Just make/relocate a new IAT sensor
02-17-2011, 10:37 PM
#1
Launching!
Thread Starter
iTrader: (2)
Join Date: Mar 2009
Location: Central NY State
Posts: 257
Likes: 0
Received 0 Likes
on
0 Posts
Just make/relocate a new IAT sensor There has been some talk in other threads about inherent problems with the LS4 IAT sensor. It reads hot air present in the MAF caused by location and being close to exhaust and hot air coming back out the throttle body from the engine. It is also pretty slow to react to air temp changes. I made a new IAT that reacts much quicker and relocated at the far front end of the cone filter in my homemade aluminum CAI box. This is pretty easy if you have any soldering skills at all or at least know someone that does. The thermistor in our IAT is slow, you need a faster reacting one and a convienent fixture to hold it. Get a Omega 44005 thermistor (http://www.omega.com/ppt/pptsc.asp?r...NTS&Nav=temd11) scroll down page to find it.
Get a GP Sorensen # 779-19036 IAT from a parts store, I think its a '98 Camaro piece. You will need to replace the thermistor in the Sorensen IAT with the Omega part. Just pull hard but careful on the electrical connector pins in the IAT and the insides will come out intact. Its just basically the connector with 2 pins to which the thermistor is soldered. Carefully cut off the original thermistor at the very end of the pins and solder on the new Omega thermistor. These are small fine wires, so be careful, use a heat sink. When done, push it all back into the plastic Sorensen IAT body.
Get a IAT relocation cable from one of the W Body performance sites or just make a cable yourself with the correct ends. I just drilled a hole in the end of my cone filter which is inside my aluminum air box, I put the new IAT in the hole and connected it with the relocation cable to original IAT cable.
If you look at the picture, you can see the relocation/extention cable entering my cold air box through a rubber grommet at the right rear of the box.
Get a GP Sorensen # 779-19036 IAT from a parts store, I think its a '98 Camaro piece. You will need to replace the thermistor in the Sorensen IAT with the Omega part. Just pull hard but careful on the electrical connector pins in the IAT and the insides will come out intact. Its just basically the connector with 2 pins to which the thermistor is soldered. Carefully cut off the original thermistor at the very end of the pins and solder on the new Omega thermistor. These are small fine wires, so be careful, use a heat sink. When done, push it all back into the plastic Sorensen IAT body.
Get a IAT relocation cable from one of the W Body performance sites or just make a cable yourself with the correct ends. I just drilled a hole in the end of my cone filter which is inside my aluminum air box, I put the new IAT in the hole and connected it with the relocation cable to original IAT cable.
If you look at the picture, you can see the relocation/extention cable entering my cold air box through a rubber grommet at the right rear of the box.
02-18-2011, 10:16 PM
#3
Launching!
Thread Starter
iTrader: (2)
Join Date: Mar 2009
Location: Central NY State
Posts: 257
Likes: 0
Received 0 Likes
on
0 Posts
I used my own specs. Basically I measured several times, made a template for trial fitting from matte board and cardboard. Lots of trial fitting. This is not the first CAI box I have made though. I made one for my 2001 Monte SS with the 3.8L and my 05 Grand Prix GTP.
I also looked at a lot of photos of commerically available units. I just like to do it myself and save hundreds of $$$$. Standard aluminum sheet and plexiglass. I also insulated the interior of the box for heat and sound. Use caution though. This box rubbed against an air conditioning tube sensor cable and broke a wire. Cost me $$ to find out why my air conditioning wouldn't work!
I also looked at a lot of photos of commerically available units. I just like to do it myself and save hundreds of $$$$. Standard aluminum sheet and plexiglass. I also insulated the interior of the box for heat and sound. Use caution though. This box rubbed against an air conditioning tube sensor cable and broke a wire. Cost me $$ to find out why my air conditioning wouldn't work!
02-19-2011, 08:19 AM
#5
TECH Apprentice
iTrader: (3)
Join Date: Mar 2005
Location: Mchenry, IL
Posts: 349
Likes: 0
Received 0 Likes
on
0 Posts
i know there are probably a lot of people looking at this saying what is a thermistor, or i dont know how to properly solder small wire like that. Something you may want to consider, though a little time consuming is to build some and off them up for sale. granted it would take sourcing IAT housings, but im sure there are a lot more people willing to buy the item than do it them selves.
02-19-2011, 08:48 AM
#6
Not to create problems or anything like that.. your efforts are commendable but..
by moveing the IAT out into cooler air you are actually decreasing your performance. The whole principal behind the IAT is to give an accurate temp to the air as it enters the combustion chamber, combined with an accurate fuel measure to keep your A/F ratio as close to 14.7-1. Even though you move the thermistor to a cooler position ,the air in the induction system is still being heated as it passes through the system and this would require less fuel for the less dense air and also less timing to produce optimal performance. Instead by moving the IAT out into cooler temps the engine management would in fact be adding more fuel than is really required. Now if there was a way to actually lower the actual temp of the combustion air prior to entrance to the combustion chamber we could actually benifit by such a mod.
by moveing the IAT out into cooler air you are actually decreasing your performance. The whole principal behind the IAT is to give an accurate temp to the air as it enters the combustion chamber, combined with an accurate fuel measure to keep your A/F ratio as close to 14.7-1. Even though you move the thermistor to a cooler position ,the air in the induction system is still being heated as it passes through the system and this would require less fuel for the less dense air and also less timing to produce optimal performance. Instead by moving the IAT out into cooler temps the engine management would in fact be adding more fuel than is really required. Now if there was a way to actually lower the actual temp of the combustion air prior to entrance to the combustion chamber we could actually benifit by such a mod.
02-19-2011, 10:56 AM
#7
12 Second Club
iTrader: (14)
Join Date: Jun 2007
Location: Renton, WA
Posts: 2,563
Likes: 0
Received 0 Likes
on
0 Posts
Not to create problems or anything like that.. your efforts are commendable but..
by moveing the IAT out into cooler air you are actually decreasing your performance. The whole principal behind the IAT is to give an accurate temp to the air as it enters the combustion chamber, combined with an accurate fuel measure to keep your A/F ratio as close to 14.7-1. Even though you move the thermistor to a cooler position ,the air in the induction system is still being heated as it passes through the system and this would require less fuel for the less dense air and also less timing to produce optimal performance. Instead by moving the IAT out into cooler temps the engine management would in fact be adding more fuel than is really required. Now if there was a way to actually lower the actual temp of the combustion air prior to entrance to the combustion chamber we could actually benifit by such a mod.
by moveing the IAT out into cooler air you are actually decreasing your performance. The whole principal behind the IAT is to give an accurate temp to the air as it enters the combustion chamber, combined with an accurate fuel measure to keep your A/F ratio as close to 14.7-1. Even though you move the thermistor to a cooler position ,the air in the induction system is still being heated as it passes through the system and this would require less fuel for the less dense air and also less timing to produce optimal performance. Instead by moving the IAT out into cooler temps the engine management would in fact be adding more fuel than is really required. Now if there was a way to actually lower the actual temp of the combustion air prior to entrance to the combustion chamber we could actually benifit by such a mod.
My only problem with the sensor is that it reads very slowly.. There is probably a reason for this though..
Trending Topics
02-19-2011, 11:18 AM
#8
TECH Enthusiast
iTrader: (3)
Join Date: Aug 2007
Location: Ottawa IL
Posts: 749
Likes: 0
Received 0 Likes
on
0 Posts
The stock IAT sensor in the MAF gets heat soaked and stays hot. It reports the temp of the MAF not the intake air temp. I used the MSD IAT sensor (I think it uses the omega thermister?) mounted in a TB spacer. Works really well and heat soak is not a problem. Last summer I went from a pegged IAT (its like 150* or 199* I don’t recall) to a few deg over ambient in a matter of seconds by driving down the road.
