While I'm still modeling stuff in 3D (I have now full access to a 3D scanner but its a pain in the ass to work with it, or I mean the post-processing is long and difficult), I've done measurements on the flow bench with the std inlet/tb and here are numbers :

Flow through the 4 cylinders : 125
Flow through cylinder 1 : 78
Flow through cylinder 2 : 85
Flow through cylinder 3 : 75
Flow through cylinder 4 : 66

Everything is given in [liters/s] and there is a diff pressure of 0.07845 [bar] between the machine and the exterior. Measurements were done using a std 4wd inlet with throttle body fully open, and blocking 3 exits when measuring the last one.

I've also measured the speeds at the exits of the inlet, just before going in the head, but its not so accurate because it is impossible to measure equally the cylinders.

So again, if you have got CAD models of other manifolds I could analyse them theoretically and see the accuracy I get with the experimentation I did on the std inlet.

And also if anybody dares to send me an aftermarket plenum/inlet I would be REALLY happy. I will pay for postage and everything.

Thanks for the reading that update ! More interesting stuff to come when I (finally) finish to make the 3D model. Again, it takes a shit lot of time because it is VERY accurate and it requires lot of work to adjust the things, and I've got lot of work to do in other courses too (Christmas rush).