Vacuum Cleaners Discussions

in riccars tandem air vaccum...while the direct-air motor turns the brushroll and cleans the carpet..does the clean -air motor provide any additional suction or cleaning power at the brushroll chamber...or is it only used to help filter the air out of the vac...im about to start project (franken vac 8925) .just trying to figure some stuff out b4 i start....any help, knowledge ,ideas, is more than welcome....and  appriciated

not a problem on the pics....do you think i should concentrate all suction thru the one inlet...at one end or one inlet for the dir-air mtr ,,and at the other end an inlet for the clean air mtr...that meet as one at the entrance of the bag.,,and could i use 2 in pvc pipe in place of the rectangular kind thats used in dir-air systems.....and thank you for your reply....