[sb01box]

Originally Posted by blue2000s

Attached is a picture of a CFD (fluid dynamic modeling) model that I ran to illustrate what's actually going on in the "T". No offense to Pedro at all with the following description, I'd just like to help clear things up a bit.

The center of the air channel from the throttle body will enter the "T" and stagnate (stop) as it hits the back wall. This builds a "wedge" of high pressure air at the center of the "T". This essentially does automatically what the little plastic wedge of the technotorque does.

The shape of the wedge created by the air itself isn't necessarily ideal and will change with flow and time, so the shape of the technotorque may help to slightly improve flow, but without analysis and testing of several iterations (like CFD or a flow bench), it's lucky if it does. It can just as easily impede the airflow and hurt power.

I believe that the polishing of the runner probably has as much (if not more) to do with the power improvement than the wedge itself.

Now notice that the flow as it goes sideways entering the horizontal tube, flattens out. Leaving more than half the tube to useless recirculation. The flow at the "top" of the horizontal tube in the picture actually just flows in a big circle! We call that recirculation. This increases the air velocity, leading to pressure losses in the junction.

The big benefit to the IPD plenum isn't the wedge at the base of the "T", it's the fact that the vertical tube in my picture gradually gets wider before opening into the T and has nice, rounded edges as it transitions to the horizontal. This helps the air to make the 90 degree turn while better sicking to the walls of the tube. This makes MUCH better use of the horizontal tube volume and significantly lowers the overall pressure drop through the "T".

BTW - The plenum is the shape it is for manufacturing simplicity and cost. There isn't enough of a benefit to power or drive-ability to justify the extra cost of optimizing the part from a manufacturer's perspective. Porsche went as far as they saw prudent with cost for performance in mind. So don't think everything's perfect with this car, it's as good as Porsche decided to make it considering the costs of manufacture.

I'm not good at fluid dynamics - but would the analysis paint a different picture for pressure versus suction?