types of IAT's
 

so looking into IAT's for my twin turbo build and seems there is two types - open and closed , two wire and three wire

which do I need to run properly and for tuning ?
thanks
Ken

I think this pertains to the particular PCM and its built
in (or tune-table) calibration curve, ohms vs temp. I
have never seen a 3-wire IAT myself.

If you need the IAT to respond quickly to inlet air temp
then you want an IAT sensor with as low a thermal
mass as possible and as little shrouding by its mechanical
enclosure as possible. Stock 4th gen F-body, the IAT is
chubby and set down in a big plastic shell with airflow
partially blocked. But you can find termistors with the
same R-temp curve that are much tinier, and bare.
The thing to worry about is, what happens to such
a component when suspended in a high flow but variable
air stream - how long before the resistor nugget ends
up fatiguing the leads that suspend it, and it heads for
daylight the hard way?

maybe I should be asking the question another way
I am wanting to be strictly Speed Density for tuning purposes and so need to install an IAt in the air stream as the MAF took care of that before
so the appropriate question might be - what are you speed density guys using for an IAT and do you have a part number

thanks

Ken

What kind of car is this on an Fbody a lot of air boxes have a space to put an IAT sensor in. You could just use a stock Fbody sensor

its a chopped 48 Mercury car - so everything will be custom built - and no air boxes lol
so most likely it ill be mounted in the inlet pipe 6" or so from the throttle body unless someone tells me to do it better/different

what are you using for a pcm if it's a factory pcm you could still use a stock Fbody sensor like you want and it should work pretty well

do you have a part number please - I don't know what an F body is lol
and yes to factory 03 pcm

https://ls1tech.com/forums/forced-induction/743423-threaded-ls1-iat-sensor-part.html

It's a common and cheap part. Plug and play.
Although not a bad idea to check accuracy with ice and boiling water and recalibrate the PCM if you want perfect results.

I have my IAT mounted behind a head light so that it reads as close to ambient air is possible. Otherwise I was getting terrible heat soak (40F+) from idling in the staging area of the drag strip; resulting in a very lean AFR at the beginning of the run.

Stock cars are engineering to minimize heat soak on the IAT, but that can be difficult to duplicate in a swap. For example, in a C5 Vette (as documented by RonSSNova), the IAT sits in front of the radiator and Ron was only experiencing 10F of heat soak at the drag strip.

In my case, if the air going through the intake system gets heated more than ambient temperature, my engine will run a bitter richer than intended, which is better than the other way around.