Source: Car and Driver
Full Article: 2017 Porsche 718 Boxster / Boxster S First Ride: Excellence, Blown
Having escaped Michigan in February for the south of France to sample the 2017 Porsche 718 Boxster convertible, we arrive to find one of our two expectations for the trip dashed. It’s drizzling and 50 degrees at Michelin’s test track on the outskirts of Marseille, where we’ve gathered to experience some early prototypes of the newly turbocharged, four-cylinder Boxster and Boxster S. Everything else is going swimmingly, no pun intended. Buckled into the 718 Boxster S’s passenger seat, I’m fighting against lateral g’s to hold myself upright and scribble notes as the car blasts into a banked, high-speed curve. Michael, a Porsche development hotshoe, jerks the wheel back to center as we hit the straightaway portion of Michelin’s small high-speed oval. My pen uncontrollably draws a diagonal slash across the notepad, graphing in real time the inverse relationship between grip and penmanship.
Michael’s typical day involves repeatedly guiding 911 Turbos through sub-eight-minute laps of the Nürburgring Nordschleife for endurance testing, and in this capacity he seems calm, nay, bored as he mentions how his 911 Turbo ’Ring ride donated its quicker steering gear to the new Boxster. “See?” Without slowing, we zig and zag across the straightway, my notepad a mess. “The back end is more stable, too,” he offers, referencing the half-inch-wider rear wheels and an engine-cradle-stiffening steel reinforcement.
Engines of Change
Not being in the driver’s seat, it’s difficult to confirm the changes’ efficacy. The back end feels stickier, a prerequisite for integrating the snappier steering gear without sacrificing stability, but then grip and poise are two things the outgoing Boxster already had in spades. A dearth of major chassis changes leave few doubts in our minds that it is as good to drive, if not better, than before. Every 718 employs new 13.0-inch front brakes. The Boxster borrows the outgoing Boxster S’s pieces, and the new Boxster S cribs its slightly thicker rotors (1.3 versus 1.1 inches) from the 911 Carrera. All Boxsters wear new (albeit identical-looking) body panels save for the hood, trunk lid, and windshield frame. It’s essentially a heavy refresh of the third-generation Boxster, with the biggest changes taking place just ahead of the Boxster duo’s rear wheels: turbocharged flat-four engines displacing either 2.0 or 2.5 liters. We’ve been eager to explore how they measure up against their predecessors’ excellent 2.7- and 3.4-liter naturally aspirated flat-sixes.
Derived from the 2017 911 Carrera’s twin-turbocharged 3.0-liter flat-six, the Boxster’s turbocharged flat-fours are very nearly the same minus two cylinders. The only differences between the fours are a larger bore and a larger BorgWarner turbocharger featuring variable turbine geometry (VTG) technology for the S’s 2.5-liter. VTG helps combat turbo lag at lower engine speeds without sacrificing turbocharger size (and top-end power), by using adjustable vanes at the turbine’s inlet to direct exhaust-gas flow like air from the neck of a balloon. The vanes aim exhaust flow at the turbine wheel’s periphery at low rpm to help build boost. Then, at high rpm when ample boost exists, the vanes direct flow toward the center of the turbine wheel to minimize back pressure.
VTG, another donation from the 911 Turbo (and notably absent in the new 911), imbues the Boxster S with sharper-seeming responses than the regular Boxster. The 2.5’s larger turbo runs up to 16 psi of boost, giving the 350-hp Boxster S a substantial 50 horsepower and 29 lb-ft torque advantage over the 2.0-liter car, whose smaller turbo nonetheless offers up to 20 psi of pressure. Both engines produce peak torque below 2000 rpm—280 lb-ft at 1950 rpm for the 2.0-liter and 309 at 1900 for the 2.5, and in each case the full twist is available through 4500 rpm before gently tapering off. Peak horsepower arrives at 6500 rpm for both engines, which rev to 7500 rpm.
The engines’ variances are surprisingly subtle and only detectable at the ragged edges of the powerband. Off the line, the 350-hp 2.5-liter shoves a little harder, particularly when our driver activates launch control (Porsche only stocked Boxsters with PDK dual-clutch automatics for our ride), and chases the redline with more zeal. In the midrange, the two are remarkably similar, and for perhaps the first time in the Boxster’s existence, the base engine appears sufficient and torquey. Clever electronic programming will keep either engine’s throttle open—while cutting fuel flow and closing the turbo’s wastegate—when lifting sharply off the gas pedal to pump air through the turbo to keep it spinning, ensuring snappy response when getting back onto the gas. Either 718 can be equipped with Porsche’s Sport Chrono package, which now includes a drive-mode switch on the steering wheel for cycling among Normal, Sport, and Sport Plus settings. A “Sport Response” button on the drive-mode dial calls up the powertrain’s Sport Plus calibration for 20 seconds to facilitate, say, an aggressive passing maneuver, but it doesn’t add any output or activate an overboost function.
It’s not surprising that the 718s feel livelier than outgoing Boxsters—the 2.0-liter is 35 horsepower and 74 lb-ft stronger than the outgoing 2.7-liter six, and the 2.5-liter is more potent than the old Boxster S’s 3.4-liter six by 35 ponies and 43 lb-ft. Porsche says the 718 Boxster will reach 60 mph in as little as 4.5 seconds, or 0.7 second quicker than the old car. The 718 Boxster S is said to reach the same speed in just 4.0 seconds flat, a half-second improvement. (Both cars are slightly slower without the PDK and Sport Chrono options.) Objective performance improvements are expected, and what surprises us is how the new engines don’t round off the Boxster’s sharp edge. Like the turbocharged six in the new 911 Carrera models, the 718’s fours are close to lag-free and only a hair less responsive than the non-turbo sixes they replace. They’re also smooth for four-pot engines, thanks to inherent balance and standard vacuum-activated engine mounts that loosen at idle and gradually stiffen as speeds increase for more connected driveline sensations. Whether by miracle or magic, neither 718 sounds like a hotted-up Subaru, both emitting a noise that’s similar to the 911 flat-six’s mechanical orchestra, only with the string section removed. Down an octave or two, the sound is purposeful and raspy—more so with the optional dual-mode sports exhaust.
Right, Not Down
Porsche is adamant that the smaller, four-cylinder Boxster engines represent more than mere “downsizing” for the sake of it. The company instead prefers the term “right-sizing,” noting that downsizing taken too far can have negative effects on output and fuel economy. Besides fomenting disappointment, over-downsized, overworked turbo engines can negate the fuel-economy benefits of going turbo in the first place. With carryover gearing in the PDK transmission (in conjunction with a slightly taller 3.62:1 final-drive ratio), and the marginally taller gearing from the old Boxster S’s manual transmission working through the same 3.89:1 final-drive in stick-shift models, the 718 is expected to consume 14 percent less fuel. The PDK can even slip its two clutches to create “virtual gears,” or ratio mixes between two actual gears at certain vehicle speeds and low engine load to maximize efficiency without relying on a higher gear at the expense of engine lugging and low-rpm vibrations.
All of this bears out on the track, where the 718 is a happy scamp trundling at 45 mph or shrieking along in red-mist mode. With our high-speed oval time up, Michael steers toward a wet skidpad to demonstrate the new PSM Sport stability-control setting, which splits the difference between full-on stability control and none at all by allowing larger slip angles and the ability to hold decent drift angles while retaining an electronic safety net. Our butt dynamometers and finely tuned ears satisfied by the new engines, we settle in for a fun ride. As the Boxster pirouettes around, displaying its penchant for gentle and predictable transitions from understeer to oversteer, the 10Best Cars–winning sports car’s dynamic excellence appears safe, unencumbered by forced induction. Even so, proper evaluation of the effects of the car’s engine and chassis updates (larger-diameter dampers, 0.4-inch-lower PASM adaptive sports suspension, and quicker steering)—not to mention the taking of legible notes—must wait for our first drive.