The heat shield on the tube was an experiment. He took it off of his car soon after the picture was taken. However, the heat shield inside the box did show a tremendous temp difference. Last summer when he finished this project he put a high temp thermometer inside the engine compartment and ran it down the road about 10 miles. The temp inside the engine bay was around 190. He then placed the thermometer inside the air box with the heat shield and ran the car back. Once he got out of the car the thermometer was reading close to 110. However, we suspect that the temperature may have been less while driving since more air is being pushed into the box. The outside temperature last summer when he did the experiment was about 87 with 50% humidity. So, it was a hot and humid day to say the least.