Here's a summary of what's under the hood (click on the terms for more information). Like most supercars, the SLR is built around an extremely powerful engine. The 332 cubic inch (5.5 L) V8 engine was hand-built by AMG, a company that usually modifies Mercedes-Benz street cars into full-fledged race cars.
Both the block and the heads are aluminum, with single overhead cams and an 8.8:1 compression ratio. A twin-screw Lysholm supercharger with two intercoolers cranks the horsepower up several notches. A dry sump system allows the engine to be mounted lower, dropping the car's center of gravity. This placement allows for 617 horsepower at 6500 RPM. The torque is just as impressive with 575 foot-pounds at 3250 RPM.
Power transfer is handled by a five-speed "manumatic" transmission -- the driver can shift electronically at the push of a button. Mercedes' Electronic Stability Program (ESP) helps drivers handle all that power by constantly monitoring traction, adjusting torque, and selectively applying the brakes to prevent the car from spinning out of control. The ESP system has both a full setting and a setting that puts more control into the hands of the driver, but it can't be turned off completely. Mercedes feels that more than 600 horsepower is a bit much for even experienced drivers to handle, an opinion backed by test drivers at Car and Driver magazine.
McLaren reports that the SLR can go from zero to 60 mph in 3.8 seconds, with a top speed of 207.5 mph. Car and Driver reports an even faster zero to 60 time of 3.6 seconds [ref].
Next, we'll see how this dream car handles.