Expected IAT range for turbo?

Post by **prwood** » 26 Jun 2019, 12:58

What's the normal expected operating range for Intake Air Temperature on a turbocharged, intercooled engine? Today with outside air temps at 77F, my 2.4T was reading IAT of ~147F when idling and ~115F while driving at 50mph. Just curious if that is normal or not.

XC70Rider · Post by **XC70Rider** » 26 Jun 2019, 13:22

prwood wrote: ↑26 Jun 2019, 12:58 What's the normal expected operating range for Intake Air Temperature on a turbocharged, intercooled engine? Today with outside air temps at 77F, my 2.4T was reading IAT of ~147F when idling and ~115F while driving at 50mph. Just curious if that is normal or not.

If the A/C was on then 115f is normal for highway driving but 147f at idling appears too high.

My air intake spikes ~20f higher when the A/C is on. The air intake on my P2 does drop a few degrees when the thermostat opens and drops the coolant temperature. The over the engine pipe is pretty close to the engine.

After she cools down I'm going to remove the Beck Arnley thermostat and throw the OEM back on. Just need to drain ~1/2 liter from the petcock screw on oil cooler pipe and clamp down the hose from the reservoir. I'll post in my thread if it drops the engine and air intake temperatures.

viewtopic.php?f=9&t=88751

Post by **prwood** » 26 Jun 2019, 13:43

XC70Rider wrote: ↑26 Jun 2019, 13:22
prwood wrote: ↑26 Jun 2019, 12:58 What's the normal expected operating range for Intake Air Temperature on a turbocharged, intercooled engine? Today with outside air temps at 77F, my 2.4T was reading IAT of ~147F when idling and ~115F while driving at 50mph. Just curious if that is normal or not.
If the A/C was on then 115f is normal for highway driving but 147f at idling appears too high.

The A/C was on in both cases. Knowing that this could affect the temp, I'm going to try some additional testing with and without A/C.

Post by **abscate** » 26 Jun 2019, 15:11

Give me a few days to map mine, Peter.

Post by **prwood** » 27 Jun 2019, 11:10

After some further testing, I can confirm that IAT is around 95-100F with the A/C off, when driving, regardless of speed. IAT goes up to 115F with the A/C on (presumably because the heat emanating from the condenser reduces the effectiveness of the intercooler). Idling results in IAT of 140-150F, whether or not the A/C is on.

Outside air temps have been around 73-77F.

Post by **abscate** » 27 Jun 2019, 11:43

On our turbos, the MAF measures temp to give the ECU the best mass balance but then under heavy boost, my guess os the ECU has to correct again for the temperature of the boosted air, to get metering right. Thus, you get two cool sensors on the last piece of induction pipe on a turbo.

Those two sensors arent cheap by the way. I have a spare pressure one if someone needs one for troubleshooting.