See if someone may stumble on a eureka moment that Im missing. 5th Gen SS M6, cam longtubes and procharger. Didnt realize at first how small of a pulley customer had on D1SC boost would peak around 4800 and then fall which wasnt right. Put a very heavy spring in bypass valve to make sure that was staying shut, no change. Did the math and realized the 3.55/7.65 pulley combo at 7K would be near maxing this blower out and should make 15psi+, not the 8 and then fall down we are seeing.