2G intake air temp

[Proud Owner]

hey guys, I logged a run yesterday and noticed something odd (I thought). I never looked at my intake air temps before but I added that to the log and I was expecting to see the temps go up as I made boost but for some reason they go down! I think what's happening is my air filter is right off the side of my turbo under my hood and practically on top of my exhaust manifold so I'm thinking when the car is not under load, its not sucking in alot of air and getting hot under hood air. then when you hit boost its sucking air in so fast its getting "fresher" air that's not as hot as the stagnant under hood air so it's cooler to begin with. also its rushing through the hot metal charge pipes faster so it doesnt pick up as much heat there. I do have a HUGE FMIC which im sure helps a lot.
it was about 80f outside, the IAT when slowly idling down a hill was climbing up to 108f. then I gave it gas and went up to 13psi the temps went down to 92f.
not a huge change, just not what I was expecting to see.
does this sound right?

 

[pauleyman]

Iat are pre turbo. Yes you are likely correct. Charge pipes do not mean anything to this discusion.

 

[Proud Owner]

I guess I'm on the noobie page for a reason sorry. I thought IAT was supposed to measure the actual temp of the air coming into your engine. mine is mounted after the turbo, right before the throttle body. is that wrong? or do I not understand what the IAT sensor is for?

 

[pauleyman]

Do you have a separate iat sensor (non oem)?

 

[pauleyman]

If you're running ecmlijk speed density or someting other than stock mas this changes the discussion.

 

[Proud Owner]

sorry, guess more info on the car would be helpful. ALL sensors, ignition, timing etc. are all run off HALTECH ecu. nothing is stock. no MAF, just MAP. I originally thought my question was more of a general question which is why I left my specifics out. it was simply, do you sometimes see IAT's drop under boost because of the high volume of airflow. I was simply surprised to see it drop instead of go up.
that is all.

 

[pauleyman]

With a big fmic I would think so as you have also increased air across the core.

 

[craig4g63]

sorry, guess more info on the car would be helpful. ALL sensors, ignition, timing etc. are all run off HALTECH ecu. nothing is stock. no MAF, just MAP. I originally thought my question was more of a general question which is why I left my specifics out. it was simply, do you sometimes see IAT's drop under boost because of the high volume of airflow. I was simply surprised to see it drop instead of go up.
that is all.

I suggest testing the IAT sensor for proper operation. Remove and provide an external heat source. If its a thermistor, the resistance should decrease as the temp increases.