2009 Mercedes-Benz SL 63 AMG review and pictures

Posted on Friday, 8 February 2008 , 13:02:15 byAngela

Filed under MercedesConvertiblesCoupesCabriolet

Mercedes-Benz SL 63 AMG

For 2009 Mercedes-Benz unveiled a fourth member of its iconic SL sports car family " the SL63 AMG. Perhaps the sportiest SL roadster ever, the new SL63 AMG is powered by a 6.3-liter, all-AMG V8 engine that™s coupled to a newly developed MCT transmission. Featuring an innovative start-up clutch that replaces a conventional torque converter, the seven-speed MCT (for multi-clutch technology) transmission combines the direct connection of a manual gearbox with the lightning-quick automatic gear shifts of a Formula 1 race car. Topping off the SL chassis is an even more agile AMG sports suspension based on the Mercedes-Benz ABC active suspension.

The First Engine Developed From the Ground Up by AMG

The SL63 AMG is powered by an AMG 6.3-liter V8 engine that features four valves per cylinder, variable valve timing, bucket tappets (rather than rocker arms) and a variable intake manifold. Sharing no parts with Mercedes-Benz V8 engines, the 6.3-liter engine was a completely autonomous development at AMG.

Built almost completely from a high-strength silicon-aluminum alloy, the cylinder bores make use of a twin-wire-arc-sprayed (TWAS) coating, a process that results in impressively low friction and running surfaces that are twice as hard as conventional cast-iron cylinders.

The 6.3-liter engine block boasts an especially rigid bedplate acting as the overall support of the main bearings (similar to a one-piece set of main bearing caps), cast-in steel reinforcements and a sturdy closed-deck layout in the cylinder head area. The high-flow intake and exhaust ports form a vertical straight line, helping the 6.3 AMG engine rev freely to more than 7,000 rpm, yet the highly flexible AMG engine still produces nearly 90 percent of its peak torque at only 2,000 rpm.

A finely balanced crankshaft with six counterweights spins in five main crankshaft bearings. The crankshaft counterweights feature heavy metal plugs " a detail usually found only in racing engines " which means they can be significantly smaller, increasing power by reducing rotational inertia and oil drag.

Each forged connecting rod is precisely “cracked” with the help of a laser beam, so the irregular fracture contributes to its strength when the two halves are clamped around the crankshaft. The connecting rods and lightweight pistons are matched for extremely close weight tolerances that contribute to smooth running at high speeds. Small nozzles in the engine block spray cooling oil onto the underside of each piston crown.

“Bucket” Followers Instead of Rocker Arms

Twin overhead camshafts in each cylinder bank open the 32 valves via bucket-type followers. In other words, instead of rocker arms, the cam lobes sweep across the flat top of the followers, which sit directly on top of the valve stems. This space-saving design provides a very stiff valve train that allows for large valve openings and dependable high-speed operation for maximum horsepower and torque. However, in contrast to racing engines, each bucket incorporates a hydraulic lifter that automatically maintains valve clearance, which allows for long service intervals and low costs.

The AMG V8 makes use of variable intake and exhaust valve timing to maximize efficiency and torque over a wide RPM range. Valve timing can be automatically adjusted within a range of 40 degrees using electro-hydraulic vane-type adjusters on each camshaft. At part throttle, the valve timing adjuster keeps the exhaust valves open as the intake valves are opening, using this valve overlap for internal exhaust gas recirculation, reducing exhaust emissions and improving fuel economy. However, approaching full throttle, the camshaft adjustment optimizes valve timing for maximum power. The intake cams are driven by a double chain from the crankshaft, and small gears on the intake cams in turn drive the exhaust cams.

Unique Styling Touches

The SL63 comes with a distinctive AMG front hood that™s noticeably different from other SL models, as well as a new front apron with a more pronounced wedge shape, larger cooling air intakes, and a black grille. Bi-xenon headlights with black surrounds and large round fog lights ringed in chrome and set well to the side emphasize the vehicle™s width.

Hot air from the engine exits through side air outlets in the front fenders and from the “gills” behind the front wheels. Trim panels finished in matte silver with “6.3 AMG” lettering catch the eye, as do new outside mirrors with arrow-shaped LED turn indicators.

SL63 AMG body styling also includes deeper AMG side sill panels and a beefy-looking rear apron that incorporates a large black air diffuser and two pairs of chrome tailpipes. An AMG rear lip spoiler on the trunk lid reduces lift, especially at high speeds.

Finished in nappa leather and genuine carbon fiber, the interior features standard AMG sport seats, an AMG three-spoke steering wheel and a sport instrument cluster with red tach and speedometer needles that swing to the max position and back whenever the ignition is turned on.

From Coupe to Roadster in 16 Seconds

At the push of a button, the SL™s retractable hardtop can be fully opened or closed in just 16 seconds, transforming the car from a quiet, weather-tight coupe to a top-down open-air convertible. A hydraulic pump and 11 computer-controlled hydraulic cylinders power the system, and roof operation is controlled by a switch on the center console. A clever folding design allows for a surprisingly large cargo area of 7.2 cubic feet when the top is down. With the top up, the trunk holds 10.2 cubic feet.

High-Performance Braking

Excellent stopping power for the SL is provided by large, four-wheel disc brakes enhanced with four-channel ABS anti-lock control. Matched to its power and speed capability, the SL63 AMG comes with large 14.2-inch vented rotors up front and 13.0-inch vented rotors at the rear, while the SL65 AMG boasts vented discs that are another 1.2 inches in diameter.

Also new are 19-inch AMG staggered-width alloy wheels " 8.5 and 9.5 inches wide " fitted with 255 / 35 R 19 (front) and 285 / 30 R 19 (rear) tires. With triple-spoke styling and a titanium grey finish, the AMG alloy wheels complement the new AMG body styling.