Am Dienstag, 25. August 2015 16:04:46 UTC+2 schrieb :
I also have a "CM" and interested in doing that-Did you only drill the 2 holes or did you add a funnel as well ? can you install the upper gas tank after this operation ?
Dan

I installed a vent (inspired by Jonkers ;-) ) on each engine bay door.
Then I drilled the two holes into the bulkhead to achieve airflow from the cockpit into the engine bay (somewhere in the middle between upper border of the main tank and the top of the fuselage.
I fixed a stainless steel mesh in front of each hole so that the stuff packed onto the turtle deck stays on the turtle deck.

I don't have the option to install the upper gas tank because I have a canopy which opens by swinging up and to the back, and the hinge + gas strut sits where the gas tank would go. However, I don't see why you couldn't fit the tank after the mod - it just eats space corresponding to the thinkness of the mesh.

Does it improve venting? Yes.
Does it improve performance? I have no way to measure that.