Yes for pulse tuning effects the runners need to be very long. For optimum high rev performance you need a decent plenum and runner diameter. With stock packaging (hood, radiator/fans) the "right stuff" won't fit.
A web search comes up with numerous shops doing full 3D scans into whatever file format you wish. I have no cad/flow tools, so what is the preferred file for flow analysis?
Stock runners do fit, but a huge restriction. You can 3d scan the outside, but the inside is problematic. From a design standpoint a clean slate is needed. The resonance points with the changeover can be approximated but not calculated exactly with the stock geometry.
Bleed green and you will get somewhere.
A really good dynamic model is big time/$. The basic physical dimensionin is the easy part. To do dynamic flow as the cyls interact/pulse is going to take quite awhile to model.
I know Josh cut that one manifold off to document the choke point past the plugs, but I dont remember an area measurement of it. Thats a good place to start.
If I were you, I would not spend my resources chasing time accurate CFD results (and this is coming from a guy who runs CFD for a living and writes CFD for fun). I would start with 1D hand calcs to try to get in the ball park on runner lengths, cross sectional area targets, etc. These will tell you if your design is even feasible.
If/when you get into CFD use it to optimize plenum shapes, plenum to runner transitions, runner to flange transitions, and so on.
Section cuts every few inches on a stock intake manifold would be a great way to quickly identify short comings.
So you run CFD for a living? Have you ever modeled a Helmholtz resonator on an intake?
What I'm hoping to convey is, you'll get the most bang for your buck from a quick hand calc. You may find some additional performance from a reduced order, steady state CFD to optimize certain regions of the manifold. I don't think you will get any benefit from chasing resonance modelling or time accurate boundary conditions (valves opening and closing). That kind of work is better suited for academia where people can spend years of their life trying to correlate a single CFD model to a lab test result.
The problem with a 3d scan of the stock manifold is that the model won't be parametric, so it won't be much help to you when you go to create an updated design. You would also likely have to simplify the geometry considerably to go from a 3d scan to a CFD grid.
Changing the diameter doesn't change the resonance point (rpm). It will change the bulk velocity and profile, but that's it.
From a practical standpoint I would:
Make a "high rpm" long runner manifold and make sure it meets those needs. Modify/redesign as needed.
Then try and add the resonance chamber using the stock design as a starting point.
Unless you get the high rpm part working, why do anything at all...
No you are right.
Its all in there.
Making the torque pipes flow and adding the resonance chamber later seems tough. I would still figure out the right high flow design from a length and plenum perspective then go back and try and make a chambered manifold.
You might revisit this now that 3d printers are all over the place. A "hacker space" would love to work on something like this and ford uses 3d printers for its prototype intakes because they're cheap and fast, so the plastics must be strong enough.
I came to the party late so i cant see the pictures since they're missing.
Also what is the likely hood that the Performance Port Valve fails to open or close in the current manifold? Being its vacuum based and doesn't seem to have a electrical value to monitor (that i can tell), any obstruction or slight leak could keep it closed or open.
The real world dyno results show the effects of each and its a bit scary.