Oh, I should state I was not ragging on mods. And, sometimes, they DO reduce fuel economy. But, I was only suggesting that as a possibility, not trying to be critical of you for installing them.
The article I remember most clearly said to think of the engine as an air pump. Compressors and other types of air moving devices have specific CFM ratings. Using bigger hoses before and after the pump will not necessarily result in more throughput.