[pajeepman]

I just picked up a new K&N panel filter I am gonna install in my 2000 2.0 manual tranny beetle. There are tons of posts about what to do to possibly help the engine breath better. Sounds like I should remove the snowbox.
Also read something about swiss cheesing the bottom of the airbox. Saw something about trimming the inside of the airbox. Just read something about the last 2 but didn't find any posts about it. Sounds like the swiss cheese is to take hole saw to the bottom of the airbox and drill a few large holes in it, clean the edges up smooth and reinstall it. Would a bunch of small holes be better? I'm guessing once I open the airbox up, I'll see what flashing and braces and whatever to trim out.

The good thing is I took the beetle to get the oil changed at a chain place(low on time before a trip). Big mistake. They said to use sythetic only, even though my manual says either. I wasn't paying their $70 synthetic price. The "tech" also broke the airbox lid checking the air filter. I went back and bitched and they got me a whole used box setup so I can screw around with the broken one first. Stupid tech said he didn't check the air filter, even though he broke it and din't put it back on right dumbazz.

 

[red99]

Here is a post that has a good picture of the snowbox:

http://newbeetle.org/forums/technical-modifications/4103-anyone-has-pictures-what-snowbox.html

There are basically three pieces of ductwork before the air filter housing. Going from the air filter backwards they are: first piece goes from the airbox to the inside of the fender, second piece is U-shaped and has a wire mesh "filter" in it and the third piece moves the air intake to a position inside the fender high above the front wheel. I plan to remove the second and third pieces and see if there any improvement is power by making measurements with my scan tool.

I have used a K&N filter in the past but have gone back to the standard paper filter. I didn't like the amount of oil in the intake and the more frequent cleaning of the MAF.

Some people advocate removing the venturi-shaped tube under the air filter so I decided to run a test. I figured the engineers wouldn't put it there for no reason so I measured the time to accelerate between 2000 and 3000 rpm in 5th gear and 3000-5000 rpm in 3rd gear on the same stretch of flat road. The 2000-3000 rpm time was the same with and without the tube. The 3000-5000 rpm time was about 1/4 second faster with the tube. I think that piece makes the intake act like a tuned pipe, actually improving the airflow.

So I would caution you to be careful when you make "improvements" and actually try to measure to confirm your changes had the desired effect. Any changes are likely to be fairly small and you have to weigh that against the possible downsides that the changes could have.