When you say hydrosystem, you talking about the CAI right? I assume you are. The side of the MAF is a little bit smaller than a 2.5" mount. The TB is also a little bit smaller than a 2.5" mount. It would only make sense to put the same size pipe between the two for the most velocity, right? I believe that the longer the pipe allows the velocity to be there and in turn once you get into the higher rpms, the air moves quickly into the TB without restriction or flow problems. On the other side of the MAF is the factory 3" opening which I assume is there just to get the air there first to get proper air flow readings. Now compared to most of the other cold air intakes out there, most of them use a 3" mid pipe that is short. How would that increase velocity? You go from 2.5" openings to a 3" pipe. Imagine if you had a 2" muffler and a 2" glasspack then you upgrade the piping to 3" in between, you loose torque.
Anyone have mathmatical statistics and details that could verify or unverify my information? I'm just using some common sense mixed with other information. Just like they say to use a 2" exhaust for the GA but yet if you use a 2-1/4" piping, you'll loose torque and velocity.