Porsche 911 Turbo
The 2007 911 Turbo may be unmatched in its breadth of performance. Few machines can so easily warp our perception of what is possible from a state-of-the-art performance car, and yet so ably serve as a practical and comfortable conveyance for every-day driving. The new Porsche 911 Turbo features a revolutionary 480-horsepower, twin-turbocharged, 3.6-liter boxer engine with the world’s first gasoline-engine application of variable turbine geometry (VTG), a redesigned all-wheel-drive system, and evolutionary styling.
The new 911 Turbo’s engine produces 480 hp at 6,000 rpm, 60 bhp more than its predecessor, raising specific output of the 3.6-liter boxer-Six to an all-time high of 133 bhp per liter. More notable is the engine’s torque curve, which has been bolstered and broadened by the variable turbine geometry system. Peak torque rises to 457 lb-ft (previously 415 lb-ft), but that peak now spans an extended rpm range from 1,950 to 5,000 rpm, compared to 2,700--4,600 rpm in the previous 911 Turbo. Additionally, a function in the optional Sport Chrono Package allows a 10-second, mid-rpm-range ‘overboost’, temporarily increasing turbo boost under full throttle by 2.9 psi, and swelling peak torque to 502 lb-ft.
A 911 Turbo equipped with the optional 5-speed Tiptronic S automatic transmission requires only 3.4 seconds to sprint from 0 to 60 mph. Equipped with the standard six-speed manual transmission, the new 911 Turbo reaches the same 60 mph mark in 3.7 seconds. With either gearbox, the top track speed of the new 911 Turbo is 193 mph.
Much of the 911 Turbo’s improved performance can be attributed to the variable turbine geometry system, the first such system available on a turbocharged gasoline engine. The heart of the technology is adjustable guide blades, which can vary in angle to most effectively guide engine exhaust flow onto the turbocharger’s impeller wheel. The result is a system that provides the advantages of both a small and large turbocharger, improving flexibility and acceleration, particularly at low engine speeds.
To transfer this power to the road, the new 911 Turbo features a redesigned all-wheel-drive system, with an electronically controlled multi-disc clutch replacing the previous model’s viscous clutch. Porsche Traction Management (PTM) allows variable power distribution fore and aft, and depending on conditions, the system’s electronics constantly determine optimal torque distribution to ensure ideal traction. In use, PTM provides exceptional agility on winding roads, outstanding traction in inclement conditions, and impressive active safety even at higher speeds. Though powerful, the 911 Turbo’s PTM setup is one of the lightest all-wheel-drive systems on the market.
The new 911 Turbo’s accelerative performance is duly tempered by its brake system, which is comprised of six-piston monobloc calipers up front, and four-piston monobloc calipers at the rear. Brake disc diameter at all four corners has been increased 20 mm, to 350 mm (13.78 in.). Optional is Porsche’s Ceramic Composite Brake system (PCCB). In addition to the exotic pad and rotor material, the PCCB option provides an increased front disc diameter (380 mm /14.96 in.), absolute corrosion resistance, improved fade stability, and a 37-pound unsprung-weight savings versus the standard brake system.
Styling changes made to the new 911 Turbo are evolutionary. The modified front end features tautly drawn cooling air inlets, widely spaced and deep-set fog lights, and new LED indicators situated in the lateral air inlets. From the rear, the Turbo takes on a more powerful stance thanks to a tail 22 mm (0.9-in.) wider than that of the previous model. The redesigned wing spoiler has been aligned to the wider profile, and slopes downward slightly at each end to nestle the rear fender’s contours. The lateral air inlets behind the doors have also been redrawn, and together with the new air ducts, afford a more efficient supply of cooling air to the intercoolers.
You already know all about the Cabrio's twin-turbocharged 480-hp, 3.6-liter power plant, since it's unchanged from the coupe. Headlines include variable-geometry turbo whiz-bangery, which generates quicker boost response by varying the velocity of the exhaust gas reaching the turbines.
The result? Torque production responds to the position of your right foot with commendable linearity. Mat the throttle and there's only the tiniest pause before the Turbo's formidable reservoir of torque is channeled forth through all four wheels, hurling the car forward effortlessly. The Turbo engine might not have the urgent yowl of the 911 GT3's normally aspirated engine, but there's still the unmistakable flat-6 wail and an intake whoosh that the alfresco Cabrio makes even more noticeable.
As expected, this thing is deceptively rapid. There's 457 lb-ft of torque delivered between 1,950 and 5,000 rpm in a curve that's as flat as week-old hefeweizen. It might have put on a few pounds, but the Cabriolet nips at the heels of the Turbo coupe when it comes to speed.
Porsche claims the Cabrio will cross the line at 100 kph (62 mph) in 4.0 seconds and reach 124 mph in 12.8 seconds with the row-it-yourself six-speed manual transmission. The optional $3,420 five-speed Tiptronic S autobox betters these numbers by two-tenths since it allows you to brake-torque the car at the starting line to build turbo boost for a quicker launch.
It's hard to imagine any Cabriolet owner doing such a thing, however. Between the folding roof and more willowy chassis, the Cabriolet works best as a relaxed high-speed cruiser. There are other Porsche 911 models in which to play racer.
As in the 911 Turbo coupe, the Turbo Cabriolet offers more urge if you want it. The optional $1,920 Sport Chrono Package provides a 10-second overboost function to lift torque to 501 lb-ft between 2,100 and 4,000 rpm. Normal boost pressure of 14.5 psi is raised to 17.4 psi during this overboost period, and we're told that the transmission's ability to shed heat dictates the limit of 10 seconds.
