Ooohh like that idea, have you made an adapter for the inlet registration?[/QUOTE]
I am going to make a plug from the end of the front duct, to the DS 75 fan.
the plug will be CNC, i will make a horizontal split lay-up from the plug, this is so that it can be removed. this will allow me to make the inner duct smooth and level.
i know there are easer options but it has to be the best way posable.
Long 155 mm
duct end 134 mm
DS 75 110 mm