What about doing something like some of the Supra guys do:

Shitty picture but you get the idea...open up the hole for the hot pipe and run your intake pipe down there closer to the front duct then re-route your hot pipe to come in from the side. Lots of cutting and more pipe fab but if you could get away with that very easily, and you'd be getting a lot cooler air coming in too. Or you could always do the standard move by coming off the turbo and making a 90* left to run in front of the motor. That'd give you your 18" there too.