hey guys nothing wrong with making your own intake. Most shops start the same way you do by testing. There is companies that have spent $$ thousands of dollars R & D and still can't get it right. I not saying name of company but very large import tuner that me and two other STi owners spent over 2 weeks testing and tuning with couldn't get a sri intake and fmic to work or flow right even after hrs of tuning. they had to end up redoing the whole set up .
i know not every one can afford a big name or brand parts. So if you can do it your self then do it. Just watch what your doing and learn from it.
Im going to build my own intake , dp and catback and piping.