need help with box

[loudferio13 0]

hi there just bought a fully loaded 15" btl. i used my original box that my audiopipe txxa-15bl was in. the box is 3.5"cu with 36 sq inches of port 2X18. the box is 3.5 before i put the btl in it so its actually less then that. i think the box is to small its in a 98 civic sedan. my wires are 4 guage i know i need to upgrade and a new battery and new alt. but was wondering if i could get a box design ffor maybe 4.5 or even 5 cubes design if anyone had it for this sub. another thing what is a good line driver.