I had replaced this tube on my 1991 Volkswagen Vanagon GL Campmobile with 2.1 L engine with a piece of aluminum dryer duct.  It worked fine.  However, when I put in a Ten Cent Life external oil cooler, that came with a very high quality rubber snorkel to replace my jury rigged version.

mcneely

---- Dan N <dn92610@GMAIL.COM> wrote: 
> on the passenger side rear pillar there's a tube routing the fresh air in
> to the air filter box. That tube is made of reinforced cardboard, mine is
> collapsing from the inside, restricting the air flow. I took the tube out,
> remove the collapsed  material...
> 
> image of the tube:
> http://www.thesamba.com/vw/forum/album_page.php?pic_id=1267738
> 
> a look of the inside:
> http://www.thesamba.com/vw/forum/album_page.php?pic_id=1267739
> 
> On Sun, Mar 29, 2015 at 6:31 PM, Raymond Markett <raym02@yahoo.com> wrote:
> 
> > If the air filter isn't the bottleneck, then a less restrictive filter
> > won't do much good. Eyeballing the WBX intake tract makes me think the
> > throttle body is the choke point.
> >
> > Raymond
> >
> > Sent from my iPhone
> >
> > > On Mar 29, 2015, at 9:25 AM, Loren Busch <starwagen@GMAIL.COM> wrote:
> > >
> > > ​RE: K&N Filter in a WBX
> > >
> > > When I first got my '90 Westy I picked up a K&N filter.  On my first long
> > > trip I kept careful numbers on gas mileage.  at the midpoint of the trip,
> > > at about 1,300 miles, I swapped in the K&N.  When I got home I compared
> > > numbers, fresh stock air filter on the first half of the trip vs. the
> > K&N.
> > > And not a whit of difference that I could see.  I used the K&N for
> > several
> > > years but got lazy and went back to stock filters, don't have to clean
> > and
> > > oil them.  As Dennis said there have been various reports over time that
> > > the K&N does not really do that good a job as an air filter.
> >

--
David McNeely