[randycat99]

Now that the cold weather has rolled in, and for those of you who have scanners to monitor your IAT, do you ever wonder if there is cold weather extremes where the resultant IAT value become counterproductive? I just did a big trip through the southwest going through Flagstaff in the middle of the night, and I was pulling in 28 deg F air at the IAT.

You guys ever see such extremes going right into your engine?

EDIT: I spoke too quickly- what I should have said is that the ambient temp was reading 28, and I was pulling in some chilly 30-ish deg air at the IAT.

 

[Harpslinger]

Only detrimental effect of cold air I've ever seen is freezing up carburetors and fuel lines. I have heard of the cold freezing and cracking rotating assembly parts, but that was extremes, far far north of where its considered sane to live.

 

[rayzazoo]

Interesting thread. It would be beneficial to know the ideal intake temperature the hemi prefers.

 

[randycat99]

That is actually a question I wanted to run by the SRT Engineers some time ago, but I couldn't figure a way to word it in a constructive and thought provoking manner. My worry was that the SRT Engineers would just say the stock system just happens to do the trick with sheer heatsoak oblivion temperatures at the IAT, after which we would all be left with scratching heads, and a wasted question opportunity.

 

[KnuckleBuster]

Only detrimental effect of cold air I've ever seen is freezing up carburetors and fuel lines. I have heard of the cold freezing and cracking rotating assembly parts, but that was extremes, far far north of where its considered sane to live.

You mean like here? :alf:

 

[Retired LE]

What's IAT?

 

[mullerjd]

I don't see where it would be so cold as to really have a detrimental effect. The National Science Foundation uses all kinds of vehicles around Antarctica and the south pole with no issues. South pole summer temps are normally in the -40 range, winter closer to -100.

 

[The Dude]

Does IAT stand for Intake Air Temperature?

 

[fishmannaknp]

I have driven my 09 R/T Classic in temps of minus 40 degrees F with absolutely no problems at all....Just sayin

 

[boyohboy]

Too Cold?

I have driven my 09 R/T Classic in temps of minus 40 degrees F with absolutely no problems at all....Just sayin

I believe that the normally aspirated engines of our time have evolved to operate at extremes. Cold air is a blessing and a curse. Reading the info in AllPar.com the info points out that the Hemi was tested in extreme conditions and passed. The main issue is and will remain gas quality and trust in where you buy your fuel. Moisture freezes causing blockages in fuel lines and given enough of a temp drop can freeze the coolant in the block enough to pop freeze plugs. From the moment the engine starts the temp under hood begins to be too warm to be a threat. Other factors may create situations that make cold intake air a mute point. I'm no engineer but I have read many books and gained info on the matter of cold intake air.

 

[Cuda340]

IAT

Does IAT stand for Intake Air Temperature?

Yes. The IAT is the Intake Air Temperature Sensor. It senses resistance changes in response to the intake air temperature. The sensor resistance decreases as the surrounding air temperature increases. This provides a signal to the PCM, indicating the temperature of the incoming air charge.

 

[pwr2tow]

Cold only effects Hp and MPG.

The colder the air makes for more available Hp but colder then 62* ambient air starts a downward trend in MPG.

 

[Hal H]

I'll have to take a look at the TB on the Dodge, but many others frequently run coolant to preclude ice build-up around the throttle plate for low temp / high humidity conditions.

I recall my GM vehicles having coolant heating at the TB on their applications.

 

[70TA-09RT]

I don't think that the cooler IAT will be a problem after all it really pulls harder and the fuel density increases the hp and the direct cause is less milage. I would be more concerned if you are running the 180t-stat you could get codes for the temp not getting high enough. It just happened to me buddy with his 07 R/T Charger.

 

[DJR]

I read somewhere that cool air is good, but really cold air works against you - something about the air/fuel charge being harder to heat, or detonate, or something...

 

[randycat99]

That is my thinking, as well. It makes me wonder if I should have reconfig'd all of my cold-air intake stuff, had I known I would be driving in 30 deg weather over such a long trip, where mpg matters. The IAT was reading much colder temps than I had ever encountered before. Of all of the complexities and details of the logistics to this epic roadtrip, this little detail really caught me off-guard!

Up to that point, all of my efforts were focused on getting closer to that ambient temp at the IAT, which was always well above 60 deg, here in CA. It never occurred to me that I would ever see it dip far below 60 deg at the IAT in a different driving scenario. I just thought the temp would bottom-out somewhere around 50 deg or so, dominated by engine and engine bay heat. I guess I now know that my cold-air setup will follow the ambient temps right down into the freezing regime...

 

[STONEWHITE R/T]

Cold air wreaked havoc with carbureted vehicles if the choke did not close properly. Cold makes for lean conditions. But with FI the computer compensates with more fuel delivery.