I use PVC pipe to feed outside "cold" air to my short ram intake. It helps power on the highway and keeps the engine bay cooler. Probably wouldn't make much of a difference in the 1/4 mile or at an auto-x, but it should on a real track.

It doesn't make a huge difference, but it's still a nice improvement on the highway. I want to make it into an actual ram air setup, but for now, it's bombarding the intake with plenty of cool air. My DC header makes things get pretty hot under the hood and the aluminum intake tube is a heat magnet. This mod helps the heat problem quite a bit, unless I'm just driving around town.