Although the first installment of the supercharged 3.8-liter V6 in a Pontiac Grand Prix GTP didn’t occur until 1997 to kick off the Gen-VII Grand Prix, the engine had been used in the Pontiac Bonneville for several years. An article from the pages of the October 1997 Hot Rod magazine, shared online by MotorTrend, reports the first supercharged 3.8-liter Grand Prix GTP had 240 horsepower at 5,200 rpm and 280 lb-ft of torque at 4,400 rpm. For comparison, the naturally aspirated 3.8-liter in a 1997 Camaro RS made 200 horsepower and 225 lb-ft of torque.
The Grand Prix GTP’s Eaton supercharger played a significant role in providing the additional horsepower and torque. A naturally aspirated engine relies on vacuum to pull the mixture of fuel and air into the combustion chamber. However, a supercharger’s forced air induction provides positive pressure, 7 psi in the 3.8-liter’s case, eliminating the reliance on vacuum.
