It is not a good idea because you are, in essence, sucking in hot air from the engine bay, essentially hurting performance. I would look into something that will allow you to channel the air from outside the engine bay, such as a needswings or alternative design CAI. If you do not want to go this route, I would keep it stock and install some high flow K&N filters in the stock air box, you will get a small gain and better breathing this way as well.....