Quote:
Originally Posted by Alpina_B3_Lux
I know we discussed that yesterday and I don't want to be splitting hairs here (although, you know my profession so I'm usually paid to do that  ), but the compression ratio for the Alpina B3S Biturbo is 9.4:1. See here: Alpina Catalogue (pages 17 and 26).
EDIT: Wanted to add that Alpina also mentions they're running 1.3bar of boost pressure (18.85 psi) which seems incredibly high to me. I wonder what they do to counter the problems of the N54 engine we're seeing here (except the lower compression)?
Master Batman |
Lawyers
I stand corrected
And yes, Alpina run up to 1.3bar of boost pressure but I am 99% sure that the top end of that is an overboost facility. Nevertheless, the lower compression pistons will allow higher levels of boost to be run safely. The exact component changes of the Alpina aren't really known, although I can probably get hold of the Alpina-specific parts disc to see what part numbers differ...