You have to contain the inlet air - the flow intensity will depend on outlet low pressure setup.
the setup I used here - is held to motor box with four #2 skt head screws -comes off in a minute -but has never unintentionally loosened
If you want to glue stuff into cowl - use clear silicone rubber on cleaned glass surface - make little angles in any plates at their bases to provide good support. epoxy or goo can cause dimpling which will show on outside of cowl.