For any intake you almost always want to have the coolest, highest pressure air entering possible, in order to make the most power.I have spent the morning talking with CERMA John on this matter. He illuminated several mis-conceptions and pointed out many of the things you've illustrated about Turbo's preferring to DRAW from cooled lower pressure air. vs higher pressure Laminar flow.
-He also gave me some ideas/principles on making that "low" pressure drop..,-- TANK, we will call it.
So far Im gleaning it is ideal:
- For high pressure Laminar flow air to rush in, be constricted slightly, then experience a pressure drop.
- This same area of pressure drop JOHN said is ideal for the 90 bend.
- The bend itself coupled with a dimpled or rough interior and a wide girth causes the good kind of turbulence and acutal temperature reduction.
He stated the turbines capacity is its wheel setup, that is the controlling factor on how much air. He told me one CAN NOT force air into the turbine. It sucks the air in relative to its fin and speed.
So under the best case scenario my intake will.
-Drop the pressure of the air in the draw tank relative to the incoming Laminar flow at the cone.
This is cool.
Time and experimentation will tell.
Guess I can come up with a system and head to head it with the Godzilla which is just big ole smooth piping and massive air cone. LOL!!!
The tank you're referring to is called an intake plenum or anti-surge tank. They work well if implemented properly. Some cars have them and some do not. Most if not all do not have one large enough as the focus is emissions and economy not performance or raw power. The VT has one on the intake mani under pressure and the other in the form of the oem airbox.
The larger diameter upper intakes out there act as if a surge tank were on a smaller intake pipe, yet are one big smooth flowing pipe. This has low pressure drop/higher pressure in the pipe, thus why you would have the best throttle response and power from the larger pipe. Having a surge tank on an already large piping should further help with pressure drop.
You ideally want pressurized air entering the surge area to help fill the volume as quickly as possible. This can all be accomplished, but takes a lot of work, knowledge, and testing. Not as easy as throwing something together and done.
RE the 90, bends are not ideal anywhere, especially in area of low pressure. Higher pressure will help air flow through the pipes where restrictions are, such as a bend or smaller diameters.
Also a slightly rough surface creates a boundary layer of air in the pipe, decreasing resistance to flow, thus enabling more flow. Temperature reductions are also possible however difficult to measure or prove.
Also the limiting factor of air through the turbo itself is the area it has to pass between the comp wheel fins and the comp housing. And you can force air through this area and does not have to be drawn through.
My experience in turbos has been in setups that have flowed 60lb/min on the low end to well over 200lb/min on the high end. Same concepts apply to our setup, just in smaller forms.