High IAT= lean AFR

[LSxpwrdZ]

My IAT sensor is temporarily stuck under my windshield wiper... I put a vic jr and accufab 4150 TB on and it's done great so far. I just went and picked up the faster response sensor that Soundengineer posted in another thread and I'm gonna try to thread it into the manifold and see what that does but I'll probably end up extending the wiring and putting it down in my sheetmetal scoop in front of the radiator.

[JimMueller]

I recently received all the parts to relocate mine. Anyone have any negative aspects to relocating the IAT? Do I need to shield it somehow to protect it from dust, debris, etc?

[kamikazematt]

ls, do u have a link to that thread or a part number for that sensor?

[Google]

ls, do u have a link to that thread or a part number for that sensor?

gm part number 12160244

[Frost]

gm part number 12160244

That's the OEM part. The threaded fast-acting sensor is 25036751

[S2H]

That's the OEM part. The threaded fast-acting sensor is 25036751

that part also requires that you skew the IAT temperature table some...
I found it to be about 15% different... just multiply your IAT table by .85...gets it very close.. I havent played with it enough to get the exact values for the entire table, but like I said.. .85 gets you in the ballpark

[jimmyblue]

I have a thermistor I got from Digi-Key (forget the P/N,
but it's something that was posted either here or on
LS1Tech with the same cal curve) and it's up under the
plastic cowl trim near the PCM but outside the engine
bay.

It behaves -way- better than stock location or in the
85mm MAF. The only time it gets hotter than ambient
is in direct sun (Florida). And it's still way better than
underhood.

[speedyss]

Potentiometer+Zero'ed out bias charge= Total control
Been running it like this for years with great success.

[Atomic]

Recently I had a procharged car that was 2bar SD. It made 764rwhp at about 16psi. Stock cubes forged, AFR 205s, 9.8-ish:1 SCR and the cam was something like 235/237 on a 113LSA. He has a small second fan and it blows near the IAT. Hot starts were MISERABLE. I spent literally about 8 hours on things to improve startup and fueling. In stop and go traffic, heat soak was horrible too. On a 98 deg day it would read 155degF after sitting about 7-8 mins. With his IAT AFTER his two methanol nozzles, we really want (need) to see charge temp under boost. I finally gave up fighting it. I used his hobbs switch (1-2psi) that triggers the second Walbro to run another relay. This relay switches the IAT from the unit behind and under his driver's front headlight whenever there is boost to the IAT sensor in the charge pipe near the throttle body and after the meth nozzles. The car runs and drives immeasurably better!! With no wandering IATs, the VE took all of a few minds to get nailed. Sounds crazy to use two IATs and switch, but it worked very very well.

I say front bumper but usually end up behind the headlight, somewhere that it can see outside airflow.

I can get him to take a pic and send it to my phone.

-edit-
It seems that N/A SD cars are more sensitive to this the higher their DCR as well, as I previously mentioned. You will see it in MAF cars to some extent with high DCRs or really large cams in general even if it only manifests in goofy hot starting. IAT relocation works well for those cars also.

I am glad I found this. I have been struggling with hot restarts because I have a holley hiram with the back drilled and taped for the iat sensor. After sitting for a while IATs will often be 140-150 which makes the idle very lean (have to use the meth test button to get it to idle at all!). I still want to see the air temp in the intake under boost, but this lean startup issue sucks.