[s-cars] Question about compression ratios and tuning

[Mihnea Cotet]

Yes the AAN has 9.3:1, but only when it has a paper head gasket.

HTH,

Mihnea

At 10:40 2/02/2004 -0500, QSHIPQ at aol.com wrote:
>According to AST "Motronic Engine Management System for the Audi S4 and the
>4.2 Liter Audi V8" the AAN motor in the USA carries A compression ratio of 
>9.3:1
>
>SJ
>In a message dated 2/2/2004 9:36:32 AM Central Standard Time,
>mik at info.fundp.ac.be writes:
>According to Audi, a 3B has 9.3:1 CR, just like an AAN. According to my
>experience, an AAN with metal head gasket has 9.0:1 CR, just
>like an ADU (RS2 motor).
>
>I haven't been able so far to say that a 3B has 7.8:1 CR, this would mean
>that the knock limits of the motor are much further than on an AAN, and
>this just isn't the case...
>
>HTH,
>
>Mihnea