This is a pretty easy installation for the home mechanic. The undersized factory turbo inlet creates a pressure drop in the flow of intake air supply that feeds the turbo. When the intake air at this low pressure is compressed by the turbo the intake air becomes super heated. The intake air enters the intercooler which absorbs some of the heat and then passes this heat to the radiator that is positioned directly behind the intercooler. The cooling efficiency of the radiator is reduced by the hotter than necessary airflow passing from the intercooler and through to the radiator. Since the intake air is as hot as it is the combustion temperature is higher than necessary.