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      12-12-2010, 03:42 PM   #60
Alpina_B3_Lux
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Quote:
Originally Posted by E92Fan View Post
The standard compression ratio of the N54 engine is 10.2:1, whilst Alpina use a 9.3:1 piston in their B3S.
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)?

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