Herrin811

I doubt anyone monitors underhood temps, but maybe someone has a good guess...

Wondering what kind of temps the components are exposed to in the engine compartment...I am sure they would be hotter on the exhuast side, due simply to radiant heat...

I'm also wondering how much heat intake air absorbs from the turbo, and how much is heat dissipated across the intercooler....

I know we're shooting for 70-80 optimum at the intake horn, but I have never seen anything about the rest of these temps??

RowJ

You'd be wrong!
Infidel ran a test. Parts of which I bookmarked....
"It's hot everywhere under the hood. My intake temp as measured at the intake horn a few inches from the grid heaters is almost always a constant 20° higher than the outside temp with the stock airbox.
With the BHAF it was 26° higher. 6° may not seem like much but it's more than 25% hotter than the stock box.
I've never figured out how intake temp relates to egts, it's probably a complex formula, but am certain it isn't a one to one ratio. I'd venture to say it's more like 10° or more higher egt for every 1° rise in intake temp."
This is mostly intake air but...
There is a thread on another site where they placed sensors all around under the hood. While moving - the 20* above outside air temp works as a rule of thumb!
Interesting to note that Fuel temps also run about 20* warmer than outside air temps as well.... any time of yr!

RJ

KATOOM

Not sure if this matters or not since its not a scientific readind but one hot summer day when I got home I popped the hood for whatever reason (cant remember) and touched the intake horn. It was very cool! Much much cooler than any underhood item. It was almost, with out sounding ridiculous, cold. The one thing that has to figured is that I touched it almost as soon as I got in the driveway and lifted the hood. Any time left draging my feet results in heat soak making everything the same temp. Needless to say I was very surprised.

mikmaze

it would be extremely easy to monitor underhood temp, get out there and un mount the ambient air temp probe at the front of the truck and move it to inside the engine compartment. drive around with it zip tied to a few locations and watch the overhead display. wires too short? heck extend them. I might do this for the next phase of checking effects of losing the plastic air dam to the left of the cooler that I think lets more cool air in to reach my BHAF.

Bart Timothy

I can't speak to the 3rd gens, but underhood temps of the 2nd gen depend on where, under the hood, you measure and whether the truck is moving down the road, or not. I did my tests using a 3 probe digital refridgeration super heat thermometer, using air temp probes, on a hot summer day. I can't remember the exact readings now, except for those inside the stock air cleaner, which were the ones I was looking for. In general, the left side was hotter than the right, the back was hotter than the front, and the top hotter than the bottom, if I remember right.

I found that driving down the road at any speed greater than 15 or 20 mph, the inside air cleaner temp was never any greater than 2-4* above ambient outside temps. When stopped for a red light the temps slowly started to rise to 10-20* above ambient depending on how long the light was. After starting out from the light, the temps would quickly drop.

These findings were with the stock, unmodified, air cleaner box with the rubber boot to the fender still installed. My guess, with a BHAF instead, the air intake temps would be greater than stock just by the fact that the metal grid surrounding the filter is usually very hot to the touch when I've touched them, but I never actually measured their air temps. Not even a heat shield with the BHAF seems to help much, in my experience. The stock 2nd gen plastic air cleaner box, drawing from the fender, does a good job of getting cool air into the engine..

On a 3rd gen using a BHAF, with the filter up front, the findings might be different, but my guess is any open exposed air filter will draw in warmer air than an enclosed one drawing from the outside.