AiRaid or K&N
The only thing that comes close to a real CAI kit is a Volant type system or ram air.
Wow... do you understand anything about physics?
The heat "transfer" you are talking about... if by "transfer", you mean to allow heat to reach the air inside the kit, the only way for this "transfer" to take place is for the material the kit is made of to absorb the heat first. Once it gets hot enough by absorption, the heat reaches the air inside it. So if a certain metal absorbs heat better than a certain plastic, that same plastic cannot "transfer" more heat than the metal. This of course assumes we are talking about fully enclosed kits. The K&N type heat shield allows air above and below it, it does not seal tightly at all with much of anything around it, and so really isn't that great of a heat shield, regardless of the material its made of.
The heat "transfer" you are talking about... if by "transfer", you mean to allow heat to reach the air inside the kit, the only way for this "transfer" to take place is for the material the kit is made of to absorb the heat first. Once it gets hot enough by absorption, the heat reaches the air inside it. So if a certain metal absorbs heat better than a certain plastic, that same plastic cannot "transfer" more heat than the metal. This of course assumes we are talking about fully enclosed kits. The K&N type heat shield allows air above and below it, it does not seal tightly at all with much of anything around it, and so really isn't that great of a heat shield, regardless of the material its made of.



