High performance Violent X3 Turbo fan mod

I bought a "Violent X3 Turbo" fan to use as a replacement for an air duster. I found that it has as couple design flaws:

• The large magnet in the middle acts as an air restrictor, blocking the intake and exhaust of the fan
• An overly aggressive attachable reducing duct, causing excessive static pressure and fan stall - as a result, the pressure at the duct is actually worse than without the duct. 

The address this, this mod features:

• Magnets at the side, where they won't block airflow
• Greatly reduced cross section of intake and exhaust covers, with a “knife's edge” chamfer on grill surfaces, an internal shroud, and other small tweaks to help reduce airflow issues.
• A longer reducing duct, with no more fan stall!

 I blew the fan on a scale accurate to +/- 0.1 oz (3~ grams).

• Upgraded Duct: 5.1 oz
• Upgraded Reducer: 5.0 oz
• Stock Duct: 2.6 oz
• Stock Reducer: Unknown (it was thrown away in the trash) 

That's almost double the force generated. 

You will need six 6x2mm magnets for the reducing duct attachment.