Listen, I understand your concerns. I had some reservations, too. However, as I stated, I'm running a K&N panel filter, so if it does end up getting dirty more often, I'll just whip it out and clean it more often. That's a quick, simple task. Other than a new can of K&N cleaner and oil every few changes, there still isn't much more cost involved - especially as compared to fitting an aftermarket CAI, ram, etc., as you suggested.
As I posted last night on another "mileage" post:

 

Thanks a lot for the diagram, Tomas. Hopefully that will help clarify what I'm talking about.

 

Interesting.....

I too am in SoCal and H2O is of no real concern.

 

To make things even more interesting, I just got my first "over 400" tank last night!
406 miles @ 37.42 mpg!

 

Wouldnt this mod make the engine run lean?
Would it have a neg. effect on low end torque?

 

hey if this works for you, i reckon it's worth a try. and it costs nothing!
406 miles! that's impressive, here's another for you

to take the snorkel off, you unscrew the bit holding the snorkel to the airbox?

 

Interesting MPG test. Its not a box, but then again its not exactly aerodynamic either, so I think there is some relevance:
http://www.omninerd.com/2006/07/16/articles/57

 

the box aerodynamics is equal to the 2006 corvette though remember

 

Top that bad boy off and see how far you go, but be warned...once you go to the top you never go back, lol

keep us posted BoxOff.

 

Excellent link, Heathen. :D Facts and figures instead of 'seat-of-the-pants' guesses. (This is also one reason that simply hooking up a ScanGuage II in my box has given me a 7-10% increase in MPG - I pay better attention to what I'm asking the engine to do.)

Snowromance, there is one additional thing that is NOT shown by just quoting the "Coefficient of drag" of the shape moving through air, and that is the effect of the frontal area.

To make it a simple example, imagine an xB then imagine an xB twice as large. The one twice as large will have four times the frontal area and the actual energy required to punch that size hole in the air is greater.

So, with a drag coefficient figure one also needs to consider the frontal area of the vehicle. For example, the xB has a better Cd than a New Beetle (Kamm effect), but I believe the New Beetle has a considerably lower frontal area - it might take less power (fuel) to punch bugs size holes in the air than box size holes...

If someone finds the drag coefficient AND the frontal area combined to show actual drag for a large list of vehicles, I'd love to see that.

All I've spotted so far is some "example" lists like this:



Tom

 

Tomas, this would be a nice place to show that xB going through the air diagram. The one showing the airflow over it and such. I always get a nice giggle out of that pic.

 

No, the only screw is near the open end of the snorkle up by your battery. The end attached to the airbox just pulls off.
Good luck!

 

THIS one, bB2NER?



Tom

 

This is/was a common mod on older watercooled VWs too. The older VWs had some of the fuel injection components mounted over the air cleaner, so a CAI wasn't possible. The only alternative until recently was to open up the air filter box. Helped power on my car, butt dyno anyways.
Oak, where did you find the Blitz unit. I looked at their website and it looks interesting. Similar to a Eurosport part for the older VWs. Also looks like it allows for a larger filter for even more airflow, right??

 

Yep! Thanks Tom!

 

Only problem with the Blitz design is it draws in hot air from over the transmission area. A better choice would be a short ram that draws cool air from in front of the drivers wheelwell area.

 

That one cracks me up every time!

 

That may be true, but at the same time I don't think that there is going to be true cool air anywhere within the engine compartment/underhood area. If the car is moving there should be a constant air movement anyways, right? Most racing cars that I've seen manage without a CAI type of setup, so there must be a reason why those filtration systems haven't made it into the racing arena.
Besides, I just like the look of that system better than typical CAIs.

 

ah i see. thanx tomas

 

Just to expand on Tomas' entry, here are a few more Cd numbers, these calculated with the inclusion of the frontal area formula:

Drag area ( Cd x Ft2)

* 5.76 - 1968 Toyota 2000GT
* 5.92 - 1994 Porsche 911 Speedster
* 5.88 - 1990 Nissan 240SX
* 6.24 - 2004 Toyota Prius
* 6.27 - 1986 Porsche 911 Carrera
* 6.57 - 1985 Chevrolet Corvette
* 6.77 - 1995 BMW M3
* 6.79 - 1993 Corolla DX
* 6.96 - 1988 Porsche 944 S
* 7.02 - 1992 BMW 325I
* 7.10 - Saab 900
* 7.48 - 1993 Chevrolet Camaro Z28
* 7.57 - 1992 Toyota Camry
* 8.70 - 1990 Volvo 740 Turbo
* 8.71 - 1991 Buick LeSabre Limited
* 9.54 - 1992 Chevy Caprice Wagon
* 10.7 - 1992 Chevrolet S-10 Blazer
* 26.3 - Hummer H2

Unfortunately, I haven't found the frontal area info for the xB as yet. If anybody's got it, please let me know.