Mitsubishi Forum - Mitsubishi Enthusiast Forums

For the stock set-up, the stock airbox is fine and it actually benefits the motor since over a RAM since it won't suck up any hot air. I would just recommend a drop-in K&N filter, but open up the intake ducting found in the passenger side fender well (right in front of the stock SMIC). A CAI will be beneficial after getting an aftermarket intercooler since the stock one will heat soak if you RUN it consistantly. Plus it may inadvertantly suck up water if you live in or drive around in high water zones. I will never recommend a RAM since it will always suck up engine bay heat and throw off intake temps...which will dump in more fuel just to keep the motor within spec temp range (think ECU). You'll just run more than stock rich at that point. A short CAI tubing, curteousy of DIY piping, will be the best set-up for cooler intake temps OR you can make an enclosure for a RAM intake filter similar to mine. My intake temps dropped 10 degrees btw.
http://memimage.cardomain.com/member...14_93_full.jpg

The hood completes the enclosure. It is by no means "sealed", but it does suck up more cool air than hot engine bay air. The opening for the stock box is also opened a bit more to allow cooler air to be sucked up from the fender opening. It would also help if you remove the blank panel right in front of IC if you don't have fogs. If you do, then no big deal (I prefer cooler air over lighting the ground directly in front of my car though ;))