hello physics experts! i have a simple question about PSI and CFM and would like your input. context of the question: a car's turbocharger is essentially an air compressor that forces positive "boost" into the intake manifold. now a great debate among car enthusiasts is why a small turbocharger will produce less power than a big turbocharger at the same psi, same car. 2 answers that are often given: turbocharger efficiency (more efficient = cooler and denser charge) and different CFMs per turbo under the same psi. the underlined section is the topic in question. question: If a car's turbocharger is set for 19psi, isn't there a corresponding CFM associated with 19psi? Isn't the pressure that the manifold sees (in this case, 19psi), directly related to how much airflow (measured in cfm) the manifold is getting hit with? How can the same car, same conditions, experience 19psi by 2 different flow rates? 2 different levels of cfm cannot achieve the same level of pressure (psi) in the intake manifold, correct? Some people are arguing that different turbos, although set to the same psi, will produce different CFM. If the flow rate is different, then I don't see how the manifold can experience 19psi under both conditions. Need some clarification here by some physics gurus .