Power loss with increased IATs?

[RallyMachine]

Let me just preface this by saying, that these numbers are just what I'm getting on an Airboy dyno by uploading 3rd gear logs. Car was initially tuned on a dynojet where it put down 305whp/350wtq. Car has since been retuned via an e-tune

 

I uploaded a log I did over the winter after completing my etune when ambient temp was around 30* or so and got results of 306/350. I was happy with this cause this matched the dynotune numbers almost exactly.

 

Now ambient temps are about 80* and I just did a pull and am only getting numbers of ~270whp/310wtq.

 

Is such a significant drop in power expected with the rise in temperature?

[BrandonspecB]

Totally normal.

 

50 degree difference is huge.

 

If you use virtual dyno you can correct for air temperature differences.

[PtPixel]

Yes, it's as expected. Warmer temperatures will lower your intercooler's efficiency meaning that the air in your intake manifold will be at a slightly lower pressure (from the warmer air). Differences in humidity will also have a similar effect.

[RallyMachine]

Ok that's a relief to hear. I input all the correcting factors into the virtual dyno (tire size, temp, humidity, elevation even!) Still got about the same number, but I don't think it can account for the fact that there is physically less air flowing at the warmer temps.

[jackal8788]

As long as you make the proper atmospheric corrections, the numbers should match. The higher temps don't necessarily reduce the volume of air that is flowing, they just reduce density so the mass of air (oxygen) is lower than it would be at cooler temperatures. Nice numbers though!