Baffle inside the DC

[roadkill401]

I understand the idea of putting a pre-cyclone infront of the DC to minimize the amount of debis that hits the impeller etc.  In a perfect shop I would have the room to fit this in and all would be well.

I however don't have the room, so I am stuck with getting the best use out of my DC that I can.  My problem is that as the lower bag fills up, there is quite a large amount of pickup from allready settled particle when the unit is turned on, and as the bag gets fuller this only gets worse.

I was thinking that this design would help to reduce the amount of air turbulence send down into the lower bag by butting in a baffle to separate the incoming cyclone from what has already fallen down.  I made up a plate to fit in but am wondering about the 240deg cutout.  On the original design, this is set to 1 1/8" cutaway.  On my first test, I had made my cutaway about 1 1/2" and it still sends the cyclone down to the bottom of the plastic bag.   Has anyone experimented on reducing that cutaway to much smaller amount and what effect it has on the efficiency inside an actual DC unit?   As this is a clear plastic bag you can see everything that happens below the baffle, but not what is going on above.

Thanks

Matt.