[McCloud]

My IATs are dropping as my RPMs go up. Super charged so should be the other way around. Any ideas?

 

[Nuke]

If I had to venture a guess, I’d submit the following:

The incoming air is rushing past the IAT sensor at an ever-increasing velocity, and that is accelerating the heat transfer from the tip of the heat-soaked IAT Sensor into the air charge, effectively chilling the sensor down to a cooler and cooler temperature until equilibrium in temperature is reached between the sensor and the air charge?

That’s the best I got...and it’s probably significantly biased toward old Mr Wizard episodes I’m subconsciously recalling, so take it with a grain of salt for sure...

 

[Hal H]

I'd agree with @Nuke - with my N.A. 392, its the same thing IAT will drop down a couple of degrees from cruise under sustained hard acceleration

 

[McCloud]

If I had to venture a guess, I’d submit the following:

The incoming air is rushing past the IAT sensor at an ever-increasing velocity, and that is accelerating the heat transfer from the tip of the heat-soaked IAT Sensor into the air charge, effectively chilling the sensor down to a cooler and cooler temperature until equilibrium in temperature is reached between the sensor and the air charge?

That’s the best I got...and it’s probably significantly biased toward old Mr Wizard episodes I’m subconsciously recalling, so take it with a grain of salt for sure...

Tbat works with an NA appljcation with the IAT sensor in the air intake tube. In my case it's in the intake manifold taking temp of the air after being compressed and run through the intercooler.

Sent from my SM-T350 using Tapatalk

 

[Nuke]

Tbat works with an NA appljcation with the IAT sensor in the air intake tube. In my case it's in the intake manifold taking temp of the air after being compressed and run through the intercooler.

Sent from my SM-T350 using Tapatalk

Well if the air charge being measured has just come through the intercooler, it should be cooler by virtue of just shedding heat inside the intercooler condenser, right?

IDK, I’m now flying by the seat of my pants ...

 

[landoawd]

intercooler.

Beak that word in half. Now look at the second part.

As you're ingesting more air at speed, you're no longer taking in ambient air in small gulps and you're passing air through the IC. You can see this reflected when your throttle closes and the IATs rise again at the end of the log.

 

[McCloud]

Well if the air charge being measured has just come through the intercooler, it should be cooler by virtue of just shedding heat inside the intercooler condenser, right?

IDK, I’m now flying by the seat of my pants ...

Sometimes seat of the pants works.. I appreciate the input either way.. That could be it if the intercooler is that affective, It could take accelerating a few times or running the track to really see an increase in temp. But man compressed air is hot, so I assumed even though it's going through the intercooler the temps should rise at 10lb of boost. Whipple does promote their intercooler as one of their advantages over other SCs. This is a write up on Ford (they have a big contract with them) but it drives the point if you are at all interested.

Twin Screw Superchargers 101: Here's The Whipple Difference

Ask, and you shall receive. Our friends at Whipple Superchargers out of Fresno, California, give us the full download on twin screw superchargers.

www.fordmuscle.com

 

[McCloud]

Beak that word in half. Now look at the second part.

As you're ingesting more air at speed, you're no longer taking in ambient air in small gulps and you're passing air through the IC. You can see this reflected when your throttle closes and the IATs rise again at the end of the log.

I just really thought the temps would go up with compressed air even with the IC. I was thinking my IAT was reading in reverse, but I guess this has to be actuals. Must be one affective IC.

 

[Hal H]

On the flip side, as I mentioned IATs will drop down during sustained WOT operation. When decelerating (throttle closed) the IATs will level off and can tick up a couple of degrees that I've observed. [I run the center display on IAT display]

I use Performance Pages to run virtual gauges for Water Temp / Oil Temp / Oil PSI pretty much all the time, unless I'm using navigation to get around to someplace I'm not familiar with (or taking alternate routes if traffic or road closures are an issue)

 

[Rockster]

My IATs are dropping as my RPMs go up. Super charged so should be the other way around. Any ideas?

View attachment 994443

Normal.

With my Hellcat I observe the same behavior with coolant temperature and oil temperature, though the latter lags coolant temperature.

More air flow through the inter cooler "radiator", the radiator, and the oil cooler brings temperatures down.

 

[Frank Julian]

Perfectly normal, increase in airflow, the air has less time to heat up and it actually cools the sensor.

I was stuck on the highway last summer due to an accident. traffic was creeping along, IATs were 114 degrees plus on a 90 degree day. Took 1/2 hour to go 5 miles to the nearest exit. Once I got off the highway and onto the road I punched it just to see and the temps dropped down to 98 degrees rather quickly (increased RPM plus the car actually moving in "clean air" and not sucking in exhaust from the car in front of it).

 

[McCloud]

Normal.

With my Hellcat I observe the same behavior with coolant temperature and oil temperature, though the latter lags coolant temperature.

More air flow through the inter cooler "radiator", the radiator, and the oil cooler brings temperatures down.

Thank you, real world data confirmation gives me peace of mind. Still new to the FI configurations, going through the learning curve.

 

[Rockster]

Perfectly normal, increase in airflow, the air has less time to heat up and it actually cools the sensor.

I was stuck on the highway last summer due to an accident. traffic was creeping along, IATs were 114 degrees plus on a 90 degree day. Took 1/2 hour to go 5 miles to the nearest exit. Once I got off the highway and onto the road I punched it just to see and the temps dropped down to 98 degrees rather quickly (increased RPM plus the car actually moving in "clean air" and not sucking in exhaust from the car in front of it).

Have to stress the sensor is not that massive to the point it has any real hysteresis regarding temperature signaling. This would defeat the goal of providing accurate at the "instant" data so the controller would be able to properly fuel engine engine, adjust timing, etc., all based on current conditions, not conditions that prevailed at any other time.

Any gradual drop in temperature is not the sensor shedding heat load but the hardware upstream of the temperature system losing heat as a result of the car moving and the natural cooing effect this has.

 

[Pioneer4x4]

Put the sensor after the intercooler and see what it reads, I bet that goes up as expected. (If I missed that in any post, I apologize)

 

[McCloud]

Put the sensor after the intercooler and see what it reads, I bet that goes up as expected. (If I missed that in any post, I apologize)
[/QUOTE

Whipple has them setup in the intake after the IC. I assume the HC's are setup the same way based on Rockster's coments.

 

[Rockster]

Whipple has them setup in the intake after the IC. I assume the HC's are setup the same way based on Rockster's coments.

Pretty sure the IAT is after (downstream) from the supercharger/inter cooler. With my other cars, some turbo charged, this is where the IAT (and MAF) was (were) located.

If it was located anywhere else it would result in the sensor reporting a temperature that did not reflect the true intake air temperature. This defeats the desire to have real time closed loop engine control.

 

[McCloud]

Pretty sure the IAT is after (downstream) from the supercharger/inter cooler. With my other cars, some turbo charged, this is where the IAT (and MAF) was (were) located.

If it was located anywhere else it would result in the sensor reporting a temperature that did not reflect the true intake air temperature. This defeats the desire to have real time closed loop engine control.

It is, I had to double check, they track temps in different locations similar to what Whipple is doing with Ford, but they do have the IAT validating temps going into the cylinder.

 

[Nuke]

Sometimes seat of the pants works.. I appreciate the input either way.. That could be it if the intercooler is that affective, It could take accelerating a few times or running the track to really see an increase in temp. But man compressed air is hot, so I assumed even though it's going through the intercooler the temps should rise at 10lb of boost. Whipple does promote their intercooler as one of their advantages over other SCs. This is a write up on Ford (they have a big contract with them) but it drives the point if you are at all interested.

Twin Screw Superchargers 101: Here's The Whipple Difference

Ask, and you shall receive. Our friends at Whipple Superchargers out of Fresno, California, give us the full download on twin screw superchargers.

www.fordmuscle.com

If was curious how their intercooler does its cooling, so I read the article, but it didn’t go into that kind of detail unfortunately. I did see this quote though, “This all equates to a lower discharge air temperature, and thus a more efficient mass flow of air.”

So it sounds like yours is operating as designed.

But if you want, I’d be happy to come get the car and do some extensive test driving in all conditions and under varying scenarios, just to make sure it will be okay for you going forward.

I could probably complete my testing in 2 weeks, or maybe 3 weeks tops. 😁

 

[EngiNerd]

If was curious how their intercooler does its cooling, so I read the article, but it didn’t go into that kind of detail unfortunately. I did see this quote though, “This all equates to a lower discharge air temperature, and thus a more efficient mass flow of air.”

So it sounds like yours is operating as designed.

But if you want, I’d be happy to come get the car and do some extensive test driving in all conditions and under varying scenarios, just to make sure it will be okay for you going forward.

I could probably complete my testing in 2 weeks, or maybe 3 weeks tops. 😁

And if we're to trust the results I'll have to validate them afterwards. Ya know, for accuracy and stuff.

 

[Nuke]

And if we're to trust the results I'll have to validate them afterwards. Ya know, for accuracy and stuff.

I would expect no less and frankly think poorly of you if you didn't try!