Published
on 1
May 2012
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All rights reserved.
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People say if there is
only one sports car you must drive in a lifetime, it will be the 911.
Since 1963, the iconic Porsche has always been the standard of
daily-use sports cars. It is not necessarily the fastest or the most
beautiful, but few rivals can combine driving thrills and everyday
usability like it. Even fewer can be as characterful. This unique
character comes from the rear-engined layout and six-cylinder boxer
engine, which dictate its shape, its sound and the way it corners.
Evolution or
Revolution?
For nearly 50 years, Weissach strived to preserve this character while
meeting new requirements for performance, drivability, comfort and
safety. Most of the time it took an evolutionary approach – such as the
cases for the first 25 years and the outgoing 997. Sometimes it needed
a small mutation, such as 964
and 993, to keep it at the
forefront. There was only one time when the 911 ran out of potential
for further development and necessitated a full makeover. That was the 996. The 996 was the turning point of 911's
history. It introduced an all-new chassis, modern aerodynamics and a
water-cooled 24-valve engine so to wave goodbye to the classical era
and say hello to the new world. Its track record became the template
for the latest 991.
As early as 2007, Porsche realized that it could no longer continue the
evolutionary approach on the next 911. Audi R8 had shown it the
strongest ever threats, and the mightily quick Nissan GT-R was just
around the corner – having already set many eye-popping lap times at
Nurburgring. To maintain its leadership the 911 should take another
giant leap like the 996. Therefore, project 998 was kickstarted as a
clean-sheet development program. In order to deceive parts suppliers
who might leak information to its rivals, the project was renamed to
991 later on so to confuse with the next generation Boxster or Cayman.
This explains why the 991 breaks away from the tradition of using
incremental numbers for its code name.
Chassis and Body
The chassis of 991 is all-new. It has a more modern proportion, i.e.
faster windscreen and fastback angles, shorter overhangs, slightly
lower and a wheelbase boosted by 100 mm to 2450 mm – that is only the
third wheelbase extension in its entire history (the first and second
happened in 1969 and 1998 respectively). It also sports a wider front
track to improve handling (up 46 mm on Carrera and 52 mm on Carrera S).
Despite of the extra dimensions, the new car is 30-40 kg lighter than
the outgoing 997, thanks to an aluminum-steel hybrid construction.
Porsche did not follow Ferrari or Audi to employ
spaceframe chassis made entirely of aluminum, because that would have
thickened the pillars and door sills thus hamper cabin space and ease
of entry (remark: aluminum takes larger section than steel to achieve
the same stiffness). Instead, the 991 uses super-high-strength steel,
baron steel and multiphase steel at locations where stiffness matter
most, whereas aluminum is used for the floorpan, roof, door skins,
bonnet, engine lid, luggage compartment, front crash structure and rear
fenders. They comprise
45 percent of the body shell. Besides, the dashboard mounting beam is
made of magnesium. The new chassis is 20-25 percent torsionally stiffer
than the old one.
The new shape is the work of chief designer Michael Mauer. Since
joining Porsche in 2004, this is the first time Mauer is given the
necessary freedom
to reshape the iconic Porsche. The new car has a sleeker, more modern
profile, yet it still looks every bit a true 911. Its faster rear
window leads to a higher tail, which can no longer be called
"ducktail". Details at the rear end is further refined. The slim
taillights and the way they meet the recessed rear spoiler and rear
quarter panels show high level of finishing. Overall, the 991 has a
polished, high-quality feel for which its predecessors could only
dream. This distances it from cheaper rivals like Lotus and Nissan.
The new body retains a drag coefficient of 0.29, but aerodynamic lift
has been reduced to nearly zero, thanks in part to the raised tail. The
rear spoiler no longer sits between the taillights, thus it can get
wider and more effective. As
before, it normally recesses onto the tail and rises at
higher speed.
Suspension, Steering
and
Electronic aids
Suspensions continue to rely on MacPherson struts up front and
multi-links at the rear, but their geometry have been revised to take
advantage of the wider front track and slightly better weight
distribution. As before, PASM provides adaptive damping. A few
technologies are new to the car:
- Dynamic engine mounts:
taken from GT3 and Turbo, it uses magnetorheological fluid to alter the
stiffness of engine mounts. In normal driving, the engine mounts are
set soft to reduce NVH. When computer senses the car is being driven
hard, it automatically stiffens the engine mounts to limit weight
transfer, hence improving body control.
- PTV (Porsche Torque
Vectoring): a brake-actuated torque vectoring system. When the
car is running into understeer, it applies soft braking to inside rear
wheel, driving more power to the outside wheel and eliminating
understeer. (Note: apart from PTV, the 991 has limited slip
differential equipped as standard. Cars with manual gearbox uses
mechanical type LSD, while PDK mates with electronic type.)
- PDCC (Porsche Dynamic
Chassis Control): an active anti-roll system first used on
Cayenne SUV. It uses a hydraulic motor to swivel the two halfs of
anti-roll bars either in the same direction (to harden the suspension)
or in opposite direction (to soften the suspension), so to alter the
resistance to body roll. Walter Rohl recommended to opt for this
feature if you want to optimize lap time.
However, the most controversial change must be the ZF electromechanical
power
steering, taking place of traditional hydraulic power steering. It uses
a rack-mounted motor and complicated control logic to resist the
faults of similar systems. Porsche
claims it enhances efficiency and precision without compromising feel.
Is it true? We shall see soon.
Engines,
Transmissions and
Performance
Compare with the chassis, changes to the flat-six engines are
relatively subtle. Their basic architecture remains, as are vital
mechanisms like VarioCam Plus, resonance-type variable intake system
and direct fuel injection. An efficiency enhancement program added
on-demand oil/water pumps, automatic stop-start, regenerative
alternator and a coasting function on PDK-equipped cars. Porsche claims
fuel economy is reduced by 16 percent.
The ZF-built 7-speed PDK transmission is carried over. Now it is joined
with a manual cousin. The new 7-speed manual is derived from the PDK
and shares a third of its components. The top gear is reserved for
override to save fuel.
As before, there are two versions of regular 911s – Carrera and Carrera
S. They can be distinguished from the number of tailpipes, i.e. twin
for Carrera and quad for Carrera S.
The Carrera has its engine downsized from 3.6 to 3.4 liters in order to
boost economy and further space itself from the S. This is also the
first capacity reduction since 996. Despite that, engineers still
managed to find another 5 horsepower at the top end, resulting in 350
hp at 7400 rpm. Maximum torque is kept at 288 pound-foot, although the
smaller motor takes higher rev to reach that level.
The Carrera S motor remains at 3.8 liters. Thanks to a lower
restriction intake and exhaust system, new air-flow sensors and fuel
injectors, it produces a full 400 horsepower at 7400 rpm, up from 385
hp at 6500 rpm. Max torque increases by 14 lbft and maximum rev is
lifted by 500 rpm to 7800 rpm. As expected, performance is startling.
If you opt for PDK gearbox and Sport Chrono pack (with launch control),
the Carrera S can sprint from 0-60 mph in merely 3.9 seconds, yet that
figure is on the conservative side. Flat out, the car can top 188 mph.
More telling, Porsche said the 991 Carrera S lapped Nurburgring
Nordschleife in 7:40, 14 seconds clear of its predecessor. That puts it
on the same ground as the Turbo and GT3 3.8 !
On the Road
Now let's get on board. The cabin looks vastly different from 996 and
997. First of all, it gets wider, affording considerably more
shoulder room. The driver seat also gets more legroom and
headroom, so even tall guys will feel comfortable sitting all day. No
so good are the rear seats, which remain to be strictly dog seats. Once
sat on
the driver seat, you will find you are separated further apart from the
passenger by a Panamera-style center console.
Its aluminum accents and tactile switch gears feel expensive. Actually,
the whole cabin is now made of higher quality standards so that
it finally looks a match for the price tag. Meanwhile, it keeps the
strengths of the old 911 cabin, such as a superb driving position,
excellent
visibility and a traditional 5-dial instrument. One of the dials has
been converted to an LCD information display.
Both flat-six engines are creamy smooth and extremely free-revving.
Naturally, the 3.4-liter motor could feel a little sleepy at low rpm,
but it gathers rev quickly, becomes strong from 4500 rpm and even
harder beyond 6000 rpm. The 3.8-liter motor feels significantly more
potent. It pulls strongly from 3500 rpm, gets a second boost at 5000
rpm and becomes truly explosive from 6500 rpm to 7800 rpm cut-out, by
the time its metallic hollow howl is overlaid with racing-engine-like
pops and crackles on the overrun. No other six-cylinder engines could
sound so special! The PDK gearshift is crisper than before, edging
closer to the territory of Nissan GT-R but overwhelms it with
smoothness. The world's first 7-speed manual box is less good – not bad
actually, but its gearshift is just not as slick as the outgoing
6-speeder.
In normal driving, the 991 is way more refined than 997. The new cabin
is so much better isolated from noises so that it needs a sound
symposer to conduct the engine noise into the cabin. At cruising speed,
the engine is pretty much muted. The annoying tire noise that bothered
911 for generations is largely reduced. The highly rigid,
long-wheelbase chassis and reworked suspension also deliver impressive
running refinement. Road imperfections are nicely damped and filtered,
resulting in a ride suppleness and quietness matching the best grand
tourers. Yes, its combination of GT comfort and sports car dynamics is
perhaps the biggest achievement.
Speaking of sports car dynamics, the 991 chassis has really lifted the
game. Drive as hard as you can on B-roads, you will find it corners
more like a mid-engined machine. It shows beautiful poise in cornering.
Brake dive and squat under all-out acceleration are significantly
reduced. Even though it still displays more vertical movements than the
best balanced sports cars, those movements rarely hurt its steering or
stability. You can carry huge speed into corners, abandoning the
old-school "slow in, fast out" technique that older generations 911
drivers recommended, because the nose of 991 resists understeer so much
better. Mid-corner adjustment with opposite lock and burst of throttle
becomes a basic instinct, so easy to induce and so easy to catch. That
is to say, the 991 is sharper and more confidence inspiring to drive.
Not everybody loves the electromechanical power steering though. This
is because it has eliminated the tactile information about surface
textures when it is on the straight ahead position – what else can you
expect? EPS saves energy because it does nothing on straight ahead!
Hardcore drivers prefer those kickbacks and vibration in the helm to
let them feel "engaged". However, such information is actually useless.
What matters is the feel when the wheel is steered beyond the straight
ahead, and this is what the ZF EPS excels. It provides all the messages
you need when you get into corners, and frees you from tiresome white
noises on highway. Moreover, its response, precision and weighting are
beyond criticisms. You will love its new-found lightness at cruising
speed and linear weight-up at turns. Sooner or later purists will agree
its superiority over the traditional hydraulic rack.
Against Rivals
The 991 has raised the game for its rivals to catch up. I can't think
of any cars that serve the dual-role of GT and sports car as
good as this one. Audi R8 used to be very strong in this respect, but
now it is eclipsed by the Porsche in both worlds.
Nissan GT-R should be harder to beat. It is decisively faster in both
straight line and the real world. It is roomier and cheaper too.
However, the Porsche feels sharper and more communicative in most
areas, let it be engine, chassis and most major controls. Being over
300 kg lighter, it stops better and feels more agile. Its ride is far
more comfortable and quiet. Its drivetrain has far less NVH. Its cabin
and exterior look are in a complete different class. In other words, it
trades headline numbers for quality. If you are still not convinced,
wait for the 991 Turbo.
The only rival might beat the 991 for pure driving pleasure is Lotus
Evora. It gets the best steering in the road car world and a highly
interactive chassis. Nevertheless, the rest of the car is just not up
to the class standard, let alone the level of 991.
The last rival is an in-house one – 997 GT3 RS 4.0. Yes, it is another
level for driving thrills, but isn't it too hardcore for everyday use?
Especially the deafening noise?
So let us congratulate the new 911 for
getting back to the top of the world! It shows that even after 50 years
there is still plenty of life for a rear-engined, flat-six machine!
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Verdict:  |
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