ILUVTTS1
04-15-2016, 04:16 AM
Hey, I'm a big Audi buff and I've got a sorta weird question that i'm sure someone here can answer...? So obviously the 4.2 was in use for a lot of years... I recall my dad's old D2 S8 having 360hp from factory... though my brother's B7 S4 has 340? Where is the extra horsepower coming from in the S8 4.2 and why wasn't the same thing done to models much later such as the B7 S4... 6 year difference but 20 less power...? Given 20 horsepower is marginal... But what am I missing?
Thanks in advance lol sorry for such a random question.
4rings2turbos
04-15-2016, 05:48 AM
The only thing I can guess is, like the current S8, there is no RS 8 so they bump the power up on the S8 to kinda fill that gap (look at C7 S6/7 and RS 6/7 power and compare to the S8. The S8 is much more S than the 6 and 7 despite same engine). The extra power came in a tune and higher flowing intake components.
Another tidbit of detail to make it more difficult: the B6/7 S4 engine (along with the 4.2L allroad) have a chain driven version of the same V8. B6/7 producing 340hp and the allroad 300 (mostly down to tune, though there are some hardware tweaks). The C5 A/S6 had the same belt driven 4.2 making 300 in the A6 and 340 in the S6. All of the intake bits can be swapped over to other belt driven 4.2s to make up the power difference.