2007 Porsche Boxster S

(from Porsche Press Release)  NEW ENGINES FOR THE 2007 PORSCHE® BOXSTER® AND BOXSTER S ADD TO CLASS LEADING DYNAMICS AND REAL-WORLD PRACTICALITY

Porsche’s two-seat roadsters offer unique blend of mid-engined handling in thoroughly useful two-trunk ragtop package.  The biggest news for the 2007 Boxster lineup is new powerplants in the already award-winning drop-tops. The Boxster S receives the 3.4-liter flat-Six engine from the Cayman™S with an identical 295 horsepower rating. The Boxster receives a reworked version of the 2.7-liter Boxer mill rated at 245 horsepower—only 5 less than the original Boxster S.  Both engines are now fitted with Porsche’s VarioCam®Plus variable intake-valve timing and lift system, which broadens the engines’ torque curves, increases fuel economy, and helps reduce emissions. Also new for ’07 on the Boxster lineup is a revised an updated Tiptronic®S automatic transmission, a standard Tire Pressure Monitoring System (TPMS), a reworked positioning of the service tray to improve the shape of the rear trunk, and optional new 19-inch wheels from the 2007 911® Turbo.

New engines for more power in a capable chassis
Providing power for the 2007 Boxster S is the new 3.4-liter “Boxer” six-cylinder engine from the Cayman S. While based on the 3.2-liter engine in the 2006 Porsche Boxster S, this engine wears the cylinder heads and uses the same VarioCam Plus technology as the venerable Porsche 911 Carrera—a combination of adjustable valve timing and variable valve lift on the intake camshaft. VarioCam Plus carefully manages camshaft and valve lift to constantly make adjustments to optimize power output, resulting in 295 horsepower and 251 foot-pounds of torque. This helps propel the ’07 Boxster S from a standing start to 60 miles per hour (96 km/h) in just 5.1 seconds. The Boxster S will reach a top test-track speed of 169 mph (272 km/h). The engine’s efficiency also shows in its emissions, as it qualifies as an LEVII (low-emission category two) vehicle in the United States, and in its fuel economy rating of 20-mpg city and 28-mpg on the highway. In addition to its short stroke and VarioCam Plus technology, the new engine benefits from newly developed crankshaft, main bearings and pistons. The crankshaft in the Boxster S shares dimensions with that in the 911 Carrera and the aluminum crankcase is virtually identical to that used in the Porsche flagship.

Smaller pistons, higher compression ratio
Like the Porsche 911 models, Cayman S, and now the Boxster S, the power unit of the 2007 Boxster also features VarioCam Plus technology. Maximum output of this six-cylinder power unit is 245 bhp, with torque peaking at 201 lb-ft between 4600 and 6000 rpm. The 2.7-liter power unit comes with an even lighter crankshaft and a higher compression ratio than on the Boxster S, with output of 91.2 bhp per liter vs. 87.1. With the standard 5-speed manual transmission, the ’07 Boxster accelerates from a standstill to 60 mph in just 5.8 seconds (0-100 km/h, 6.1 sec.), and has a top test-track speed of 160 mph (258 km/h). Fuel economy is an impressive 23-mpg city, and 32-mpg on the highway with the standard 5-speed manual transmission. In its external dimensions, the 2.7-liter boxer is identical to the 3.4-liter in the Boxster S – but the moving parts within the engine are largely new in design and construction. As in the 3.4-liter power unit, stroke of the 2.7-liter engine is 78 millimeters or 3.07". The reduction in engine displacement, therefore, results from the smaller diameter of the cast pistons down to 85.5 millimeters or 3.37". The 2.7-liter engine features an even lighter crankshaft and the bores in the hollow piston pins are larger than before to save six grams in each pin, giving the engine an even faster, more freer-revving response. Detailed improvements are also to be found in the cylinder head, where an injector bore between the two outlet valves completed after the casting process improves coolant flow to reduce thermal loads at this point, helping reduce the risk of the engine knocking. As a result, the compression ratio has been increased by two-tenths over that of the Boxster S to 11.3:1. With the external dimensions of the two power units remaining geometrically identical, the new 2.7-liter has the same intake manifold as the 3.4-liter engine, incorporating a resonance flap and a double-chamber distributor pipe with a distributor pipe flap further downstream. High torque throughout the entire range of engine speed is ensured by the intake system, with the switch thresholds on both flaps being adjusted to the size of the smaller engine. The distributor pipe (resonance length) and the resonance flap (resonance cross-section) are controlled as a function of engine speed for superior torque throughout the entire speed range. As long as the two flaps are closed, the two rows of cylinders draw in combustion air separately from one another, the engine thus acting as a double three-cylinder. In the lower speed range this effect increases engine torque significantly.

Integrated dry sump lubrication with three oil pumps
As mid-engined sports cars, both Boxster models are designed from the start for a dynamic style of motoring with a high level of lateral acceleration. The most important prerequisite to make this possible, of course, is a safe and reliable supply of oil to the engine. This is guaranteed by integrated dry sump lubrication incorporating two re-delivery pumps extracting oil from the cylinder heads and pumping it into the oil sump. From here, a pressure pump delivers oil to the lubricating points within the engine, the lubricant being cooled by a compact oil/water heat exchanger.

Where’s the dipstickogon;
The integrated dry-sump system is so precise at monitoring oil that the Boxster engines require no dipstick; an electronic monitor measures the oil level and displays the result on the instrument cluster.

Gearing up the Boxster and Boxster S
The 2007 Boxster employs a standard five-speed manual gearbox and can be optioned with the six-speed manual that is standard equipment on the Boxster S. The six-speed manual, like the five-speed manual, has reinforced synchromesh rings on all gears. Multiple synchromesh rings assures quick and easy shifts even with short shifter travel. The five-speed manual features triple synchromesh on first gear and double synchromesh on second. The six-speed has triple synchromesh on first and second gears and double synchromesh on third, fourth, fifth and sixth. As on the 911 Carrera, the synchromesh rings in first and second gear on both Boxster manuals have a wear-resistant carbon coating.

An automatic choice: Tiptronic S
New for 2007 and optional on either the Boxster or Boxster S is the revised and updated Porsche Tiptronic S five-speed automatic transmission, which allows for manual gear changing via fingertip controls located on the crossbar of the steering wheel. For 2007, the Tiptronic S available in the Boxster has been upgraded with new hydraulics and electronics as on the 911 series and Cayman S. This transmission’s refinements are best utilized when combined with the optional Sport Chrono package, which when engaged allows for variable shift patterns, which include more aggressive downshifts, quicker shift times, and the ability to hold gears against the rev limiter.

Variable-ratio steering
The Boxster and Boxster S come with standard variable-ratio rack-and-pinion steering that helps enhance their agility on winding roads while helping maintain stability at higher speeds. When the steering wheel is within 15 degrees of its on-center position, the steering ratio remains similar to that used on the first-generation Boxster. This assures a smooth and calm driving experience, even on rough surfaces. However, when the steering wheel angle exceeds 15 degrees from center, the ratio becomes more direct, reducing lock-to-lock and giving the driver better control on winding roads as well as in slow-speed maneuvers, such as when parallel parking. Even with its wide tires, the Boxster offers a turning circle of only 36.4 feet (11.1 meters).

Standard Tire Pressure Monitoring System
Porsche’s Tire Pressure Monitoring System (TPMS®) is now standard on both Boxster models. Wheel sensors constantly monitor the air pressure in each tire and alert the driver with two warnings. A “gentle” warning in white text appears on the digital display within the tachometer if air pressure drops by more than 2.9 psi but less than 5.8 psi. This warning appears for 10 seconds each time the car is started. A “stern” warning is displayed in red text on the tachometer's digital display if air pressure drops more than 5.8 psi or if pressure is falling by more than 2.9 psi per minute. This warning appears as soon as the respective values are exceeded, whether the vehicle is stationary or moving.

More symmetrical and useful rear trunk
For 2007, all Boxster models have a more symmetrically shaped rear trunk, thanks to the repositioning of the service tray, which allows access to the engine-oil filler neck and coolant expansion tank. The coolant tank is now located inside the engine compartment, allowing both the coolant and oil fill caps to be repositioned behind a flush panel on the forward bulkhead of the rear trunk. This has removed the bulge on the right-hand side of the rear trunk, creating a storage space with similar capacity (4.6 cu. ft./130 l), but with a more symmetrical shape, improving usefulness of the rear trunk.

Multiple wheel/tire combos
The Boxster rides on standard 17-inch wheels and the Boxster S comes standard with 18-inch wheels. Optional on either vehicle are 19-inch rims. Boxster and Boxster S wheels are strong but lightweight, thanks to a flow-forming process. The Boxster comes with wheels that feature a forked, five-spoke design. Wheels are 6.5 inches wide in front and eight inches wide in the rear. All tires are Z-rated radials, 205/55 aspect in front and 235/50 in the rear. The Boxster S rides also rides on forked, five-spoke wheels, though the design is different from the Boxster pattern. The front wheels are eight inches wide and the rears are nine inches wide. Tires are 235/40 aspect in front and 265/40 in the rear. Four 19-inch wheels are available as options, including a new tri-spoke wheel for ’07 from the new 911 Turbo. All are 8-inches wide in front and 9.5-inches wide on the rear axles. The larger wheels enhance vehicle dynamics and also shorten stopping distances.

Spare tire would add unnecessary weight
To save 22 pounds (10 kilograms) per car, and to provide additional room for luggage, the Boxster and Boxster S are not equipped with a spare tire or a jack for changing tires. Instead, the cars have an electrical air compressor and emergency tire sealant. Damage, such as that caused by a nail in the tread, can be temporarily repaired by using the tire sealant and re-inflating the tire. Porsche reminds drivers not to exceed 50 mph (80 km/h) on a tire with a temporary repair and to have the tire replaced or professionally repaired as quickly as possible.

Enhanced braking system
The Boxster and Boxster S are equipped with cross-drilled disc brakes at each wheel. Like all Porsche vehicles, brakes undergo extreme testing both for stopping power, durability and resistance to fading. On the Boxster, front brakes are 11.73 inches (298 mm) in diameter and 0.94 inches (24 mm) thick while the rear brakes are 11.77 inches (299 mm) across and 0.79 inches (20 mm) thick. The more powerful Boxster S gets even larger front brakes: 12.52 inches (318 mm) by 1.1 inches (28 mm) while the rear brakes are 11.77 inches (299 mm) by 0.94 inches (24 mm) thick. Both cars have four-piston aluminum monobloc calipers and anti-lock braking technology. The Boxster and Boxster S use a mechanically driven vacuum pump that supplies pressure to the brake servo instead of a conventional suction jet pump within the engine intake manifold. Driven by the exhaust cam on the right-hand cylinder bank, the pump provides a high and consistent level of power, even in low ambient air pressure or high altitude conditions and during highly dynamic driving conditions under mostly open throttle.

Porsche Ceramic Composite Brakes available
Optional on the Porsche Boxster S are Porsche Ceramic Composite Brakes (PCCB). Because of their exceptional performance in extreme conditions, ceramic composite brakes were developed for use in high-level motorsports competition. Porsche was the first automaker to apply them for road use, where they are standard equipment on vehicles such as the Porsche Carrera GT and Porsche 911 Turbo. Instead of metal, the 13.78-inch (350 mm) brake discs are a ceramic material that provides high and consistent levels of friction during application. They also weigh approximately 50 percent less than metal discs and thus reduce the vehicle’s unsprung mass by 34.4 pounds (15.6 kg). The newest generation of Porsche Ceramic Composite Brakes is even more rigid, yet includes more interior cooling ducts. Fiber reinforcement on the friction surface is increased, significantly enhancing resistance to abrasion under high loads.

Porsche Active Suspension Management available
Porsche introduced PASM — Porsche Active Suspension Management — technology on the 2005 911 Carrera, and this system also is available as an option on the Boxster and Boxster S. PASM provides two suspensions in one: a sporting but comfortable setup for normal use and a very dynamic setup for performance-driving situations. By pressing a button on the center console, the driver can switch from PASM “Normal” to PASM “Sport.” In testing at Germany’s famous Nürburgring racing circuit, a Porsche 911 Carrera equipped with PASM and set in the Sport mode produced lap times an average of five seconds per-lap faster than with the standard suspension setup. But there are advantages to PASM even when left in its normal setting because it automatically adjusts to changes in driving style, gradually becoming firmer in response to greater dynamic forces. The PASM system combines continuously adjustable shock absorbers, a pair of accelerometers — one in the front right damper dome, the other in the left rear — that determine vertical movements of the car’s body, and an electronic control unit that also has access to steering angle, road speed, brake pressure and engine torque figures. This provides optimum damper control for each wheel with active dampers that have a similar structure as standard shocks, providing damping with oil pressure, but also a bypass valve that opens and closes to increase or reduce the oil flow as needed.

Dynamic modules for nearly any driving situation
PASM is equipped with five special software modules—lane change, vertical control, lateral acceleration, brake and load change—to provide optimum settings for many driving conditions: