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Could anyone please offer technical information and/or specifications, as to how the overboost feature operates?

My understanding is that typically, overboost holds the peak torque for longer in the RPM cycle; but it generally does not go over the peak? Maybe this is not correct?

Whereas for the T5, the peak torque of 266 is increased to 295 during the cycle. Hence, the torque is both greater and held for a longer period during the overboost burst? Is this correct??

Regarding overboost, I am very curious as to what exactly happens, how it is triggered, how it is released,...

Also, why didn't Volvo combine selectable shifting with the sport mode overboost? (you can only select a precise gear while in "D" not "S"? And is there a Winder mode "W" to do the inverse of the "S" mode?? )

Volvo seems to be nicely pushing the envelop on this technology, any information is much appreciated; thanks.
 

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I am under the impression that "overboost" is a higher-than-sustainable boost that, if continued for a long period, would cause damage or excessive wear (too much heat for instance).

It is only "over" because it is higher than can be continiously used.

I believe it is triggered by high engine load (i.e., heavy throttle).

To engage "Sport" mode on the transmission, you go from "D" to the selectable shifting area. You can change from "Sport" to select shift by pushing/pulling on the shifter to make the gear change selection up/down.

What would you want "Winder" mode to do?
 

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I can say Volvo isn't the first to use it. I know off hand Porsche used it and some others.

ECU simply allows higher boost for a set period of time under full throttle by allowing more boost simply by closing the wastegate more (I dunno the PSI of the turbo, I don't know if it fully shuts or closes more then 'normal'). After the time is up or full throttle acceleration is relaxed, it opens up a bit and drops pressure.


Though I think its more so geared toward fuel economy as more boost=more fuel. IT sure does help longevity though.

And there is no winter mode. just shift to 2nd or 3rd.
 
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