Gullwing exposed!

Mercedes-Benz has taken the unorthodox step of releasing official spy pics of its flagship Gullwing coupe ahead of its unveiling at the Frankfurt Motor Show in September. Mercedes has also confirmed a raft of technical details and the name – SLS AMG – before it hits European streets early next year. Australian deliveries are scheduled for 2010.

The SLS AMG will replace the McLaren-built Mercedes SLR as the three-pointed star’s ultimate sports car. It’s been developed in partnership with AMG and specialists at its Mercedes Technology Centre in Sindelfingen and won’t carry the SLR’s stratospheric price tag.

Built around a lightweight aluminium spaceframe with a near-perfect weight distribution of 48/52 percent and a relatively lithe kerb weight of 1620kg, it’s powered by a front-mid-mounted hi-po version of the 6.2-litre AMG-developed V8. The SLS AMG will match the SLR with 100km/h coming up in 3.8sec and a top speed of 315km/h.

The engine is based on the M156 6.2-litre V8 used in most mainstream AMG models, however it has been thoroughly re-engineered for the SLS with a dry-sump oil-delivery system, an all-new intake system, a revised valvetrain and camshaft profiles, and a tailored exhaust. Despite the use of high-strength components to handle the added stresses (such as forged pistons, a reinforced crank bearing and stronger crankcase structure), the M159 6.2-litre V8 actually weighs less than the regular version, tipping the scales at 206kg.

The overall result is maximum power of 420kW at 6800rpm and peak torque of 650Nm at 4750 – compared to its current 386kW/630Nm personal best in the CL63 AMG. A carbonfibre driveshaft in a rigid torque tube delivers power to a rear-mounted seven-speed dual-clutch transaxle. The gearbox has four shift modes, ranging from a comfort mode for highway cruising to a quick-changing mode with a launch-control function for track driving.

The suspension places double wishbones on all corners with forged-aluminium hub carriers to reduce unsprung mass, and 19 x 9.5-inch and 20 x 11.0-inch alloys on the front and rear respectively. The stopping department is taken care of, at the extreme level, by optional carbon-ceramic brakes.

While Mercedes is yet to reveal pricing for the SLS AMG, it is expected to undercut the $600K price-tag worn by the SL65 AMG Black Series by a substantial margin, with the Aussie list price expected to be around $450,000.