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2007 GT3 C&D review

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Old 04-07-2006, 02:31 AM
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Thumbs up 2007 GT3 C&D review

http://www.caranddriver.com/shortroa...1-gt3-997.html

You know it’s got a 415-hp race-derived flat-six, rear-wheel drive, and electronic damping, but what’s it like on the road?
BY DAVE VANDERWERP
May 2006


Driver involvement — it’s what distinguishes cars we lust after from cars that merely have impressive performance specifications. It’s what makes a Porsche Boxster so much better to drive than the quicker Corvette convertible. It’s also what gives us job security, since there’s no reliable way — other than getting behind the wheel — to predict if a new model possesses this car/driver relationship.

A high-revving naturally aspirated engine often indicates that a car’s engineers have made driver involvement a priority. Working to keep the engine screaming high in the rpm range — and being drawn into the wailing soundtrack — is almost always more rewarding than standing on the gas of a mega-torque turbo.

This thought kept bouncing around in our heads while wringing out the latest and highest-revving version of the 997 Porsche 911 — the GT3.

2007 Porsche 911 GT3 997 Driving Impressions
Even at idle, you know this is something special. The seats tremble from the high-strung flat-six’s lumpy idle, and a stab at the throttle yields instant response. The GT3 goads you to stand on it, and you submit. As the car screams through first gear (in less time than it takes to read this sentence), it becomes apparent that the GT3’s gearing is noticeably shorter than that of other 911s. Above about 4000 rpm the cabin fills with a robust growl as the exhaust bypass opens up. Initially, you shift by sound at about 6000 rpm, and the engine feels impressive. But then you realize that you’ve got another 2400 rpm to play with, and when you push into the upper reaches of the power band, there’s an awakening at 6000 rpm. The engine absolutely shrieks to the 8400-rpm redline. Anyone listening on the outside is treated to a fantastic race-quality wail. Your neighbors will hate you. Your neighbors’ kids will love you.



On the track, of course, is where the GT3 shines. At first, we thought there was noticeable understeer through some lower-speed sweepers, but it turns out we hadn’t started trusting the massive grip of the rear tires yet. Blasting out of a corner, the GT3 has shocking traction — its 415 hp scorches the ground. If you push too hard, the tires break away predictably, and the GT3 is never scary — no amount of experimentation with jumping off the throttle could get the rear end to come around. All the cars we drove had ceramic brakes, which are absolutely fade free and provide a slop-free feel that other companies should benchmark. The short shifter is a welcome improvement, although engagement is now crisp and effort is higher. On the street, we were almost thinking it was notchy, but those thoughts vanished at the track, where the gearbox works perfectly.

Most of the cars we drove had the carbon-fiber seats, which feel like they’re bolted directly to the floor, placing the driver low in the cockpit. With stiff and aggressive leg and shoulder bolstering, they’re perfect for track work. But they wear quickly on leg and shoulder comfort during any significant street driving, making the U.S.-spec GT3’s grippy sport seats a reasonable choice.

But what’s so impressive about the GT3 is that despite a major increase in ultimate performance, it also works so much better on the street. The active dampers (PASM), while much stiffer than on standard 911s, go a long way to smoothing out imperfect roads. In normal mode, we were pleasantly surprised not to take a beating over some rough roads we encountered. But picking the extra-firm sport mode makes a dramatic difference.

At high speeds, the new variable-ratio steering dials in some sneeze room to get rid of previous darty behavior. And the GT3 kicked its habit of following pavement grooves. But don’t worry; the steering still gives excellent feedback and has an always precise feel.

Okay, so the GT3 isn’t a likely option for a daily commuter, nor is it likely to be someone’s only car. But for pure driving enthusiasts — people that probably think the 911 Turbo is an autobahn cruiser for fat-cat execs — with a six-figure track-toy budget, what a sweet choice.

2007 Porsche 911 GT3 997 Background
The 911 GT3 is the street version of Porsche’s production-based racing cars, the GT3 Cup and RSR. This is the second version of the track-junkies’ 911 that we will get in the U.S. when it goes on sale in August, starting at $106,795. Porsche plans to sell about 800 in the U.S. the first year.


2007 Porsche 911 GT3 997 Engine
This isn’t the same engine as the 3.6-liter in more pedestrian 911s (if you believe such things exist). The GT3 shares its dry-sump engine with Porsche’s production-based racing cars — the GT3 Cup and RSR — and the Turbo. Standard 911s use a two-piece engine block split down the center line of the crankcase. On the GT3 and Turbo, it’s a four-piece unit with crankcase parts cast separately, which are then bolted to the cylinder blocks. This is a stiffer arrangement, which can handle more power, and was originally developed for racing applications.

For the 2007 GT3, Porsche sticks with the same aluminum 3.6-liter flat-six but ups the power by 35 hp to 415 at 7600 rpm, making it the most powerful naturally aspirated 911 ever. That’s also the same output as the last-gen Turbo. And the redline rises by 200 rpm to a stunning 8400, up there with the best, just 100 rpm shy of the Ferrari F430’s redline. But the GT3 makes 115.3 hp per liter — more than the Ferrari and just about anything else. Torque is up 15 pound-feet to 299 at 5500 rpm.

These gains have come largely by lightening rotating components and making the engine breathe better. A new crankshaft design saves 1.3 pounds. Reshaped, forged pistons and 1-mm-smaller (in diameter) piston pins shave an ounce per cylinder. The titanium connecting rods also got thinner. The compression ratio is up to 12.0 from 11.7 in the previous GT3.

In the exhaust, the GT3 has new silencing flaps that, when open (above about 4000 rpm at load), reduce back pressure by eight percent compared with the old GT3. The entire exhaust system has thinner walls than before and weighs almost 20 fewer pounds.

Other updates include a slightly larger throttle body, to better feed the three-stage variable-intake manifold (the 996 GT3 had a two-stage unit), and a wider operating range for the variable intake-valve timing. It can now adjust over 52 degrees, versus 45 degrees previously.

2007 Porsche 911 GT3 997 Transmission
The six-speed manual transmission is largely the same as the previous GT3’s (including steel syncros and an oil cooler), though the second-through-sixth gear ratios have been shortened slightly. Shift throws are 22-percent shorter than those in other 911s. The limited-slip rear axle has a familiar 3.44:1 ratio but is beefed up compared with lesser 911s.

2007 Porsche 911 GT3 997 Chassis
The GT3 is based on the 911 Carrera 4’s mechanicals, but it wears the Carrera 2’s narrow sheetmetal, and instead of all-wheel-drive hardware up front, Porsche mounts a larger, 23.8-gallon fuel tank (a 0.3-gallon increase). The new GT3 benefits from an eight-percent increase in torsional rigidity over the previous car. Bending stiffness is up 40 percent.

For the first time, the GT3 has Porsche’s active shocks — called Porsche Active Suspension Management (PASM) — which have worked wonders on 997 911s and 987 Boxsters to date. PASM offers two choices: a sport setting geared toward track use and a normal mode for the street. The GT3’s suspension is a stiffer version of the strut front and multilink rear arrangement from other 911s. Its anti-roll bars are more substantial as well as adjustable — five-way in front and three-way in back. Both the front and rear suspensions are height adjustable.

No additional weight increase came from the 19-inch (one inch larger) alloy wheels. They’re 8.5 inches wide up front and 12.0 inches wide in back. Wrapped around them are GT3-specific Michelin Pilot Sport Cup tires in the same size as on 4S models — 235/35 front, 305/30 rear. But these tires have precious little tread, so driving in the rain is done at your own risk. And with a tread-wear rating of 80, which is less than half that of a typical high-performance street-car tire, these tires will ensure that they’ll know the sound of your voice at Tire Rack.

Also new to the GT3 is a full-function traction-control system similar to that on the Carrera GT. The system applies individual brakes to keep the rear wheels spinning at the same rate but will cut engine power if both wheels are slipping excessively. There’s a sport button that raises the thresholds slightly (that same button alters the engine mapping for a little more midrange), as well as an off switch that fully disables the system. But the system doesn’t have stability control like other 911s, so driver skill is required.

The 13.8-inch front vented-and-cross-drilled discs (0.8 inch larger than those on the 911 S) are the same size as the previous GT3’s. The rears are also cross-drilled and vented, but they now measure 13.8 inches, up 0.8 inch over the old car. Larger Porsche Ceramic Composite Brakes (PCCB) are optional (15.0 inches front, 13.8 inches rear) and save 44 pounds over the standard steel setup. This is a larger version of PCCB — a size shared with 911 Turbo — but the internal venting design of the discs came from Cup-car development.

Like other 997 911s, the GT3’s steering ratio is variable, which is intended to increase high-speed stability. Thankfully, it remains constant until you really crank the wheel, at which point it speeds up — but this only comes into play in low-speed maneuvers; if you’re cranking the wheel far enough to invoke the faster ratio at high speeds, you have worse problems than the variable steering ratio!


2007 Porsche 911 GT3 997 Exterior
The GT3 is even more extroverted than before and looks outrageous on the road. It sits 1.2 inches lower than a base 911 and has an extremely low front fascia with gaping air intakes that insure proper brake and radiator cooling. There’s also an air outlet in front of the trunklid, which reduces front lift by forcing the air passing the central radiator up and over the car. The telltale bi-level rear wing remains, and the top portion is adjustable. Another striking difference is the center-exit rear exhaust pipes, which mimic the race car’s — a first for the street version.

But looks can be deceiving: Despite all the spoilers and bodywork, Porsche engineers have reduced the GT3’s drag coefficient by 0.01 to 0.29 (same as a 911 S).

Porsche says the GT3 weighs the same as a base rear-drive 911, or 3250 pounds. That’s up about 30 over the last model despite some 44 pounds saved with aluminum doors and trunklid as well as a plastic rear engine cover.

2007 Porsche 911 GT3 997 Interior
The GT3’s interior looks much the same as that of other 997s, which is to say significantly more upscale than before. The GT3 adds an Alcantara-covered steering wheel, shifter, parking-brake lever, and door accents. The gauges have yellow needles and markings (à la Carrera GT) as well as a GT3 logo. Grippy and heavily bolstered Alcantara-lined sport seats are standard. The race-car-like, 23-pound carbon-fiber buckets from the Carrera GT are optional but not in the U.S. And due to the 997’s Porsche Communication Management (PCM) central command screen, there’s no center-console delete option as on previous GT3s. As with all "GT" model 911s, there’s no back seat. Another option U.S. buyers can’t get is the no-cost Clubsport package, which adds a roll cage bolted in the rear, a six-point harness for the driver’s seat, and a fire extinguisher. And of course, there are numerous leather and carbon-fiber trim upgrade options as on any Porsche.

2007 Porsche 911 GT3 997 Performance
Porsche predicts identical 0-to-60-mph times for the new GT3 — we got 4.0 seconds with the old car — but it should shave a couple tenths off the quarter-mile time (think 12 flat), as well as raise top speed 3 mph to 193 (at 8000 rpm in sixth gear).

Skidpad grip should also be higher than the 1.03 g we measured in the last car due to the more-aggressive, softer tires. And we expect that braking from 70 mph should improve 15 or so feet to about 150.

Porsche says that during development the 911 GT3 997 recorded a 7:47 lap around the benchmark Nürburgring Nordschleife circuit. But engineers say the time with the final setup should drop into the 7:42-to-7:45 range. That’s about 10 seconds better than the old car and also a few seconds quicker than the 997 Turbo. We’re sure Porsche would be pleased if the GT3 matches the Corvette Z06’s 7:42 lap time, but it’s still a ways off its big-brother Carrera GT’s 7:32 pace.
Old 04-07-2006, 10:32 PM
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Andy (Portland, OR)
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Alcantara steering wheel?????



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