Originally Posted by Pete_vB
Mmm. Awesome car.
You may know that the RS4 and the Audi R8 share the same motor, 4.2L V8. You may also know that the V10 version of the R8 shares the same motor as the Gallardo...
Due to all this sharing, the V10 and V8 were designed to be fairly interchangeable within the chassis, and this means the humble A4 (or S4 in his case, not an avant) will accept the motor from a Gallardo as if the factory designed it that way. You still need an all new exhaust and getting the electronics to play nice is a trick, but for shocking the Ferrari in the next lane it's pretty hard to beat one of those dropped into a 4wd avant.
I am very familiar with the rs4/r8 v8s. I know the r8 was built leaving plenty room in the engine bay to drop a v10. Many have done the swap already.
However, the rs4 v8 is absolutely crammed in the engine bay with most of the motor hanging in front of the front axle (which is also the biggest knock on an otherwise perfect car). This is where the M cars get it right.
Trust me when I tell you there is no room for anything, not a turbo or any size able S/C. I would love to see how they fit the extra two cylinders etc in there.
Drop me a pm with info/photos when you get a chance..
Sorry OP... Here is my contribution...
R8 is next..