# IAT Relocating



## RJ_05GTO (Jul 6, 2008)

I know we have talked about IAT relocating a lot but after my last trip to the track and the heatsoak issues with the stock IAT sensor in the MAF. I decided to pull out my vectors breakout harness that I took off the car when I installed my K&N intake and plugged it in and I dropped the IAT sensor down behind the bumper in front of the fenderwell and wire tied it into place. Its almost out of the engine bay altogether. And no matter what conditions I tried even sitting still the IATs stayed a few degrees above ambient without climbing at all that i noticed when normally it would have soared to 120 degrees or more. 
I mean what is better? Letting the computer read the heatsoaked sensor or letting it see the actual ambient air temps that I hope is closer to the actual air temperature that the engine is sucking in?


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## PBF Bioset (Apr 25, 2010)

I don't really know, what this IAT is, but if it is bought by promissing more hp the difference of tempretures is easy to explain...
For the case I understand the funktion right it scales the tempreture of inflowing air. If the engine thinks, that the air is hotter ( more volume; less O2/volume) ... the lambdasensor registers that after ignition to much o2 is left, so he gives advise to built the mixture richer...

In fact this doesn't make any difference. The engine would react a bit faster maybe. 

If I'm wrong please explain the funktion of this part. Thank you.


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## RJ_05GTO (Jul 6, 2008)

PBF Bioset said:


> I don't really know, what this IAT is, but if it is bought by promissing more hp the difference of tempretures is easy to explain...
> For the case I understand the funktion right it scales the tempreture of inflowing air. If the engine thinks, that the air is hotter ( more volume; less O2/volume) ... the lambdasensor registers that after ignition to much o2 is left, so he gives advise to built the mixture richer...
> 
> In fact this doesn't make any difference. The engine would react a bit faster maybe.
> ...


IAT= Intake air temperature sensor. The stock IAT is integrated into the mass air flow sensor. The mass air flow sensor housing and the intake tube all heat up with the underhood temperatures and hold the heat which makes the stock IAT sensor read the underhood temperatures rather than the actual air temperature that is flowing through the intake which in turn makes the computer pull unnecessary timing which reduces horsepower and performance. 
I think locating the IAT sensor away from engine heat will give the computer a more accurate reading of actual intake air temperature while cruising when the engine is getting more fresh cooler air but sitting still at idle the actual temp of the air and what the IAT sensor is reading will probably be off due to the stagnant air under the hood. I was just wondering what other peoples thoughts were.


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## Gunslinger (Jan 5, 2010)

I've heard you want it to read an air temp that is at least within the vicinity of the intake so it can accurately do its job. Ive seen alot of people just move it off near the fender well so it still read underhood temp but not such a superheated one as it would normally get in its stock location. I was thinking of doing this IAT relocate myself before summer get here and it gets to be 120 outside..Heatsoak is a notorious issue with 04 05 05 GTOs. Does the move really help with this or does it really matter?


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## RJ_05GTO (Jul 6, 2008)

Gunslinger said:


> I've heard you want it to read an air temp that is at least within the vicinity of the intake so it can accurately do its job. Ive seen alot of people just move it off near the fender well so it still read underhood temp but not such a superheated one as it would normally get in its stock location. I was thinking of doing this IAT relocate myself before summer get here and it gets to be 120 outside..Heatsoak is a notorious issue with 04 05 05 GTOs. Does the move really help with this or does it really matter?


Yes if you can keep the intake temps down it really does help. But you also want the IAT reading to be as close to the actual air temperature that is going into the engine as possible. From the stock sensor reading I know the actual air that is going into the engine at cruising speed on a 90 degree day is not 120+ degrees and that is a typical reading on a 90 degree day that i notice. Thats why im trying to find a good place to take the temp readings from that will give the computer a more realistic reading. I drove around today with it relocated and my intake temps at the highest was 100 degrees after i turned the car off and let it sit. It was running like 86-90 degrees cruising which was pretty close to the outside temperature and before the relocation it would have probably been well over 100 degrees at the lowest when cruising. I believe it starts pulling timing at 86 degrees like -3 degrees and as the temperature rises it pulls more and more like up to -9 degrees. I didnt see any Knock Retard on my Dashawk. And the car felt strong like it should.


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## PBF Bioset (Apr 25, 2010)

RJ_05GTO said:


> IAT= Intake air temperature sensor. The stock IAT is integrated into the mass air flow sensor. The mass air flow sensor housing and the intake tube all heat up with the underhood temperatures and hold the heat which makes the stock IAT sensor read the underhood temperatures rather than the actual air temperature that is flowing through the intake which in turn makes the computer pull unnecessary timing which reduces horsepower and performance.
> I think locating the IAT sensor away from engine heat will give the computer a more accurate reading of actual intake air temperature while cruising when the engine is getting more fresh cooler air but sitting still at idle the actual temp of the air and what the IAT sensor is reading will probably be off due to the stagnant air under the hood. I was just wondering what other peoples thoughts were.


Thanks a lot. 
Although I think it doesn't really change anything if you determinate that range of difference this might help:

Thermistor - Wikipedia, the free encyclopedia

Maybe you install a thermistor somewhere it will get true temperatures. It should be soldered in series to the stock sensorwire. To get an idea of the resistance that should be choosed I found this:

http://numericalmethods.eng.usf.edu/mcd/ele/05inp/mcd_ele_inp_phy_problem.pdf


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## Rukee (Feb 8, 2007)

PBF Bioset said:


> Thanks a lot.
> Although I think it doesn't really change anything if you determinate that range of difference this might help:
> 
> Thermistor - Wikipedia, the free encyclopedia
> ...


Why would you solder a new temp sensor in when that's what the IAT sensor is??
Just relocate the exsiting one.


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## PBF Bioset (Apr 25, 2010)

Rukee said:


> Why would you solder a new temp sensor in when that's what the IAT sensor is??
> Just relocate the exsiting one.


Not a new one. I thought of an additional one that will balance the difference from real to scaled tempreture. I read a few threads and it seems to be, that every stock sensor has a different range of measurement error. So I came to the conclusion, that everyone would need a special for the car calculated one. The thermistors cost maybe 1$ and are easier to relocate.
Then everyone can easily try, where the best place for install is. That was the idea so far^^

Or just relocate the hole thing. You're right :cheers


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## GM4life (Mar 18, 2007)

Folks have replaced the stock thremister with a aftermarket one that is more responsive than the factory one. The point of relocating the IAT is to get it away from the heat of the radiator. Heat radiating on the IAT gives it a "false" reading when the IAT is heat soaked.


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## PBF Bioset (Apr 25, 2010)

Ok. I viewed some fotos. It's directly in front of the radiator, isn't it? 
Would a heatshield cut off a piece of sheet and well bend solve this problem? 
Doesn't a GTO have an ... aehm...position 1 :
Lufterzarge BMW 3' E30, 318is (M42) ? BMW Teilekatalog

Looks like this^^
http://mickscar.dyndns.org/ebay/artikelbilder/103440.jpg


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