Lago Blue

Sounds like fun, "Waiting for the break of day-ah-ah"!

VAP

Yep, "25 or 6 to 4" gonna be cold tho... cloudy/near 40F and 17MPH winds out of the north

odelay12v

if it makes it that far I would donate my a4 for any testing such as this . newer oem filter less than 2k 15k on o2 sensors S3 maf installed but i have hoses and an sxtb+ to install ... I would remove any of this if needed for testing purposes i know its probly along way away if it even happens but i just thought i would mention this

Lago Blue

<center><img src="http://www.eurometrix.ws/hbf1.JPG"></center><p>
...largely "straight wall" concept for the Filter-box Exit Velocity Stack vs. the Recovery Sleeve. The former appears to work by:

-increasing the <i>effective</i> entry diameter;
-straightening the air flow; &amp;
-increasing the air speed, which in turn

induces more mass flow.

While the latter may only need Bernoulli's Principal to function, and a simple constant curved wall venturi there, may provide the least restriction.

I think any significant cone wall curve in a V-stack design, may in fact choke off the air speed gain that a shallow angled, straight-walled cone, V-stack provides.

The above photo is Eurometrix's reproduction of the classic Porsche high-butterfly V-stack. Porsche's numerous &amp; apparently successful designs all seem to follow this model.

What I achieved (see photo below) was, in part, really only to eliminate from your original, the two transitions: from rim to cone (the entry); &amp; from cone to tube (the exit). The cone wall proper, now only has a slight curve:

<img src="http://pictureposter.audiworld.com/124134/b4_bucket_.jpg">

I particularly like your new design as you appear to have been able to get the entry-bell turned/rolled back further than I could with your older one (see above).

from TWM Induction:
"The full radius (entry) design is accepted by the performance industry as the best for maximum air flow." This even though they also sell non full-radius types.

They are in effect saying that the full radius type function better than the "shorty" type.


<img src="http://www.twminduction.com/AirHorn/AirHorn.imgs/williams_2.jpg">

An example of their full radius horns above; &amp; below.

<img src="http://www.twminduction.com/AirHorn/AirHorn.imgs/AirHornDimension2.gif">

Below is their <i>non</i> Full Radius "shorty" type:

<img src="http://www.twminduction.com/AirHorn/AirHorn.imgs/AirHornDimension3.gif">


I believe that the best V-stacks may require this -<i>straight</i>- cone wall feature in order to function as the classic designs all seem to share this common characteristic. Perhaps this is the missing feature that caused your curved-wall filter-box exit V-stacks to flow less favourably?

dragon-ryder

I'd be glad to participate.