rs4 v8 fsi transplant is possible only within the last few months thanks to this
http://www.youtube.com/watch?v=dFqu96otScs
the adaptronic.nl is the first ecu controller to operate the fsi system and drive by wire.
but the gm ls3 is still the best transplant for cost and power, only it's 5" longer that's why it needs the s5's gearbox.
shortest engine is s4/rs4, the one in middle is our s8's belt drive 4.2, and last is chevy ls series from corvette.
am happy to share the one year of research i've done on s8 engine repairs/alternatives,
me and mike are not secretive with our club buddys amar. just ask.