I checked with my "Puff-O-meter" before I installed this preliminary
filter on my van.  I had a couple of filters laying on my bench...a fresh
Vanagon stock canister one, two or three of those clear plastic FLAPs
available ones and that extra spare left over from a previously owned
Triumph Daytona 900 triple bike.

  Blowing through them to 'asses' the resistance.   The smaller clear
plastic ones, similar to the square vanagon pre-filters, those didn't allow
air through as easily as the Vanagon standard can.   The other one, the one
I selected,  that one seemed to allow at least as much passage of air,
gauged by my "puff-o-meter"...All very scientific, this.

  If you guys think I made a big mistake...OK then.  But I'll probably keep
it like this even so...When I got this van I had to replace my fuel pump
within a few weeks and when I ran some compressed air through that old one,
backwards...all kinds of gunk blew out of it...Not good.

On Mon, Jul 22, 2013 at 10:56 PM, David Beierl <dbeierl@attglobal.net>wrote:

> At 11:37 PM 7/22/2013, Don Hanson wrote:
>
>> and outlet are the same size as the post-pump filterr..  The gas flow has
>> to be similar between a 900cc high-performance motorbike at 32O lbs and a
>> ~2000cc vehicle weighing 4000lbs.
>>
>
> The gas flow here is basically unrelated to anything the engine is doing.
>  The flow rate is a minimum of sixty liters per hour continuous the entire
> time the engine is running.  That's the specified minimum output of the
> fuel pump.  The fuel pump circulates at least one full fuel tank through
> the piping every hour, and the engine sips more-or-less delicately from the
> flood as it goes rushing by.
>
> Maybe the motorcycle does it that way too, maybe not.  But there's no has
> to be about it.
>
> Yours,
> David
>