How can I find out what my sub displacement is?
 

If I mount my sub basket out how can I find out how much more air space I have in my box? My thinking is if I decide to go ported from sealed would I get enough extra space by flipping my subs and then porting the box.

check the owners/installation manual, they usually tell you in there how much the basket takes up.

get a bucket with volume measurings on it..

stick sub into bucket of water..

subtract the final volume from initial.

I tried that and now my sub doesn't work.... DAMN.. :o).
Actually I just found out that I would need an additional .75 cubic feet to go ported and there is no way my sub displaces that.