I have a Boosted B16 running on a S300, RC engineering saturated 550's 2.25 charge piping and a 24x6x3 IC. I'm pushing about 10-11.5psi right now. I was data logging on a trip to the tuner who is about 1.5 hours away from me and noticed that my coolant and Intake temps were slowly rising as I was driving at a steady 70mph. On short trips to the store, driving to work etc. Everything seems fine but if I take a trip longer than 30 minutes it seems to slowly "heatsoak" by 2 degrees ever few minutes or so. We addressed the coolant temps as much as we could but it seems as if the intake temps are high for some reason either way and maybe in turn effecting the coolant temp too. There are no apparent airflow blockages that I can think of. The tuner said it might be because my I.C. and piping is too small for my application and wants me to try at least a larger IC to see if it will help. Have any of you had this problem? And if so, what caused it and how did you fix it? Thanks for your time!

 

as the engine heats up, the intake heats up as well. a hot intake manifold and hot pressureized air entering the engine just creates more heat. if your intercooler isnt efficient enough then it cant cool the air charge enough. boost creates more cylinder pressure which creates more heat so if your radiator is not large enough then this will also cause the intake temps to rise.