Racing Pedigree The
history of 911 GT3 can be traced back to the 2.7 RS of 1973. The
lightweight and sport-tuned version of 911won Porsche a lot of glory on
race tracks and gave the keenest drivers the highest driving
satisfaction on roads. Among all the road-going 911s, the Renn Sport
delivered the closest experience to racing car, one that demanded
superior driving skill but also rewarded good drivers with incomparable
feedback. Naturally, it became the most admired 911 in history. After the mighty 2.7 RS, we had 3.0 RS (1974), 964 RS (1992), 964 RS 3.8 (1993) and 996 RS (1995) to follow this racing pedigree. In 1999, the Renn Sport label gave way to GT3 - now RS became a striped out version of GT3. The new car was so named because Porsche would race it in FIA's newly established GT3 category. The first GT3 stunned the world with its speed and handling. It employed a 3.6-litre boxer engine developed directly from the GT1 race car instead of the road-going 911. Lightweight pistons and titanium connecting rods resulted in amazing rev and punch, while lightweight body resulted in a power-to-weight ratio even higher than contemporary 911 Turbo ! its sport-tuned suspensions delivered the sharpest handling. GT3 won the heart of hardcore Porsche drivers as well as the top spot in AutoZine’s rating page. In 2003, Porsche updated the GT3 to the second generation – let me call it “Series 2” because it was still based on the 996 architecture. This time the changes were subtle – stiffer suspensions, higher rev and slightly more power from the same engine. It remained the most effective driver’s car in the world, but obviously the next generation will need to take a bigger step. 997 GT3 So, this is what we are waiting for – the 997 GT3. In UK, it is priced at £80,000, sandwiching between the £66,000 Carrera S and the £93,000 new Turbo. Once you have read through this report, you will see it is a great bargain. Once again, the GT3 targets at the most demanding hardcore drivers, even more so than the Carrera S and Turbo. Although the new Turbo might be a little quicker in straight line, the lighter rear-drive GT3 is supposed to be quicker on track for skillful drivers. For those who participate club racing, Porsche also offers a Clubsport version including a roll cage, carbon-fiber bucket seats, racing harnesses and fire extinguisher.  At the
first glance, you could be both excited and disappointed by the new
design. Excited
because it got some really serious aerodynamic kits, such as the deep
air dam, 5 aggressive intakes at the front bumper, four hot air outlets
at the rear bumper, a double-plane rear spoiler and a unique
centrally-mounted exhaust pipe. All these sounds like a track car. On
the negative side, these function-oriented tweaks hurt the coherent
shape characterizing all 911s and make it more like the work of tuners.
Personally, I still prefer the original 1999 GT3, whose design hit the
right balance between pureness and sportiness.Open the doors, the cockpit must be familiar to all 997 owners, even most luxury equipments have been retained, so this is no longer a striped-out machine like the old RS. The only weight saving measure is the part-leather part-Alcantara lightweight bucket seats. Oh yes, your dog may be disappointed to find out the rear seats have been discarded to save weight. Obviously, the GT3 is not a car to take your dog outside for a walk. Chassis and Aerodynamics  Now we
go to the technical side. From the specifications you will find the new
GT3 is wider than the old car by 38mm. Compare with the current Carrera
S, it has the same width but ride height is lowered by 20mm. This mean
its handling is inherently more stable than either cars. As before, the
GT3 is built on the Carrera 4 monocoque chassis to take advantage of
its stiffer front end structure and the possibility of fitting a bigger
fuel tank for racing purpose, but it is still rear-drive only. What
made difference is the upgrade from 996 to 997 chassis, which brings 8
percent higher torsional rigidity and 40 percent higher bending
stiffness. To offset the extra reinforcement are aluminum bonnet and
doors (like the new Turbo). Overall, the GT3 weighs only 15 kg more
than the old car, or actually the same as a base Carrera.Aerodynamics is another area of improvement. To compensate the larger frontal area due to the extra width, The engineers at Weissach fine sculpted the double-plane rear spoiler and used smooth underfloor panels to reduce drag. As a result, drag coefficient is reduced from 0.30 to 0.29, which is probably the best figure a sports car can achieve. Interestingly, the GT3 does not seem to be a model of modern aerodynamics, as it does not have any diffusers (the rear engine won’t allow that) thus need to seek help from old-fashion rear spoiler. However, the low drag and the high-speed stability displayed from its driving let us rethink whether rear spoiler is really a thing of the past. GT3 proves that, if properly engineered, rear spoiler could lift the styling as well as aerodynamic efficiency. Take note, Ferrari. Engine and Performance Last year, Carrera S introduced a 3.8-litre version of the boxer engine. Naturally, we expected the new GT3 engine to enlarge to 3.8 litres as well. After all, more capacity and more power is the current trend of engine development. However, the GT3 engine is a development of the 1998 GT1 racer, hence having no relationship at all with the rest of the 911 family. Unlike other 911 engines, it employs very large bore (100mm) and short stroke (76.4mm), versus the Carrera’s 96.0mm x 82.8mm and Carrera S’ 99.0mm x 82.8mm. In addition to lightweight pistons and titanium connecting rods, one can easily see its racing genes. Unfortunately, Porsche stopped developing the racing engine long ago. To increase its capacity beyond 3600cc will require a thorough redesign and substantial investment, which is considered to be too expensive for the low volume GT3. That’s why Porsche decided to retain its capacity and rework the components to find extra efficiency. So what changes did it make? At the intake side, it increased the diameter of throttle butterfly from 76mm to 82mm. It also added a new resonance type variable intake manifold (previously called Varioram) to optimize torque across a wider band. At the exhaust side, it employs larger volume silencers to reduce back pressure. At the valvetrain, it increased the valve lift by 0.4mm and extended the variation range of the Variocam system from 45˚ to 52˚. In the combustion chambers, the compression ratio is lifted from 11.7 to 12.0:1. In the reciprocating parts, the conn-rods are lengthened to reduce thrust angle, hence wasting less energy. The pistons become shorter and lighter. All these put together, the new GT3 engine becomes even more revvy and powerful than ever. It produces 415 horsepower at 7600 rpm, which translate to an astonishing 115 horsepower per litre, even higher than Ferrari F430 (114 hp per litre) !! maximum torque now increases to 299 lbft at 5500 rpm. Max rev is lifted to 8400 rpm, almost like a touring race car. To let you see the progress of the GT3 more easily, I made a comparison table here:
As seen in the table, the new GT3 can top 193mph and accelerate from 0-100mph in only 8.7 seconds. That put it very close to Ferrari F430 (196mph, 8.1sec) and earn it a place in the world’s supercar club. More brilliantly, such performance is achieved by a naturally aspirated engine displacing only 3.6 litres. One word describes this car best: Efficiency. Suspensions and Brakes  Like
other 997s, the new GT3 has added PASM (Porsche Active Suspension
Management) with adaptive dampers. Normal mode and Sport mode allow
different stiffness to suit road or track use. The 19-inch lightweight
wheels are shod with semi-racing Michelin Pilot Sport Cup tires which
can deliver up to 1.4g cornering force ! in case they run out of
traction, the limited slip differential will intervene. If that is
still not enough, the new traction control will ease off engine
power to regain traction. Of course, for a driver’s car like this you
can switch off the TC completely.Like the new 911 Turbo, the GT3 is offered with 350mm diameter ventilated disc brakes with 6-pot front and 4-pot rear calipers. Considering the GT3 is almost 200 kg lighter than the 4-wheel-drive Turbo, its braking performance must be sensational. However, most drivers are likely to pay for the optional 380mm PCCB ceramic brakes, as they are simply fade-free on race tracks. On the Road The GT3’s boxer engine is gem. Initially it feels no different from a regular 911 engine, delivering the same tractable manner and lovely 911-style exhaust note. Prod the throttle and you immediately feel the difference: like a race motor, its rev goes up and down quickly, thanks to the lightweight internals. As rev rise, the turbine-smooth willingness transforms to enthusiastic eagerness – the boxer encourages you to go harder and harder until the 8400rpm limit is exploited. There is no tremendous g-force like a supercharged V8, but the superb willingness and linearity of the GT3 engine delivers even more driving satisfaction to keen drivers.  Achieving
top speed at Autobahn is easy, as the GT3 displays remarkable
aerodynamic stability at high speed. This is a noticeable improvement
from its predecessor. The damping also promotes high-speed stability.
At low speed, the damping at the normal setting of PASM is slightly
more comfortable than the last GT3. That said, on rougher surfaces the
ride quality is barely acceptable. The sport mode is even more crashy,
thus it is better to be left on race tracks.However, the stiff suspension setup results in superb body control and highly precise steering. The handling is close to race car level – sharp and communicative. The grip generated by the Michelin Pilot Sport Cup tires is simply astonishing, so is the tremendous traction coming from the wide rear tires and the 62% weight acted on the rear axle. In the GT3, we don’t talk of understeer or cornering limit, because you need a race track to detect them. Thanks to the superb engine, gearbox, steering and handling, the GT3 is highly addictive to drive. While many supercars deliver higher performance, few could involve its driver as deep as this one. It always tempt its drivers to exploit its deep reserve of rev and grip, and then reward them with precision, communication and speed. Such human-machine interaction has been lost in many modern sports cars. Fortunately, Porsche hasn't forgot that, even though 33 years have gone since the 2.7 RS. |
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| The above report was last updated on 11 May 2006. All Rights Reserved. |
