Yes you can do that but that only lets it suck up more of the hot engine air than if you left it in the stock location. There is no way to re-route the filter that I've ever seen but what I have seen and thought of doing is having air routed to the filter. Some people place flex hose in the bottom of the bumper that run up underneath and pop out right in front of the filter. At idle this won't do anything but as you are driving it will force air up the flex hose and to the filter. Others have even gone so far as to place the filter in an enclose piece, one example being a tuperware, where the flex hoses were cut into the tuperware. This way the filter was enclosed from sucking up the hot engine air and only getting the "cool" air from the feeding hoses. Now the problems with this. Most said that by the time the outside air hit the filter it was already warm, especially since they would run in front of the radiator. Then there was the problem that most that did this never noticed any gains in power. To my knowledge it was never dyno tested but the butt dyno from those that did do it didn't show gains. The only ram air or added cool air that I ever saw that most agreed would work and the person that did it said gave some improvement was where he cut a large hole where the front license plate is. Once that was cut he made some kind of sheet metal guide plate that would guide the air coming in towards the filter. This provided a large air opening and a short route to the filter so that the air would stay cool. I believe he also used padded double stick tape on the underside of the hood so that when the hood was closed the filter was sepreated from the hot engine air. This all happened within a series of months over at Z31.com about 2 years back. You can try doing a search over there to see if it pops up or perhaps ask some of the verteran over at z31.com to see if they remember something I forgot. Basicly the outcome was ram air or exposing the filter to outside air was not worth the effort to make it work. I believe some proved using math and physics that even if you could route cooler air to the filter it wouldn't give any gains simply for the fact that by the time the air reached the engine it would already be warm partially due to the long intake pipe that goes from the filter to the TB and also due to the coolant lines in the intake system. Hope this helps
I've measured the air temps using a cold air setup with an na and get at the most maybe 8-9' over ambient in 80F weather. The coolant line thru the TB can be shut off in summer....reducing collector temps by around 10'.
It only stands to reason that if the intake air at the filter is 30-40' cooler than OEM...it will enter the cylinders 30-40' cooler than OEM since it passes the same heated areas at the same speeds.
Does it make a difference in power? Not much in warm weather...IMO.
Strangely enough...a new O2 sensor caused a noticable gain in power in warm weather...with an na.