I've always felt that the one ounce tank and most laps in a given time was supposed to make venturi measuring a moot point. You could open up the venturi and make more pit stops if that's the strategy you want.
This bidness of changing from a one-engine to a two-engine rule will be an education. Either the Brodak will beat the OS into the ground or it won't.
The wheel weaves
As the wheels wills
And none can see the pattern
Until it is done.
Have you ever seen a venturi, spray bar, or fuel tank measured at The Brodak?
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On the same theme, in Brodak Foxberg, they allow a Fox 35 Stunt, which has a die cast venturi throat and 35 cubic inches to run against Brodak 25's with a certain selection of CL venturis and an LA25 which generally comes as an RC engine and leaves the CL venturi/NVA to the imagination of the user. So how could one make a rule that fairly equalizes these three engines?
The de factor rule seems to be: "Air is free, and a suction engine can only suck in a limted amount, so just race and ignore trying to measure venturis". A Buster of a Flite Streak with a 25 or Fox Stunt isn't going to go all that fast anyway.