109 e3b against spitfire II

[Crumpp]

if you are comparing identical intake conditions.

Any fuel metering system that introduces fuel into the intake system cuts down on the efficiency of that intake just by being there.

Sure the fuel cools the charge but the airflow volume is restricted by the fuel metering device. Carburetors, whether float, SU, or TBI restrict the airflow volume.

With Direct Injection, the intake can be designed free from the volume and flow obstruction of a fuel metering system component.