20. Graph 2: Whipple Supercharged Modern Mouse-7.4 psi vs. 9.2 psi One of the great things about running almost any type of forced induction is the ability to dial up additional power by increasing the boost pressure. Swapping out the 3.875-inch blower pulley for a smaller 3.625-inch pulley increased the boost pressure by nearly two psi. When combined with a set of larger 1-7/8-inch headers, the pulley swap pushed the power output over 800 hp to a maximum of 804 hp at 9.2 psi. Despite the conservative boost levels, the Whipple had improved the power output of Modern Mouse by 263 hp and 164 lb-ft of torque.