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IAT temps...
whats the difference between iat and iat2 and how close should they be together? cruising around at 50mph with it being around 80 outside iat and iat2 both read 81. after a pull iat2 rose about 20 degrees higher than iat, 81 vs 102 at 6200. once i let off then iat rose up to 91 then slower tapered back down to 81 after some driving. iat2 took longer to get back to 81.
noticed this after a log and just wondering where each of the sensors are and how they should compare to each other.
the part in the log im talking about is the second pull i did.
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Closer iat2 is to iat the higher the efficiency of your intercooler
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The iat sensor is pre turbo (part of the maf sensor), iat2 is post intercooler (tmap sensor in charge pipe)
It's totally normal to see higher iat2's than iat's at wot obviously due to the fact that compressed air from a turbo generates heat. Depending on the efficiency of you intercooler and your turbo at a given pressure level will determine how much higher your iat2 are from you iat's.
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I have relocated my MAF to the charge pipe, so both sensors will be seeing the same temperature in theory... I am curious if the computer needs to see a difference. I dont see why it is a problem at all just a curiousity.... any ideas?
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the computer can use the variation between the two to control kr. we dont have iat air vs kr tables so its pre-programmed at the time.
what i really think is going on is the temp sensor at the maf iat1 is used to help gather density data at the point of which the maf is reading its airflow data.
see if its before the turbo the air is denser and colder meaning more is coming in but in a relocate it will be in a hotter area meaning not as dense air, so less is comming in at that point. the changes are minor but by tagging that sensor with the maf sensor keeps it easy to cover the minor factor changes.
iat2 can be used for watching the ic efficiency and if in the factory maf location the iat2 is downstream and can be used as a density after turbo correction factor. the density as stated will be thinner at the manifold than at the factory maf location which can change the flow characteristics just slightly.
those are just my opinion though.
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so, iat=maf and iat2=map?
i guess 20 degrees isnt too bad for a stock intercooler and pipes.
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iat= maf
iat2= lower charge pipe sensor
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It's not great, but it's relatively normal. At the end of a long 3rd to 4th gear pull I'll usually see somewhere between 8-11* higher iat2's than iat1 with my zzp ic. My stocker I was seeing somewhere between 12-15* above my iat1 temps. Not a huge difference but enough to notice in a log.
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lower charge pipe sensor=map sensor right? thats one of the two sensors you change when converting to 3bar.
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i guess the sky runs a little hotter stock than the cobalt.
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map sensor = map sensor
lower charge pipe sensor= boost lo res=iat2
maf sensor= iat
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does the cobalt have two separate sensors in the cold charge pipe? the sky/solstice only has one sensor in the cold side charge pipe and in my case its the 3bar sensor now, the other 3bar sensor is in the intake manifold.
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The cobalt is setup the same way (low res tmap sensor=coldside pipe, map sensor=intake mani). The only time there are 2 sensors in the coldside charge pipe is if the maf is relocated there.
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notice the 3 bars have a 4 wire connector that only the charge pipe uses all 4 of.....position #3 is left blank on the manifold because it is a temperature signal output which is used only in the lower charge pipe.
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i see what youre saying now.
iat=maf
iat=cold side charge pipe=one of the two map sensors, not the mani one.
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