A Porsche PR representative once told me: "Other companies will put money on the hood of a car near the end of its lifecycle. Porsche chooses to put money under the hood." Putting money "on the hood" basically refers to manufacturers discounting or offering cash back. He's saying Porsche puts more money into the actual car. That's one way to think about the 2015 911 Carrera GTS range.
Strictly speaking, this could be considered little more than a value package, offering all the performance options available on any other Carrera S at a discounted price. Or you could look at it as the distillation of the Carrera S and 4S, giving the enthusiast what he or she wants with a little extra in terms of aesthetics and cachet.
For all GTS models, Porsche starts with the Carrera 4S body. This is the only way those wider rear fenders are going on a rear-drive Carrera. The more aggressive exterior is courtesy of Porsche's Aerokit Cup front bumper, aero side mirrors, blacked-out trim and matte black center-lock 20-inch wheels normally reserved for the GT3 and Turbo S. For those interested in changing wheels at the track, Porsche says the switch to five-lug is a no- cost option.
Speaking of no-cost options, the GTS lettering may also be deleted from the rear and sides, while silver wheels, power folding mirrors and a sport steering wheel are all for free if so desired.
Standard equipment on the GTS that is normally optional on the Carrera S includes the Sport Chrono Package, Sport Exhaust, bi-xenon lights with PDLS (Porsche Dynamic Lighting System) and PASM (Porsche Active Suspension Management). Inside, four-way adjustable sport seats are standard, but can be upgraded to 18-way.
The stock cabin sports a mixture of leather and Alcantara. An additional $4,120 bags the GTS interior package, adding contrast stitching on panels; carbon fiber door, dash and console trim; contrasting tachometer face; embroidered (silver or red stitching) seats and mats.
The 430hp, 3.8L flat-six is the same engine found in the Carrera S models, pumped up with the optional X51 Power Kit. In standard Carrera S trim, the engine produces an already astounding 400 hp. If you think you can easily duplicate that on non-GTS models for less than the $17,800 premium, you are probably mistaken.
The differences start with a two-stage, variable-geometry intake manifold. Porsche uses one butterfly valve in the main plenum chamber and then individual butterflies in each intake runner. When an intake valve is open, the combination of descending piston plus outside ambient pressure forces air into the combustion chamber at high speed. When the valve closes, that charge bounces off the valve face and is reflected back up the intake runner toward the plenum chamber. It will then pressurize the plenum, which in turn sends another pressure wave back down the runner. If that wave reaches the end of the runner just it is re-opening, the charge rushes in with more energy, causing a small supercharging effect. The pressure wave's speed is relatively constant at the speed of sound. Obviously, it's dependent on air pressure, but that's a story for another time.
Since the time between the intake valves opening is dependent on engine speed, or rpm, a fixed-length intake runner can only be optimized for a specific rpm. By deploying flaps in these intake runners and the plenum, Porsche can optimize resonance charging at different engine speeds. With this setup, it is possible to see volumetric efficiencies of greater than 100 percent, meaning a cylinder with a volume of 633 cubic centimeters might be able to pull in 650 cc or more, allowing it to perform like a larger engine.
Much like the intake plenum, camshafts are usually optimized for one particular engine speed. Here, Porsche uses two different cam profiles to change lift at different rpm as well as variable cam timing to select when valves open in relation to piston position. The GTS and X51-equipped cars both use a more aggressive cam profile for higher revs, allowing the engine to breathe deeper for more power.
On the other side of the boom, Porsche's sport exhaust allows for lower back pressure, adding to performance as well as producing a great noise. The system is variable, with valves that not only maximize flow rates, but also allow for more or less sound, depending on preference.
Lastly, the included Sport Chrono package brings active engine mounts, which soften at low-torque operation to reduce vibration and noise, and stiffen up during higher-torque operation and during greater g-loads to stop powertrain movement.
With that brief science lesson out of the way, let's drive. Any GTS is, in a word, sublime. As stated earlier, it really isn't that much different from a Carrera S with a careful selection of driver-focused options. In the end, however, it gels into a wonderfully cohesive package.
To see what these models are like in the real world, we hit the Angeles Forest Mountains outside of Los Angeles in a rear-wheel-drive, PDK coupe (Guards Red, if you're wondering). The car is immediately familiar to 911 drivers. The seating position is as good as it gets, with plenty of headroom and a steering wheel that tilts and telescopes enough to accommodate just about any human body type out there. The sport seats are supportive and the ergonomics are near-perfect.
The sport exhaust adds rumbles and grumbles that fit the car's character perfectly and give that crackly bark during overrun and shifts. In some older versions, Sport mode was almost too aggressive for the street, with throttle tip-in making the car feel jumpy. And it would hold gears for too long. Comfort Mode, however, was too relaxed and focused on fuel economy. Sport now feels more adaptable and the car seems smart enough to figure out the driver's intentions pretty quickly.
The GTS is most at home on the main roads going up into the mountains. It excels through big sweepers and over fast switchbacks. It soaks up bumps and covers ground as fast as anything out there. Mid-range torque is addictive and the performance envelope hovers above legal limits by a decent margin.
On roads like these, power output is perfectly matched to the chassis and you hardly ever find your foot all the way to the floor or even zinging to redline. The twisty-ness of the tarmac won't allow it.
Switching over to lesser-traveled canyons is a reminder of how much the 911 has grown over the years. On roads that at one time would have been the natural habitat of an air-cooled 911, the 991's width is immediately obvious and even slightly unwelcome in some instances.
The car wraps itself around you and you know where every corner is. But sometimes the passenger-side fender is either uncomfortably close to a cliff wall or a 100-foot drop. Suddenly, driving fast is more about lane management than hitting the best cornering lines.
For someone who runs a lot of small canyons, I might suggest a base 911 (or dare I say?) even a Cayman. Luckily, the body control and sharp steering remove some of the guesswork from the situation.
Canyon driving gave way to track driving at Willow Springs Raceway, with every model of the GTS ready to roll: rear-drive and all-wheel drive, coupe and cabriolet, manual and PDK.
First, let's address transmissions. Porsche has, in its own words, retuned the seven-speed manual for the GTS. It may be the best in the business. Shifts are precise and smooth, with a mechanical feel few others can match. The clutch has the perfect resistance and bite point. This is a last Hail Mary for the manual and Porsche could not have made it any better. If I were looking at a convertible, or maybe even a coupe with no intention of ever going to the track, I would buy it without hesitation. I would never regret it while sitting in traffic; I wouldn't regret it driving in canyons. The rev-matching in Sport Plus mode is better than I can do, and an occasional clutch drop 0is good for the soul. No remorse-until, that is, I drove it back to back on a racetrack with the PDK.
Even in full automatic mode, the PDK is superior on the track. Shifts are blindingly fast and slick, and the car follows orders through the shift paddles with Doberman-like obedience. Clutch pedal fans, I'm sorry, but I'm officially won over.
Driving rear- and all-wheel drive GTS versions one after the other is enlightening. If you believe powering the front wheels spoils right-foot driving or contaminates steering feel, you're dead wrong. Both cars will swing around with a big punch of the throttle. The difference is that when you creep up to a Carrera 2's limits, a little more throttle rotates the car. That's fine, but more push just produces more rotation and you scrub speed.
In the Carrera 4, when the limit comes up and you apply more throttle, the car pushes the power around and figures out which end can best utilize it. It keeps accelerating while the rear-driver is putting on a drift show. You can get the C4 into a four-wheel drift by adding throttle gently. This will cause involuntary yodeling and rally-induced smiling that will last for days.
In the past, Big Willow probably wouldn't have been the best choice to show off a 911. There are two spots in particular that, in earlier generations, are typically hair-raising. One is the transition between turns four and five. To be fast, the downhill section requires a movement from throttle to brakes while applying steering input. Anyone familiar with 911s knows this would have been a recipe for disaster. The GTS with PASM comes to the rescue. Gone are the big-attitude changes associated with lifting out of the throttle. The rear end stays dutifully in line and allows the whole section to be conquered in big sweeping arcs, rather than cutting it up into sharp turn, straight, followed by another sharp turn.
The second troublesome area is between turns eight and nine. The GTS is doing in the neighborhood 120 mph here and, again, it requires simultaneous turning, lifting and braking. Not only is PASM a lifesaver, but I have a feeling the active engine mounts aren't hurting either. Cars normally have an initial weight transfer and then a secondary one when anything on flexible mounts "catches up." With active mounts, this is no longer an issue.
I'm not a convertible guy; I would probably never buy one. That said, I have to admit that driving one right after a coupe is probably the only time you can find a downside to the open-top version. It feels slightly heavier and ever so slightly less responsive. Going from a C2 tin-top to a C4 cab, the weight difference is eye-opening. The change in weight isn't nearly so dramatic when driving a C4 coupe immediately afterward.
If it were my money, I'd order a white Carrera 4 GTS coupe with the interior package, Bose audio, Park Assist with camera, European delivery, PDK, PASM sport (which lowers the car an additional 10mm) and painted key (it's a special car, why not?). All this would set me back $139,725 with delivery. You might say: "Hey, the GT3 bases at only $131, 395. Why not just get that?" Well, if it was just a track or weekend car, that would no doubt be my choice. If, however, I wanted to drive this car daily, I would go GTS. A comparable C4S would cost around $147,695, by my calculation. Once GTS models start hitting dealerships, I have a hard time imagining someone walking in and not buying one over the standard S. It could happen, though; maybe some customers will talk dealers into putting money on the hood.