Source: Car and Driver
By: Juergen Zoellter
More pictures here.
By: Juergen Zoellter
The Mercedes-Benz SLR McLaren, which debuted in 2003 and is wrapping up production this year, was a car as convoluted as its name. The unhappy child of bickering parents, the SLR came out too heavy, too big, and too unprofitable. Now that the Mercedes-Benz/McLaren marriage has dissolved, both sides are coming to their senses. For McLaren, that means developing a lightweight, mid-engine supercar codenamed P11, a car you'll be reading about here soon. For Mercedes-Benz, it means going back to its sports car roots with another Gullwing, the SLS AMG.
Inspired by the 300SL coupe of the 1950s, this new SLS also has the bobbed tail, football-shaped grille, and bottom-mounted door handles of the original. Where it differs is, well, pretty much everywhere else. Indeed, AMG boss Volker Mornhinweg says the SLS is no simple homage. ?We did not build a retro car at all,? he says. ?It is the most advanced supercar you can find today!? The SLS is 182.7 inches long and rides on a 105.5-inch wheelbase, figures roughly equivalent to those of the Lamborghini Murci?lago LP640. The entire car is constructed out of aluminum; the space frame weighs just 530 pounds.
Reengineered Engine, All-New Gearbox
Climbing into the driver?s seat of the new SLS AMG is surprisingly straightforward?the sill is easier to clamber over than the old 300SL?s?but you?ll need every inch of your left arm to reach the strap you tug to close the gullwing doors. The view out the front is dominated by the loooong hood, which provides shelter to the heart of the reborn Gullwing: a 6.2-liter, AMG-built V-8. Known internally as the M159 engine, the SLS?s V-8 is a reengineered version of the M156 V-8 found in the C63, E63, and S63, among others. The M159 has an all-new magnesium intake with individual velocity stacks, a reworked valvetrain, and revised camshafts. The tubular steel headers are further optimized for flow, and the exhaust system is similarly changed. Output stands at 563 hp at 6800 rpm and 479 lb-ft of torque at 4750 rpm. The engineers also switched to dry-sump lubrication in order to mount the engine very low in the chassis, which imparts a lower center of gravity, and the entire mill sits behind the front-axle line.
VEHICLE TYPE: front-engine, rear-wheel-drive, 2-passenger, 2-door coupe
ESTIMATED BASE PRICE: $175,000
ENGINE TYPE: DOHC 32-valve V-8, aluminum block and heads, port fuel injection
Displacement: 379 cu in, 6208cc
Power (SAE net): 563 bhp @ 6800 rpm
Torque (SAE net): 479 lb-ft @ 4750 rpm
TRANSMISSION: 7-speed dual-clutch automated manual
Wheelbase: 105.5 in Length: 182.7 in Width: NA Height: NA Curb weight (C/D est): 3600 lb
PERFORMANCE (MFR?S EST):
Zero to 60 mph: 3.8 sec
Top speed (governed): 196 mph
The V-8 hooks to an all-new, seven-speed dual-clutch gearbox integrated into a rear-mounted transaxle. The connection is made via a carbon-fiber driveshaft housed within a torque tube, which ensures a very rigid link between engine and transmission. There are four driving modes: Controlled Efficiency, Sport, Sport Plus, and Manual. The Race Start launch-control mode guarantees neck-snapping starts, and the stability control is selectable to on, off, or Sport.
It?s as Incredible to Drive as You Imagine
Once the engine is ignited?via a button on the dash, naturally?it idles with a deep thrum. Toe the throttle a bit, and the revs gather quickly, as in a race engine, and the aural accompaniment becomes more metallic in tone. Lift the throttle, and engine speed drops as quickly as it rises. Floored from a stop, the acceleration is nothing less than explosive: Mercedes claims a 0-to-62-mph time of an astonishing 3.8 seconds. (Mercedes estimates are notoriously conservative.) The engine note under load is a throaty war cry that changes into a sort of zinging buzzsaw above 4500 rpm. The engine response above 6000 rpm is as direct as any we?ve ever felt?and that includes the Ferrari F430?s masterful V-8. Top speed is governed at 196 mph.
The SLS understeers slightly on corner entry, but the optional carbon-ceramic brakes, immediate throttle response, and talkative steering?perhaps the sharpest rack ever to be fitted to a Mercedes road car?make repositioning the car a snap. Give it mid-corner throttle, and car gently transitions to easily controllable oversteer. The SLS is wonderfully neutral (helped by the near-ideal 48/52-percent front-to-rear weight distribution), and sitting so close to the rear axle means you can easily determine what the car?s doing and take immediate action. It is mind-blowingly simple to drive the SLS quickly.
High exit speeds are aided by a mechanical limited-slip differential that offers 30 percent lock under load; it provides 60 percent lock under deceleration. Grip is high, to say the least, thanks in part to the Michelin Pilot Super Sport tires developed especially for the SLS. They measure a beefy, 295/30-19 in the back and 265/35-19 up front. Suspension is by forged aluminum wishbones all around, and a wide track (66.1 inches in the front and 64.9 inches in back) imparts stability. The coupe will eventually spawn an SLS roadster and the SLS eDrive, which is a fully electric version that replaces the raucous V-8 with lithium-ion batteries and four individual electric motors.
The new Gullwing is incredible; even in this prototype form, it is clearly every bit the driver?s car the SLR wasn?t. We won?t be able to afford an SLS when it goes on sale next spring?unless it?s a ?95 Cadillac SLS that pops up on eBay?but those with the means will be able to nab one for $175,000 or so. We?re already green with envy.
More pictures here.