When tuners began to get their hands on the GT and started placing them on the dyno, a shortcoming of the stock design was noticed. The pliable rubber air inlet boot would collapse at higher rpms and limit the amount of air the GT could ingest. There would be a corresponding drop in HP as the engine fought for more air. The situation can occur on stock GTs - especially when the boot becomes warm and more pliable from surrounding engine heat. On modified GTs with exhaust, supercharger, or other mods, the air inlet stiffener is a must. Installation is straightforward. Simply remove your rubber inlet boot and then work this stiffener inside. Repeated dyno testing has proven that the stiffener will not impede airflow, and it absolutely prevents the collapse of the stock inlet boot.