words: Greg N. Brown

Laguna Seca, California —

Everything I know about diagnosing the addled mind comes from watching Woody Allen movies, so I'm no expert. But it's clear that Arnd Meyer and his colleagues at Mercedes-AMG are as mad as March hares.

It's not just that Meyer, senior manager of vehicle dynamics at Mercedes' skünkwerks, is quick to flash the mile-wide smile of someone who hears punch lines to untold jokes, talks as if he's about to bust out of a Looney Toon, or drives, as he gleefully admits, "a little bit crazy." Nope, the clearest sign of Meyer's marginal hold on reality is the company he keeps in the company where he works: AMG, Mercedes-Benz's Haus für die Unheilbare Geschwindigkeitsmissbildung (Home for the Incurable Performance Freak).

Meyer exhibits all the signs of the high-octane personality type that devotes infinite energy to an essentially gratuitous task — such as holding an endless tea party or, in Meyer's case, working in the outfit within AMG called the AMG Performance Studio that builds excessively powered, hyper-expensive automobiles no one needs but everyone wants, like the new SL65 AMG Black Series. The Black's hawkish carbon-fiber body panels, 670 horsepower, and estimated price of $300,000 qualify as lunacy to most sentient creatures, but to Meyer and his buds (and, admittedly, to your slightly unhinged correspondent), this ultimate SL is reason enough to drill, baby, drill.

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Situated up the road in Affalterbach, out of sight of their more serious kin at Mercedes HQ in Stuttgart, AMG's band of merry tweaksters puts up a respectable front, designing bodywork and hand-building engines and the like for that very fine line of AMG-badged passenger vehicles. But, after-hours, in sub-basements and anonymous rooms, in remote machine shops and deserted labs, certain inhabitants of the home perform the Black Series arts of excessively wretched excess, and there's only one rule: Forget it's a "passenger" vehicle. Think only about the driver. Think only about performance.

Their latest concoction is the third in an ongoing series of Mercedes-Benzes you'll never want to lend to the housekeeper to pick up the dry cleaning. Only 350 will be built, 175 for America. Furthermore, it's best to keep such lunacy out of too many hands. I should know. I was loopy too after driving the SL65 Black from San Francisco to Monterey and then on the twists, climbs, and fall-offs of Laguna Seca's racetrack.

Just before the track session began, I peered from my helmet at AMG's affable chief, Volker Mornhinweg, perched on Laguna's pit wall, watching a huddle of journalists about to abuse the ultimate expression of his group's fixation with speed. Earlier, he'd told me the project's goal was to create a "lighter, faster, and more powerful SL," but his frizzy coif, demonic grin, and bespectacled eyes glimmering with the luminosity of a true believer told me much more about the Black Series than his words. No mad scientist has ever looked more proudly at his monster than Mornhinweg did at the lineup of Blacks disappearing over the crest of Laguna's front straight.

Like the two previous Black Series cars — 2006's SLK55 AMG Black Series and 2007's CLK63 AMG Black Series — AMG started this transformation with one of its own, the SL65 AMG. Even though the Black ended up no lightweight at just over 4100 pounds, its twin-turbo V-12 and composite body panels contribute to a weight-to-power ratio of 6.13:1. The front mudguards, apron, and splitter, as well as the hood and trunk lids are made from carbon-fiber-reinforced plastic (CFRP), and AMG trimmed significant weight from above the beltline by replacing the motorized hardtop with a fixed roof that is also made from CFRP. These measures and more take over 500 pounds out of a European-spec SL65 AMG but, because of a few equipment differences, the weight reduction for a U.S.-spec Black Series is only about 250 pounds.

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Ironically, there's a lot more car in this lighter Black Series than in a normal SL65 AMG, thanks to a muscle-popping regimen in the design studio. The rear window and roof — which integrates a rollbar — are both flatter for better aerodynamics. The CFRP rear spoiler automatically deploys 12 cm from the rear deck lid at a speed of about 75 mph. If you're a calibrated type, you'll be interested to hear the spoiler increases "rear-axle power take-off at 200 km/h by 50 kg." For the rest of us, the thing just looks badass. This car has a great butt, with a deep rear apron and carbon-fiber diffuser that — be still my heart — incorporates an active cooling system for the limited-slip differential. New, lightweight forged wheels — 19 inchers up front and 20s out back — and fill the wheel housings to the brim.

My ruminations were interrupted by the sound of our session's lead car growling to life. This specially built, DTM-like SL was driven by Meyer, who learned his chops working at BMW's M division and also racing BMWs. Give him the Nürburgring on a wet day and a car with excessive throttle steer, and he's a happy guy. I'd been told that our first lap would be for "orientation, just to get comfortable with the car," but someone forgot to tell Meyer, who apparently was convinced he was on a qualifying lap. I've driven Laguna a bunch of times, in a variety of cars, but I'd never been dragged into a game of excessive speed so quickly.

It wasn't like I lacked the beans to keep up. Because of noise restrictions, Meyer's special SL had to wear a huge, appallingly phallic silencer on its side exhaust and so was running around with 300 fewer horsepower than I had in the Black. Three hundred! Even so, I couldn't catch him with a air-to-surface missile, so quickly was he out of sight. After a few laps watching him pitch his SL through Laguna's tight corners and down the iconic corkscrew, it was clear to this amateur quack that Meyer is truly deranged.

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Okay, in my defense, I was hampered by the Black's traction systems, which were using every measure at their disposal to maintain the safety demanded for everyday driving. With ESP fully engaged, any instability is quickly balanced by the automatic application of one or more brakes and by a reduction of engine torque. This is not the quick way to get through a corner, as the lack of power and application of brakes is, not surprisingly, a deterrent to speed, putting a huge damper on fun things like oversteer and throttle steer.

I next pressed the ESP button to activate the Sport function, which allows a certain amount of slip angle before the electronics stomp on the fun. Fully depressing the brakes reactivates the ESP, but slight taps to set up the chassis for a corner seemed to have no effect. This mode is the way to go for most weekend racers, because sending the engine's 738 lb-ft of torque (electronically limited!) straight to the rear tires without any intervention is asking for a spin around the dance floor. If you're game enough, and skilled enough, please do hold down the ESP button to turn off common sense completely. I did for half a lap and chose to re-engage the sane world with Sport mode.

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It's still possible to reactivate all of the ESP functions by depressing the brake pedal, and traction logic is active in all three ESP modes, so the AMG boys haven't left drivers completely out on the limb they so enjoy swinging from. If a drive wheel starts to spin, specific automatic brake control intervenes to improve traction, and, working together with the multiple-disc limited-slip differential that has over 40 percent of its locking effect in deceleration, it ensures the engine's massive power is transferred to the road with minimum loss. This also means that fans of smoky burnouts will be disappointed by the Black's civility, but I dare anyone to be let down by a 0 to 60 mph time of 3.8 seconds.

AMG's familiar five-speed Speedshift Plus manumatic handles the transfer of power, but there's so much of it that the gearbox might as well be a two- or three-speed. I never came close to top gear at Laguna despite reaching 130 mph on the front straight, and at normal speeds the transmission is so smooth the shifts are scarcely noticed. Paddles sit just behind the steering wheel for those times when another gear is needed quickly, but there's always plenty of power in regular old "Drive," where the shift lever can be ignored completely, even if you're blowing off a skeptical neighbor's 911.

There are four drive programs: C, S, M1, and M2. Both manual (M) modes hold a chosen gear and will not change up even at full throttle, and M2 has a 20-percent quicker response time than M1. The automatic double clutching on downshifts is cool, and reduces the effects of load alteration on the chassis — which is especially crucial when braking for a corner on the race circuit or for safer driving in wet and icy conditions.

In keeping with the Black's ludicrous power and torque, the powertrain was beefed up along with such components as the clutch discs, gearchange and converter bypass logic, as well as the driveshafts, wheel carriers and bearings, and the spring links on the rear axle.

The new sports chassis features a coil-over suspension that allows adjustable shock damping and ride height, as well as changes to wheel camber for the knowledgeable (and well-heeled) track rat. Both axles have newly developed spring links and thrust, camber, and tension rods, as well as reduced-weight aluminium wheel carriers. Compared with the series-production SL65 AMG, the Black's track is 115-mm wider in front, 103-mm wider in the rear. The steering system received suitable mods, too, with new front-axle kinematics and an 8-percent more direct ratio. The result is a big car that feels nimble through the tighest corners.

It doesn't hurt the handling that 265/35R19s sit on 9.5-inch AMG light alloys up front and 11.5 x 20 light alloys are wrapped by 325/30R20s at the rear. The Sport Maxx GT rubber is supplied by DTM Motor Sports partner Dunlop and delivers outstanding grip, lots of predictability at the limit, and a comfortable ride. Look through the double spokes on the AMG wheels in front, and you'll see vented, perforated brakes with 6-piston fixed calipers and 390 x 36-mm brake discs. In back, 4-piston fixed calipers clamp 360 x 26-mm discs. With enough stopping power for almost every occasion, they held up reasonably well during the lengthy track sessions, smoking slightly after especially spirited runs but also avoiding excessive fade. I would have preferred a shorter brake-pedal travel and quicker response from the calipers on the track, but on the street they were more than adequate.

More than adequate, too, is the V-12's performance. Except for the redesigned twin turbochargers, not much was required to achieve the Black's additional 58 horsepower, as the handbuilt 6.0-liter's innards are plenty stout already. The two turbos are newly configured with a spiral cross-section that's 12 percent larger. Combined with optimized wastegate ducts, they enable higher airflow rates and increased power across the rev band. Cooling of the intake charge and engine has been improved by 30-percent more efficient twin intercoolers, a repositioned radiator, and large vents in the hood. A modified intake duct and new mufflers deliver a distinctive and wondrous acoustic harmony made up of turbo whistle and exhaust boom.

Even though its bodywork and engine are loud statements of high performance, the Black's cockpit is a center of quiet control. Nappa leather, Alcantara, carbon fiber, a new instrument panel, shift lever, and flat-bottomed steering wheel greet the driver, but North American buyers will not be getting the new AMG CFRP-constructed bucket seats because of issues involving the side air bags. Pity, as the race buckets deliver the lateral support demanded by track loads. Even so, the chairs in U.S. models are excellent for cruising or for carving through corners.

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For those daring enough to look away from the road ahead, the Black also offers a wide array of electronic goodies. These include the standard COMAND multimedia center with a new 6.5-inch color screen that combines all the controls for the radio tuner, telephone, CD/DVD changer, Bluetooth interface, drive for SD memory cards, and external audio devices.

I did not operate any of those systems, as I was too busy staying on the pavement while following Meyer's viciously quick lead. Many laps later, I felt quite comfortable sliding the Black through the corners, but it would have taken years of experience behind its wheel to catch Meyer. Really experienced drivers might find the traction controls too intrusive, but I was comforted to know they were waiting to bail me out if I drove beyond my skill level. Even with ESP fully engaged, the Black is one crazy-fast car. Whoever said there is beauty in madness probably just spent a few hours in an SL65 AMG Black Series.

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