Add flame rings and this is what Motronic can give you for a few seconds each time you boot it

This is around peak torque (3900-4800rpm and does go as high as 1.5bar under different atmos conditions) at higher revs it will typically give 1.1 to 1.2 bar overboost
BTW I have a 16 second .MOV file which shows the overboost in action - if anyone can host it please PM/email me - cheers