When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Heat is energy, and yes it does require volume of exhaust gases to work. But there is a reason that keeping the turbo hot side pipe insulated and short as possible is beneficial to higher boost. Not just to keep your underhood temps down, which is a nice benefit. Pure heat by itself cannot do work, but with exhaust gas pressure, it does do work of spinning the turbine wheel. There is a drop in temp from the hot side to the exhaust side.
Compressing air causes it to heat up, so an intercooler is used to take away the heat in the intake side while maintaining the pressure. From the Ideal Gas Law: PV = nRT, where P = pressure, v = volume, n = number of moles (think of this as quantity), R = gas constant, T = temp. So if you reduce temp, and the pressure is relatively constant, the volume is lower. In simple terms, the lower volume means higher density air which equals more oxygen to burn the fuel.
IC lowers egts by burning more fuel via cooler denser air charge going in. More oxygen means more diesel burnt. I wouldnt see an IC being a draw back, but there are situations where they are more beneficial than others. The only reason i dont have one yet is the lack of room.