Porsche Boxster S (2007)

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 Porsche 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 threecylinder. 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 Porsche 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 dipstick?

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

Gearing up the Porsche Boxster and Porsche 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 Porsche 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 sixspeed 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 Porsche Boxster manuals have a wear-resistant carbon coating.

An automatic choice: Tiptronic S

New for 2007 and optional on either the Porsche Boxster or Boxster S is the revised and updated Porsche Tiptronic S fivespeed 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 Porsche 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 Porsche 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 Porsche 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 Porsche 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 Porsche 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 Porsche 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 Porsche Boxster rides on standard 17-inch wheels and the Porsche Boxster S comes standard with 18-inch wheels. Optional on either vehicle are 19-inch rims. Porsche Boxster and Boxster S wheels are strong but lightweight, thanks to a flow-forming process. The Porsche 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 Porsche Boxster S rides also rides on forked, five-spoke wheels, though the design is different from the Porsche 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 Porsche 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 Porsche 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 Porsche 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 Porsche 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 Porsche 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 Porsche 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:

• Lane change module: In response to rapid movements of the steering wheel in a sudden maneuver, the system instantaneously increases damper forces on both axles, reducing any tendency toward sway or rocking.
• Vertical control module: In the normal program, damper forces increase whenever vertical movement of the car's body exceed a threshold, for example, when driving on a bumpy surface. This prevents any risk of the body starting to rock. However, when in the sport program, the system reduces the damping effect to maintain wheel contact with a rough surface, preventing the risk of the car "jumping" around.
• Lateral acceleration module: In the normal program, damping varies through a curve, adjusting with road speed and lateral acceleration.
• Brake module: As soon as the driver applies the brakes, PASM firms damping to reduce body dive, ensuring faster transmission of brake forces to the road. Then, at a certain point in the braking process, the system switches to softer damping, with different forces applied in the front and rear of the car. This ensures better surface contact and shortens stopping distances, even on rough roads.
• Load change module: In all-out acceleration, with the driver lifting off the accelerator while shifting gears, the control maps are adjusted for the front and rear axles. In the normal mode, harder damping is used briefly to prevent too much squat. In the sports mode, a softer damper response is used to improve traction, for example, on a rough road surface.

Porsche Stability Management is standard equipment

All Porsche Boxster and Boxster S models are equipped with enhanced Porsche Stability Management (PSM) as standard equipment. PSM is a computerized system that uses the sensors for ABS (anti-lock braking), ASC (anti-spin control), EDC (engine drag control) and ABD (automatic brake differential) and intervenes to help the driver keep the car on its intended path rather than sliding too far sideways, say in a fast and tight turn.

To provide the driver with more latitude in slower curves, PSM intervenes later when the vehicle is traveling at a rate below 45 miles per hour (70 km/h).

The driver can deactivate the system with a switch and the system stays off until the driver applies the brakes. However, with enhanced PSM, the system does not reactivate until the driver presses firmly on the brakes, reaching the ABS threshold on at least one front wheel. For the enthusiast driver, this change allows more dynamic freedom, including slight use of the brakes in curves.

Sport Chrono Package Plus

Available as an option on the Porsche Boxster and Boxster S is the Sport Chrono Package Plus that allows the driver to engage more aggressively set electronic management system control maps. This feature also includes a separate stopwatch gauge on top of the instrument panel.

By pressing a button on the center console, the driver engages Sports Chrono to take driving dynamics to a standard never before available. The Sports Chrono options provides a more aggressive throttle map for the engine controls, and also effects the engine speed limiter, PSM, PASM and Tiptronic S.

When the Sports telltale light is illuminated on the center portion of the gauge cluster, the driver knows that the E-gas control line has switched to a steeper configuration that puts the Tiptronic S in its manual mode, thus the throttle butterfly responds more quickly to movements of the gas pedal and the driver enjoys even more spontaneous response from the engine. Should the driver keep the accelerator pedal fully depressed without shifting gears, the engine speed limiter in gears 1-5 intervenes far more abruptly than in routine driving. Shifts become less oriented to comfort and the throttle butterfly closes faster when the driver lifts off the accelerator pedal, thus providing a more dynamic driving experience, more similar to the feedback a race driver gets from a car on the track.

The operation and intervention of PSM also changes to provide greater agility. For example, when accelerating out of turn in the Sports mode, higher anti-spin control thresholds allow more slip from the rear wheels. This can result in even faster acceleration because PSM does not intervene as quickly.

Likewise, other PSM thresholds, such as those that control the anti-lock braking system, are raised to a level that allows more dynamic control by the driver before the system intervenes. And the particularly skilled driver retains the option of switching off the PSM system and taking full manual control of the car's dynamic direction.

If so equipped, PASM also switches automatically when needed to a sports program that provides firmer suspension settings, reducing even further any body lean through corners and enhancing contact between the tires and the road surface. However, there are circumstances, such as on wet or snowy roads, in which a "softer" suspension setting can enhance traction and the PASM button can be pushed to put the car in its normal setting even when the sports mode is active.

The "Sport Chrono Plus" feature includes a stopwatch and lap-counting function. So the driver can graphically verify the improved dynamics of the second-generation Porsche Boxster and Porsche Boxster S, the driver can push a stalk attached to the left side of the steering column to record various route segment times, which can be reviewed graphically on the optional Porsche Communications Management (PCM) system screen.

Keeping cool

Clever and effective engineering devised ways to incorporate enhanced cooling for the engine, transmission and brakes. Two large inlets for cooling air characterize the front air dams of the Porsche Boxster and Boxster S. The Boxster has a pair of front radiators, with a third unit added for the Porsche Boxster S. A highly efficient water pump moves more cooling liquid, yet is lighter in weight and allows for the installation of a more compact oil/water heat exchanger.

The under tray manages airflow beneath the cars, effectively gluing them to the roadway. At the same time, flexible "blades" direct air for cooling the transmission. "Spoilers" installed on the front longitudinal suspension arms enhancing brake cooling.

Lighting the way

The Porsche Boxster's headlamps have the traditional Porsche look, but with separate fog lamps that are positioned low and well apart from the car's centerline to better light the way through inclement weather while driving and very dark roads. The headlamps are designed to enhance the driver's lateral illumination. Rear lighting features three separate elements on each side of the car with strong distinction between red and white areas.

First production roadster with door-mounted "head" airbags

All Boxsters are equipped with three-point inertia-reel seat belts with belt-latch tensioners and belt force limiters as well as six airbags. In addition to two-stage frontal airbags, the Porsche Boxster and Boxster S feature the Porsche Side Impact Protection (POSIP) system with a torso-protecting airbag at the outside of the seat backrest and head airbags in the door windowsills.

Two-stage front airbag technology as standard equipment

Both front airbags use an organic-based propellant that not only makes them lighter and more compact, but easier to recycle as well. Designed to accommodate child safety seats, the passenger seat features sensors that automatically switch off the passenger airbag depending on the weight detected. The front airbags are augmented by a side-impact protection system featuring side airbags integrated into the front seats that work in tandem with airbags that deploy upward from their housings in the door windowsills to help protect occupants' heads.

Lightweight convertible top contributes to dynamic capabilities

With a frame made from aluminum and magnesium, the power convertible top on the 2007 Porsche Boxster and 2007 Porsche Boxster S helps lower the cars' center of gravity and thus contributes to their enhanced dynamic capabilities. The canvas roof uses light synthetic fleece fiber for improved noise and heat insulation and has an electrically heated rear glass window. The top is power operated and can be opened or closed even while the car is moving - at speeds up to approximately 40 miles per hour (64 km/h). A wind deflector is available, as well as a removable aluminum hardtop that weighs only 51 pounds (23 kilograms).

Interior provides support and comfort

The interior of Porsche's roadsters provides both comfort for cruising and the support needed for dynamic driving. The dashboard, interior door panels and the sides of the center console are covered in a special durable material while the gearshift lever, steering wheel rim, handbrake lever handle and door handles are covered in leather. On the Porsche Boxster S, the cover on the storage box in the center console and those on the storage pockets in the doors are covered in leather. Aluminum-look trim is used around air vents and on the gearshift lever.

The Porsche Boxster provides a second 12-volt power outlet on the passenger's side of the center console while a pair of cup holders is integrated into the dashboard and remain hidden behind a trim strip when not in use.

Steering columns tilt and telescope to better fit every driver. The tilt feature allows the steering wheel position to move by 1.57 inches (40 mm). Attached to that tilting and telescoping steering column is one of three steering wheels. The standard wheel has a three-spoke design. It is 14.76 inches (375 mm) in diameter and is built around a composite magnesium skeleton that reduces weight by 10 percent compared to the aluminum frame formerly used. The optional sports wheel is just 14.57 inches (370 mm) in diameter with ergonomically contoured grab recesses on the rim to accommodate dynamic driving maneuvers.

Also available in conjunction with the optional Porsche Communication Management system is a multifunction wheel that allows the driver to operate audio, navigation and telephone functions by six function keys built into the steering wheel. The keys are embedded into aluminum-look trim panels. Porsche's Communication Management (PCM) system that can play MP3 encoded CDs through the CD unit.

Available as an option for the PCM system, an electronic logbook feature allows automatic recording of mileage, journey length, date and time as well as the starting point and destination address for any trip. Also optional is an extended navigation module that includes "back-trace" technology so you can find your way back to your starting point even when the roads you travel may not appear on the navigation system map.

Four seating choices

The Porsche roadsters come with four leather-covered seating choices:

• The standard seats can be adjusted in six directions, with power travel for the backrest angle and manual fore-aft and height adjustment.
• Full power seats are adjustable 12 ways and include a pneumatic lumbar support with two inflating air cushions. The memory function on the driver's seat includes the lumbar inflation setting.
• Sports seats are based on the standard seats but provide even more side support for dynamic driving, in the seat and back cushions and also around the shoulder area.
• Adaptive sport seats combine the benefits of full electric adjustment and enhanced lateral support. These seats also allow individual adjustment of the various side supports.

All seats in the Porsche Boxster and Boxster S are mounted as low as possible, helping to lower the center of gravity and enhance driving dynamics. This lower seating position also increases the available headroom when the convertible top covers the passenger compartment. Lightweight technology enables Porsche engineers to develop seats that are strong and stable yet provide taller backrests with thorax-protecting airbags mounted within the seat. Porsche also has developed a patented vibration dampening system for its seats.

Instrument cluster informs the driver

A large tachometer dominates the central spot on a three-gauge instrument cluster. Road speed is presented in both analog and digital formats with rpm, fuel level, coolant temperature, odometer, clock and outside temperature displays providing the driver with important information.

The Porsche Boxster has black face gauges with light gray gauges in the Porsche Boxster S. Using LEDs in white rather than yellow enhances readability of all gauges in low-light conditions.

Additionally, cars equipped with the Sports Chrono system display information in the dot matrix display in the lower third of the rev counter.

An eye-catching center console descends from the center of the instrument panel, just beneath a pair of vertically oriented and oval air outlets. All switchgear, including window controls mounted in the doors, have small "finger strips" that facilitate manipulation of the various control functions.

The Porsche CDR-24 CD radio has a larger control surface for easier use and is illuminated by white LEDs. The system includes two tweeters in the instrument panel with a woofer in each door.

Optional on the Porsche Boxster and standard on the Boxster S is the 180-watt Porsche Sound Package Plus with seven speakers and an external analog amplifier, two tweeters and a mid-range speaker in the instrument panel as well as a subwoofer and mid-range speaker in each door. Also available is a 325-watt Bose Surround Sound system with 11 speakers and a seven-channel digital amplifier.

Porsche Communication Management

Optional on both the Porsche Boxster and Boxster S is the enhanced Porsche Communication Management (PCM) with its DVD based navigation located in the luggage compartment. This allows the CD drive on the PCM to be used exclusively for audio CDs, or MP3 encoded discs. The navigation system features 23 zoom stages from a minimum resolution of 55 yards (50 meters). Its information is displayed on a 5.8-inch color monitor.

Abundant storage space

Among the Porsche Boxster's unique features are two luggage compartments, one trunk at the front of the car and another trunk at the rear. An added benefit of the Porsche Boxster's architecture is that its convertible top system takes up none of the car's available storage area even when the top is down. The front luggage compartment offers 5.3 cubic feet (150 liters). The rear compartment provides 4.6 cubic feet (130 liters).

Impressive list of options

The long list of options available for the Porsche Boxster or Boxster S includes Bi-Xenon headlamps and Park Assist that uses ultrasound to measure the distance to the nearest obstacle and warns the driver as needed.

Low ownership costs

Helping to reduce the ownership costs of the 2007 Porsche Boxster and 2007 Porsche Boxster S are the need to change oil only every 20,000 miles (30,000 km) and to perform routine service only every 40,000 miles (60,000 km).