For sale if you want, same as Moomin’s system
That is an epic setup, anyone who doesn’t want to charge cool should buy it 
love you
The thread that never dies…
I have run some test using a Test 512.
https://www.testo.com/product/0560+5126/testo-512-Pressure-and-flow-velocity-measuring-instrument-0-to-2-hPa
Since flow is turbulent in both roof scoop and side ducts the anemometers we normally use at work will not give a good reading.
The idea would then be to rank air flow across the IC core (Forge IC) by measuring the pressure differential.
The intended set up was to get readings for 50, 70, 90, 110 and 130 km/h and do this for Roof Scoop only (std small scoop roof), 2x4" side ducts only, and both Roof and Side ducts.
After the first runs i thought something was wrong - I got very small pressure diffs across the core, and i got a lot of noise (or variation). Checked with people at work who do this type of thing daily, and a was doing it correct and the instrument has been calibrated recently.
Tried again and got the same readings. Lagre variation is probably due to that there is a large variation in momentary pressure in the system. I could probably have changed the setting to get some sort of moving average but I did not.
- Roof + Side ducts is giving the highest pressure diff across the core, but still very low.
- Side ducts only
- Roof only
The conclusion I make is this:
Flow is not limited by my Forge IC even with Roof Scoop and 2x4" ducts.
Flow does not seem to go backwards out through the roof scoop when side ducts are in place as have been suggested as a possibility.
Oter ways of assessing flow should be considered.
Use tell tales …
4 inch pieces of red wool taped at intervals wherever you want to see airflow .
it’s the way a 747 was designed !
attach a gopro cam to record results.