IAT Sensor Mounted In Plenum. OK?

Paul Smith · Post by **Paul Smith** » Mon May 29, 2006 12:15 am

I intend to mount my IAT sensor in my plenum. The throttle body is at one end of the plenum and the IAT will go at the opposite end. The car is turbo'd. Will this be ok?

davezed · Post by **davezed** » Mon May 29, 2006 1:03 am

Hi Paul
I think I read somewhere on this site that implied it might not be so good at the minute, Sensor will probably suffer heat soak. I think later versions of MS2 are going to address this issue. What you might find at the moment is you would probably lean too far out as your engine warms up.

Cheers
DaveZZ

Bernard Fife · Post by **Bernard Fife** » Mon May 29, 2006 2:19 am

I intend to mount my IAT sensor in my plenum.

Paul Smith,

Yes, that should be okay. The IAT sensor doesn't have to be close to the throttle body (it does have to be 'downstream' of the compressor and intercooler, which yours is).

Lance.

davezed · Post by **davezed** » Mon May 29, 2006 3:28 am

Hi Lance
Does this mean I am mistaken, having a IAT in an inlet manifold is ok? I was looking at doing this on a Victor Junior style manifold but thought I read something about heat soak being an issue (this is why people are placing them in the air box I think I read)? Sorry Paul, Lance would have a much better idea than me.

Cheers
DaveZZ

Bernard Fife · Post by **Bernard Fife** » Mon May 29, 2006 3:35 am

DaveZZ,

I think it depends an awful lot on the specifics of the manifold and IAT mounting. Some people have a problem, many do not.

I would be most concerned about potential heat soak issues if you are using a 'closed element' IAT sensor (instead of the recommended open elemnet types for boosted engines), if the exhaust or coolant is near the intake manifold, the intake air is particularly hot or cold (I.e., a centrifically supercharged engine with no intercooler but with a cold air intake might see a large and rapid change in intake air temps that could be an issue), etc.

However, in general, there's no reason not to use the intake, until experience proves it is a problem.

Lance.

Paul Smith · Post by **Paul Smith** » Mon May 29, 2006 8:34 am

Thanks for the replys guys.

Jedrik · Post by **Jedrik** » Mon May 29, 2006 10:43 am

On a turbo engine definately dont put it in the air box!

You may be better to get it more into the airstream. It seems to be a low airflow (idle) issue with hot engine so that stagnant air is telling the computer the air getting to the cylinders is less dence than it actualy is.

My IAT is midway on the plennum and when I sunk the probe 1/4 inch deeper by cutting the pipe threads deeper it made a noticable improvement in the hot idle mixtures.
... though closed loop ego idle has been even more effective.