Has anyone tried that yet? I am thinking if I made a 3" hole on the bottom of the can and then cut half the can off on the side, it would make a perfect heatshield. Much like the one that Injen sells for 40 bucks. My car runs like **** with the Injen on hot days

 

I don't think a metal can would be a good choice because it would absorb the heat. You need to use something like plexi or plastic (poor conductor of heat) for the best results IMHO.

 

Try PVC pipe