QUOTE (Sengir @ Nov 25 2011, 07:35 AM)

During the 4–6 day peak of its 28-day cycle, a loup-garou will become savage and go berserk as a Bear shaman (see p. 192, SR4) and is treated as if it had a rating 2 adrenaline pump (p. 338, SR4).Emphasis mine

And yes, an Adrenal Pump works for Rating * 1D6 Turns (not Rating D6 turns) and after those turns hits the poor character with an equivalent amount of damage, so I'm not sure where TJ got the "no more than 3 boxes" from...
From the fact that you only go Beserk for the duration of your roll (0-3 Rounds). WHILE YOU ARE BESRERK, you have the equivalent of a Rating 2 Adrenal Pump. Pretty cut and dried, actually. You Go Beserk and get the Benefits of Adrenal Pump. When you are not Beserk, You do not get the benefits of an Adrenal Pump. A Loup-Garou will only ever go Beserk for 0-3 Turns at a time, according to the mecahnics. What more needes to be said?
You could, of course, ignore the mecahnics and do what you want, but then you have drifted from the rules at that point.

And yes, the normal Adrenal Pump functions as for 1D6 x Rating Turns. However, The Loup Garou does not have a physical pump. His boost is dependant upon his Beserk State. If he is not Beserk, he gets no boost.