Recently I performed some intake temperature tests. They are not dead acurate but are atleast an indication of when heat soak is affecting your engine. I used some digital thremometers from jaycar for the tests.
The car: 1993 R33 GTSt, 3" turbo back exhaust, 8psi (stock) boost, stock intercooler, pod filter with cold air partition (95deg neoprene heat shield).
Ambient temperature: 17degC
1st Test: Cruising at 110km/h
Pod = 15deg
AFM = 15deg
Engine Bay = 35deg
2nd Test: Stuck in traffic (45km/h max.) (heat soak had set in)
Pod = 35deg
AFM = 37deg
Engine Bay = 55deg
3rd Test: On boost hill climb and high speeds
Pod = 14deg
AFM = 12deg
Engine Bay = 33deg
4th Test: Heat Soak
After pulling up at a set of lights from cruising at 110km/h, it took 3 minutes to reach full heat soak as shown in the 2nd test. It took 7 minutes of driving at 110km/h again to fully get rid of it.....
5th Test: After idle for 3 mins
Pod = 40deg
AFM = 43deg
Engine Bay = 60deg