Quote:
Ram air flow into the snorkel creates pressure oscillations in the enclosed air cleaner, and therefore in the carburetor, upsetting the metering.
It's kind of like filling a milk jug with a hose, but each time a cylinder asks for some 'mix' it only take a scoop out of the jug....to be 'on' with ram air, you have to tune the diameter and length of intake runners to the size and length of the tube and rpm of the engine and only use it where it most helps... Also things to consider in design... any ribbing in the intake tube decreases the diameter of the intake tube as you have some turbulence at the walls of the pipe not helping flow (all the 'straight' flow is in the middle away from the walls....), any bend in the intake tube causes enough resistance to act like a longer piece of straight pipe (for us HVAC guys a 90 degree elbow is worth about 10' of straight duct of the same dimension)... your intake opening should be roughly at least 1.4-1.5 times the square inch dimension of the tube it's feeding ... lastly for best 'transition' of air from the opening to the tube, make sure the walls are 15 degrees of angle... 30 degrees at a worst case scenario... anything else just crams the air into a funnel necking down the actual intake of air....
OK time to step away from the desk and stop thinking about work....
-D.Idiot
With all this in mind, you then have to dial in your carb jetting and timing to match the intake of added air at that right time (most 'classic' cars with 'timed' ram air only opened the scoop flaps at low vacc./WOT... others just fattened up the jetting a bit for the constant rush of incoming air at high speeds....)