911 Carrera 4S- the Method Man to my Old Dirty Bastard

The great car journo Dan Pund once called Porsche "the Taco Bell of automakers." He was referring to the way the brand uses a few ingredients to create a variety of items — the same fundamental engines, transmissions, and chassis go into the Boxster, the Cayman, the 911, and the 911 Turbo Bellgrande. The new 911 Carrera 4 and Carrera 4S, on sale this October, are no different: They use the basic shell of the 2009 997.5 and lay in a caulk-gun squirt of all-wheel drive from the 997 Turbo.

We reported on the revised 911, with its direct injection engines and PDK dual-clutch manual transmission, last month; you can read Kurt Braun's masterly shakedown of that car here. And even if the RWD and AWD 911s have many, many things in common, we weren't going to pass up Porsche's invitation to see Berlin from the wheel of the new Carrera 4. I loved that band in the '80s, and still have some of their awesome songs on cassette.

There are a few cosmetic changes that give away the C4s. Each is 1.73 inches wider than the C2s at the rear, where an old-school reflector band runs between the new LED taillights. Also, black trim inserts on the rear let you know that a C4, and not a mere two-wheel-drive Carrera, just passed you. If you were to put the car on a lift, you'd see two NACA ducts on the undertray in front of the back wheels, just as on a 911 Turbo — Porsche is putting them on all current AWD models to increase rear braking ventilation.

But it is the Turbo's Porsche Traction Management (PTM) system that significantly expands the Carrera 4's performance envelope. Unlike the viscous clutch that handled torque-apportioning duties in the 996 Turbo and the outgoing C4, PTM is built around an electromagnetic multi-plate unit. In the old AWD system, any differential in axle speed would activate the viscous coupling, providing a maximum torque transfer of 30 percent to the front wheels. Here, the multi-plate clutch takes inputs from all kinds of sensors — steering-wheel angle, yaw, longitudinal acceleration, wheel speed — drives them through a control unit, which tells an annular magnet to act upon a small mechanical booster, which in turn directs the eight sets of friction plates in the main clutch. All this happens in a maximum of 100 milliseconds, and the system can direct 100 percent of the car's torque to either its front or rear axle.

Porsche's rationale for this arrangement is two-fold: 1) It offers better traction on low-friction surfaces, such as steep, snowy driveways, and 2) it delivers better driving dynamics. PTM is able to shift whatever amount of moment you need, wherever and whenever you need it. In full-on cornering, the system sends all engine torque to the rear (where an LSD manages lateral flow), so that the front wheels can devote their full attention to cornering. If, while in that corner, you induce a large amount of understeer, the car sends the appropriate dose of power rearward to neutralize slip angles. Similarly, if you've cast the tail askew, PTM directs some torque to the front. How much torque is dependent on axle load — in steady-state cornering, for example, the distribution would be something like 40/60 front/rear. And don't worry, would-be drifters of your fathers' cars: The Porsche Stability Management system offers buttons to vary the degrees of yaw intervention, ranging from a bit of slip to fully disengaged. With everything off, this thing is as ass-happy as Seymour Butts.

We drove the Carrera 4S (the one with the always-powerful, always-thrumming, 385-hp, 3.8-liter motor) on the roads north of Berlin. Apparently, the Communist regime that fell two decades ago wasn't too concerned about road maintenance. Even with the notoriously anal Germans tending to them, these narrow lanes are still crappy, which says a lot about their original decrepitude. Also, there aren't many Kommie Karz around here anymore, although some comrade-bicyclists are still in action. Many of them travel these roads as families, and put the weakest among them at the front of the line. With each group we passed, the configurations got increasingly absurd — one kid's bike was laden with luggage; there was a girl of 12 or so riding on her dad's front handlebars; there was a pyramid of babies on a unicycle.

And, as mentioned, the roads were war-torn and tank-battered and would have rattled the fender badges off a Ferrari. But the Porsche just soaked it all up, as Porsches have been doing since time immemorial. Even the cabriolet exhibited no cowl shake. Stunningly, the PASM active suspension kept the car from bobbing up and down, which has long been the major ride criticism of these bottom-heavy cars. And though the PTM system adds 86 pounds to the base 911, it does not dull the car's reflexes or adversely affect its acceleration times. All the weight is set low, so the C4 still delivers the feel-good steering, bodacious stopping power, and spectacular roll control that have characterized 911s forever.

Our route took us through canopied roads to a disused Russian air base, now a Michelin Driving Center. We gathered in an old MiG hangar — a grass-topped, concrete Quonset hut made from giant, pre-stressed ribs, bolted together at ten-foot intervals. Remind me again why we were so worried about these people's nuclear capability?

Porsche set up a few exercises for us at Michelin, the coolest of which was a "wet-handling" course. It comprised a dozen technical turns on painted asphalt with a mu rating somewhere around rainy. I revved out the 3.8-liter flat-six until its hum calcified to a wail, and purposely cranked it hard into the first left-hander. The tail instantly swung wide, and then, faster than could even register, the front wheels pulled the car tautly back into line. I tried the same technique on the next corner, going in way too hot and turning in way too late. Here the car subtly and gradually dialed out the understeer itself. The feedback curves on this system are so gentle that the car never seems to be wresting control away from you; sometimes it's hard even to feel it working. And trust me, it was working double overtime. I couldn't believe how brutally it attacked a slippery surface, and how utterly fail-safe it felt.

On the second lap, it took all my willpower not to keep driving like a sadist, even though the C4S seemed to enjoy the flogging. Flowing the car into turns and squeezing on the throttle, it still trimmed out whatever over-exuberance of line it detected. The weird thing was, it didn't kill the fun. It made it more fun, communicating its corrections with economy and clarity.

The irony here is that, for all of Porsche's Taco Bell–ish modularity, the C4 is amazingly coherent. It's not just a sloppy assemblage of parts. This is mainly because, after 45 years, Porsche knows what a 911 should be. But it also may be the result of the small, interdisciplinary teams working on these cars. Everyone at Porsche seems to have two or three jobs: The body-in-white guy was also our lead driving instructor. The chassis guru gave me chapter-and-verse on the PDK transmission. These guys don't work in a vacuum; they know how every piece impacts the whole. That said, I'd still like to end this story with a good chalupa joke. Anyone know one?