Tuft testing cowl

[longline]

For a variety of reasons I am exploring the installation of a NACA duct in my RV8 cowl. The logical place for it is on the right side of the cowl, lower than the exhaust pipes. I suppose it could be almost all the way down, close to the vertical induction "bump", but it remains to be seem just where it can go.

My question is if anyone has tuft tested that portion of an RV8/6/7 cowl, and what was found? I am guessing that the further forward you go on the cowl the higher the local pressure is, but do not know that for certain. DanH posted some pressure graphs awhile back, but they were pretty specific for the forward cowl and intake area.

By inspection it is apparent that there is not a flat spot on the cowl that would accept a ready made NACA duct, so it would have to be a custom thing. I do not know the aerodynamic ramifications of a NACA duct on a complex curve, and ask if anyone has any input.

Thanks