building a ported box, need some advice

ok, so im building a 1.75 cu ft fiberglass box to share the spare tire well with the donut, and my fosgate HE 10" sub will be occupying the box. this will be my first venture out into the ported box world, and was just wondering some things. first of all, if the sub is in the spare tire well, facing up, i know it is not getting the optimum firing angle and location( eg pointed towards the back, at the back of the trunk). will this make a big enough difference to tell between the box i have now and what i am planning? second is the port location. if the speaker is facing up, would i want the port to be any certain distance from the speaker? how about pointed towards the back or the front? if i were to build a box to go in the corner of my trunk instead, would it matter which way the speaker was pointed(into the corner or towards the driver or just sideways into the trunk) and the respective direction of the port as well. thanks guys, Parker

thats alotta questions all in one. now, before any of us starts answering any of ur questions, i wanna know one thing, is your sub safe for firing upward? not all are. u might want to look into that before u start your project. 1990 Honda Civic HB:

Clarion DXZ545MP H.U.

2- 6.5" Power Acoustik interiors

Diamond Audio 600.1 amp

Diamond Audio 15" M6MKII

Pyramid PB881X 4 CH. Amp

not a clue, and i havent been able to find an answer to that either. although, i have never heard of any problems with it with this particular driver.

I could be wrong but I am under the impression that any sub can fire strait up, its down firing you have to worry about but someone correct me if I am wrong. As far as location of the sub, it can make a huge difference but I find it very hard to actually predict the outcome, Its generally a trial and error thing, which really sucks when you are fiberglassing. I would try to keep a coulpe of inches between the sub and the port but I dont think its nessasary.double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

Ports are to be on the same plane as the speaker.  1/4 diameter of the size of the sub (2.5inches in your case) and keep it away from the bottom or the "back" of the box at least 2in.  The lenght of the port will determine your  frequency.