Looking to get a bigger intercooler and researched but cannot find a specific answer to my question

will a 3" inlet/outlet intercooler reduce the cooling efficiency if connected to the 2.5" piping on the inlet and outlet?

no point in going 3" piping all the way around as it does not increase power

 

Nothing to do with cooling efficiency. Try to get silicone transitions that are gradual if you can, but if not I would not sweat the standard abrupt transitions. If you can get the Garrett 24x12x3.5 core they work exceptionally well.

 

I was thinking about getting the 4” core from ets but then saw the 3.8” garrett core from nisei I saw used online

i did more research on it but cannot find the answer I want based on the flow, temp, and hp comparison

 

What is the specific question?