Hi All,

I'm in the process of rebuilding the lower cowl and ram air induction.
Several people have made comments on the size of the opening
for the ram air induction. The standard shape is like a squashed trumpet,
with the cross sectional area decreasing as the air travels inwards.
Some say the hole can be smaller and round and that will work more
efficiently.
Opening size same as fuel controller.
Is there any formula? Is there a speed at which the ram air effect becomes
constant?
Any help/advice on this matter would be most appreciated.

Michael
LNC2
VH-RMU