Boost in cold weather

[igor136]

Car is urs6 2.2t.
I have a strange problem.
When the outside temperature is 25+ degrees Celsius, car is going very well.
Boost is 1.1 bar.
But if the outside temperature is lower than 20, car is much lazier.
If the outside temperature is 10 degrees, the boost is 0.8 bar.
G42 sensor is good. I have no problem with starting the engine. Consumption is 8-13 liters. I tried another MAF and lambda probe. Same
Any ideas

[UrS4boy]

Any ideas

Yes there was a "story" told that the Audi engineers obviously knew that colder air was denser, etc. and therefore, relative to warm temps, the performance at colder air temps would be greater at the same boost levels as warmer air temps. As a result, the story continued, they decided it would be best if they decreased boost at colder temps so the overall performance would be the same at all air temps.

MTM and the like said forget that B***sh*t and allowed the same or higher boost levels at colder temps.

Don't ask for a reference. It would take me way too long to find it, if I could. This goes back to 1998-99 or so on a forum that no longer exists.

[igor136]

Thanks Dave. So, that is normal?

[igor136]

Is this normal acc? It was small boost leak at T pipe.

[hunker7]

Mine is off the road currently so can't check, but I haven't noticed a difference in boost levels between temperatures.

EDIT: Acceleration looks good.

[igor136]

Fuel pressure is 4.2 bar on idle. Is that ok?

[Rusty]

ABY does indeed drop boost depending on temps but what you describe sounds like the over boost function not being triggered. Not sure of the exact conditions required but generally, high gear, low revs and quick application of full throttle triggered it for me.

Get a remap / chip and enjoy proper.oerformabxe of the k24 hairdryer

[hunker7]

Overboost on my S4 is triggered at/above 3000rpm at WOT.

[igor136]

Thanks for replays. Car not pulls always the same. Sometimes i have 2.2 bar on display and sometimes 1.7. In summer always 2.1-2.2
I have to chip the car, I know. But I want to be sure that everything is alright first.

[veneto rs2]

on this i can definetely say that my RS2 performs a lot better on cold weather.
specially on low revs.