S4/S6 questions

[Jens]

Hi Rob and Ethan, as I just read!

Besides what Michael Dewar writes correctly, let me add two things or
so.
The S4 was also available (in Germany at least) with a 4.2 V8 and 280PS
(206kW) from the Audi V8.
The S6 as it was called after the Audi 100 was renamed to A6 (as Michael
said), was available with these engines, too. Later a 326PS V8 was
available in the S6+!!
Brutal machine! But for tuning, you should stick to the turbo 20V which
has 230PS (engine code: AAN) stock but can be "inflated" to "Hooray".
(Unless that is you are willing to spend biiiig bucks on a V8-Biturbo or
V8-Supercharger/Compressor setup...)
Similar engines were used in the Audi 200 Type 44 20V (3B) and the Audi
S2 (ABY) (Audi "80" Limo, Coupe, Avant). Technically, you could count
the Sport quattro (KW) and RS2 (ADU) engines as "similar" as both have
20V, too and share some other components (Which exactly? Anyone knows?)
with the mentioned engines.
You might want to go to

http://www.audistory.com
->models->large: C->C4
for a starting point. Need some more pics on the C4...

h2h (hope to help) or hth (hope that helps) (<-are both right?)
Jens