit a pipe or something to direct air into the air box, but then don't forget about water that will be forced in as well. That would have to be addressed some how.

Here's a few options for air cleaners I've seen...

911rudy

If anyone would like to modify their OEM intake I would be happy to show what I did. All of the sheet metal that I used came from the bottom portion of the intake . I used a simple 4 inch grinder with a metal cutoff blade to seperate the upper portion from the lower and then cut a square piece from the unused lower portion. I then turned the upper part on it's open (cut) end to lay ontop of the square piece and traced an outline on the flat square piece. Then add 1/2 inch to the tracing and cut it out. Use a light weight metal hammer and gently tap the 1/2 inch portion upwards all around the upper part until it fits snuggly. I forgot to tell you to drill the big hole into the flat part before you bend it to fit. After you are satisfied with the fit you can either screw, rivet or weld it together. If you don't weld it, you must use a silicone sealant to prevent air leaks. To finish it off use a thin layer of bondo along the seam, sand and paint. BTW, I put the electric fan on my condenser on a switch so that I can run the inward sucking fan without the A/C having to be on. In slow moving traffic I know it pulls more air in than the alternator fan. Also it blows directly on the intake filter. If rain is a problem there are metal shields that fit over about a 30% area of the filter but still allows unblocked air flow. I'm adding a 930S front valance, boxed rockers, and rear brake vents. I'll post a photo when done if I'm able to overcome all of the hurdles. Rudy

Brent 930

Everyone there is a reason why the stock air box and the Powerflow is designed the way it is. Rudy your air box is good but you might want to leave the oil vapor hose disconnected and use a breather. That way you have cleaner air and it won't reduce the octane rating.

jhunt@huntinter

The Powerflow needs a Helmholtz resonator.

Sameer

Whats a Helmholtz resonator?

jhunt@huntinter

That little cone inside the stock air cleaner

SteveMB

Brent930 has a valid point. Performance auto manufacturers usually go to great lengths to ensure that engine systems perform optimally. Aftermarket manufacturers lead you to believe that what they sell will give you power gains - 5%-10% is the usual claim, but as most people know those figures are well within the margin of error for the majority of power measurement equipment. The Fabspeed filter probably flows more air, judging from filter surface area comparisons, but at the expense of ingesting more heat. The stock air box draws from the right side of the engine bay where the air should be cooler. I don't think Porsche would have gone to the expense of fabricating the system they did if a simple round filter would have sufficed. It just doesn't make economic sense. OK - that's my 2 cents for the day!

Brent 930

It's the difference in how the air comes into the venturi. The air filter on top is crap, that was my point about the design. There is still a vortex with the powerflow which doesn't have the cone like John is saying.

A930Rocket

So installing a factory type cone would help the Powerflaow or the fabspeed?

jhunt@huntinter

Maybe. That is the big question.

Someone has to engineer one and do a back to back test. To date I am the only one that has done a test (that is independent of the people who sell them) of the Powerflow back to back with the stock air cleaner. The stock unit won by 10hp on my car.

I theorized that the cone in the stock unit helps with airflow and if the powerflow had a similar setup it would perform at least as well as a stock unit. But someone needs to test to know for certain.