The now retired V10 S85 engine from the E60 M5 and E63/E64 M6 continues to live on in many a project car and in racing applications (example
Long time BMW tuner, Dinan, has just finished development of a custom BMW S85 motor, which has been bored and stroked to 5.8L (from 5.0L). Combined with performance cams, dry sump oil system, a racing exhaust, and custom software tune, this hopped up engine produced 720hp (@8300rpm) and 497lb-ft (@6900rpm) on 98 octane race gas. It was designed for use in the Riley Technologies MkXXV track day car
Check out the engine's dyno video below.