Hey man i think I found a calc to measure the bracing

http://www.eatel.net/~amptech/elecdisc/spboxnew2.htm

Its towards the bottom.

So tomarrow im going to start a box thats going to be 5 cu/ft after bracing and the space the port takes up. The port is going to b 15" tall 3" wide 16.7" into the box. This will tune the box to 32 Hz. All this is correct right??

Also, If I make the subs face the rear...What way should the port b facing? Maybe ill point the subs up and the port fire up also? Does it matter?