Troubleshooting Sanding Downdraft Table

[JulieR]

Can I get some help with my sanding table, I am trying to get maximum suction, here are the details and questions.
The table top is about 25" x 43" and is pegboard sitting in a rabbet, not glued down or attached. I have cut some larger holes in the pegboard. The inner box has a slanted floor leading to 6" pipe which then heads up to a gate and continues in 6" piping to the Cyclone. This should all be clear in the attached photos.
Questions: should I cut more larger holes in the pegboard? Would blocking off some of the pegboard or the table itself at the right end help with suction?

 

[Sawdust]

I have found that bigger holes don't work for me. I have used a ceiling vent that has 1/4 inch holes very close together and it does not do as good as pegboard with the holes a little farther apart and not as many holes. I prefer the pegboard using my CV-EF5 Cyclone. The dust seems to settle on top of the pegboard but is easily brushed in. I don't get any dust flying around it stays there or goes into the bin. My setup is similar to yours. I'm using 4 inch hose connected to a 6 inch line. My table top is approx 14 X 24 and is built into my work bench. To use my workbench I place a piece of 1/2 Baltic Burch the length of my work bench to cover the sanding station. I also have a shutoff for the vacuum on the 4" hose. So far works okay for me.