Originally Posted by mkoesel
And 408hp for the B3 GT3 is not too shabby for what I assume is a tuned N55. That's assuming it has some sort of warranty.
The Alpina B3 BT always uses the N54, not the N55 engine. You cannot extract that much power from the N55 with its single twinscroll turbocharger.
The B3 GT3 is basically a B3 S BT with a KW3 suspension, StopTech brakes and an Akrapovic exhaust, as well as slightly different wheels and race seats.
And of course any Alpina car retains the full BMW warranty. They're produced in BMW factories anyway.