http://www.insideline.com/mclaren/m...drive.html 

3.8L twin turbo V8, 592hp, 21.8psi peak making 443 lb-ft of torque from 3k-7k rpms.  That's not the really interesting part though, and we already talked about the hydraulic sway bars.  The interesting bit is that McLaren decided to use an open diff and brake-steer technology that was used in F1 before banned.

That's pretty cool. And funny. I wonder if they did that just because they named the car MP4-12C.

(Explaination: The first F1 car known to have used brake steer was the McLaren MP4/12, their 97 challenger. They used a manual system consisting of a second brake pedal which operated on only one rear wheel and a toggle switch to select which wheel to use it on. They made it part of the core design of the MP4/13 only for a reporter to publish photos of the pedal box. The ensuing political maelstrom caused the FIA to do an about-face and ban the system despite it being declared legal at the beginning of the year. Not that it mattered - they walked away with the 98 championship anyway.)