I decided i want to check and see how my IC is doing before I drop some loot on a better one.
I assume the easiest way off the top of my head is to log the IAT's in Evoscan.

I see two options though that can possibly do this?
Air Temp and MAF Air temp scaled.

which would I use?

Also do I need the external unit to log this or is there a sensor in the stock IM to log this to give me an idea if my car is heat soaking horribly?
from what I understand this gets read in the MAF on a stock setup?

 

Nither. Regular logging with evoscan only reads the temps at the maf sensor (preturbo), so you will not be able to see if an IC upgrade makes a change.
As far as I know, to see if a change in IC's you will need another sensor in the piping after the IC or in the IT manifold.
I'm not sure if switching to speed desity includes the capability to to this either.