Actually more of an observation. I noticed that the hose running air from the intercooler to the intake is about an inch smaller than the output from the intercooler and the input of the intake. In other words, the hose is strecthed to fit over the connection ends of the intercooler and the intake, but is smaller in between the two. That has to make a difference in the amount of air it takes in. Would that inch make a noticeable performance difference?

 

It may be the fittings that you are noticing. In fact the overall inside diameter is the same.

 

Imolas is right ...also when talking about flow try to remmeber that basicaly the flow is limited to the smallest part, meaning you can have a 5 inch hose there but you throtle body is still the smallest part so there would be no difference in actual flow the air would just slow down in the larger tube then speed up through the throtle body