Follow-Up Test: 2007 Porsche 911 GT3 RS

This is it. The 2007 911 GT3 RS is the reason that Porsche builds the Cayenne. The substantial cash injection provided by the Cayenne's popularity allows the small automaker from Stuttgart to produce low-volume specialty cars like this one, proof that there's at least one sport-utility vehicle that a sports car guy can learn to appreciate.

But what exactly is it? With all its wings and slots and bodacious graphics, the RS looks like a refugee from the starting grid at the Sebring 12 Hours. It sounds like one, too.

Race-Bred
This impression isn't too far off the mark, because Porsche builds the 911 GT3 RS (Rennsport, for "race sport") as a model to homologate the 911 GT3 RSR racing car for competition events like Sebring and the 24 Hours of Le Mans.

The RS is similar in specification to the 911 GT3, but it is built with the body shell of the 911 Carrera 4, as the latter car's 1.7-inch-wider rear bodywork allows the widest possible racing rubber within the fenders. In addition, split rear control arms permit more camber adjustment, another measure for racing applications. And finally, the RS features wheels with less offset than those of the base-model GT3, and they increase the rear track by 1.3 inches.

In another nod to homologation, the RS's plastic rear deck lid is topped by a wide carbon-fiber rear wing, while the deep front airdam has a small aero splitter to improve front downforce and shovel even more cooling air through the radiator.

Too Close To Call
Porsche says the RS is 44 pounds lighter than the GT3, but we've measured the RS at 3,209 pounds, just 29 pounds lighter than the last GT3 we tested.

In fact, the RS is really not so different from a standard-issue GT3. This is largely because the U.S.-bound RS model must do without the European model's bolt-in roll cage, plastic rear window, single-piece carbon-fiber seats and five-point seatbelt harness.

At least we get the RS-specific paint job. Our test car looks positively menacing in its green-and-black color scheme, a $3,070 option. It recalls the original 1972 Carrera RS 2.7, another homologation special (just 1,525 were built) with which the GT3 RS shares its racy nature.

Forget Aesthetics; Let's Drive
We can attest to the effectiveness of the RS's aero elements. Competition drivers from the Porsche Cup recently treated us to hot laps of the La Ceram proving ground in France with the GT3, RS and RSR during a presentation of the new 911 Targa 4. At speeds approaching 190 mph on the banked oval, the RS remained rock-steady on the lumpy pavement, while the GT3's rear end felt ever so slightly less buttoned down.

At less insane speeds, the RS drives much like a GT3. The steering remains a delight, sending clear messages about the texture of the road and delicately changing in effort as the front tires alternately find and relinquish grip.

There's no kickback through the steering wheel, and the amount of steering effort is reassuringly constant, as the variable-ratio hydraulic assist isn't a speed-dependent affair like BMW's active steering. Instead, Porsche's rack-and-pinion quickens its ratio as the steering wheel is turned farther from center, requiring fewer turns of the steering wheel from lock to lock. The result is steering that feels completely natural in parking lot maneuvers all the way up to, umm, faster speeds.

More Than Just the Tires
The RS wears serious 19-inch Michelin Pilot Sport Cup tires, a street-legal yet competition-oriented choice that requires some heat before the full degree of stickiness is deployed. Once warm, there's heroic grip on tap.

A soft rubber compound and shallow tread depth result in limited tire life, however. Replacing them won't be cheap, either.

As magically grippy as these tires are, you can't just slap them on any other car and expect to duplicate the 1.01g death grip the RS has on the skid pad, its slalom blast of 75.3 mph or its predictable demeanor. Just like a racing car, the GT3's suspension has been specifically tailored to this tire, from spring rates to suspension bushings.

Damping Makes the Difference
In true race-prepared fashion, the RS's suspension not only includes adjustable antiroll bars but also dampers with threaded spring collars to expedite adjustments to ride height and corner weights.

Of note is the Porsche Active Suspension Management (PASM), also found in the GT3, although the two-mode dampers have been revalved for the RS. Both the Normal and Sport PASM modes are about a half step more aggressive than those in the GT3, and Normal mode is as firm as you'll find acceptable on the street.

Paradoxically, the RS manages to incorporate enough suspension compliance to help it arc predictably through the corners, even across bumps that would send lesser performance cars skittering into the weeds.

Same Power, Quicker Response
The RS houses the very same 415-horsepower 3.6-liter flat-6 and six-speed manual gearbox found in the GT3. But don't be disappointed, because this is one of the great engines. It's tractable and uncannily smooth, and when provoked it tears to its 8,400-rpm redline with a strident ripsaw cry. Pressing the Sport button opens up the exhaust, freeing up some 11 pound-feet of torque and 14 hp in the midrange, as well as laying down a bass line to the exhaust note.

The RS's lightweight single-mass flywheel transmits more drivetrain grumble into the cabin than the GT3's heavier dual-mass piece, and the idle is somewhat lumpy. Compared to the regular 911, the shift action and clutch effort are heavier, requiring a more deliberate shove.

Clutch take-up is immediate, and the near absence of drivetrain inertia means you have to take some care to launch the RS smoothly from a standstill.

Equal Measures of Power and Traction
The RS has enormous reserves of traction, and its ability to put power to the pavement results in efficient standing-start acceleration. We measured the 0-60-mph sprint in a scant 4.0 seconds and the quarter-mile in 12.2 seconds at 115.6 mph. Quick as it is, the RS feels like it could easily handle another 50 horsepower. (Cue the upcoming 911 GT2, which channels 530 turbocharged horses through the rear wheels.)

Our RS test car feels capable of slowing the earth's rotation, stopping from 60 mph in a jowl-stretching 101 feet. This is the shortest-stopping car we've ever tested, edging the 2nd-place GT3 by just 1 foot.

What's more, the initial bite of the brakes and the ensuing pedal modulation are spot-on in nearly every circumstance, though the optional carbon-ceramic PCCB brakes need a bit of heat to work their best.

Forget the Numbers
The RS gives you an authoritative, unflinching experience as it goes down the road at speed. As cornering loads build, the RS's responses remain remarkably linear, and this progressive feedback paired with the nuanced steering instills confidence that the chassis is always with you. The GT3 RS feels at once coiled to strike and yet calmly poised.

When you drive into a fast corner with neutral throttle, the RS will understeer benignly. The 19-inch Michelins break away gradually at the limit, and there's so much control feel streaming in that you feel completely at ease while adjusting the car's cornering attitude with the throttle or even by trail-braking.

At this point, you had better be on a track, as the velocity has escalated from "ludicrous speed" to "we've gone to plaid." Press on even harder and lift-throttle oversteer can be provoked.

The accomplishment of the RS is not its astonishing performance numbers, but rather its ability to combine the disparate elements of the driving experience into one magnificently cohesive whole, while still allowing the driver to be an integral part of it.

Simply put, words fail us.

The Morning After
The 2007 Porsche 911 GT3 RS is a terrific piece. Trouble is, the regular 2007 Porsche 911 GT3 offers damn near the same driving experience and performance plus a more street-friendly ride, and does it for $17,200 less.

The 911 GT3 RS is a pure Porsche experience. But aside from turning heads, the RS's wider rear end and aerodynamic accoutrements matter only to those who really spend lots of time at the track, where the additional stability makes a difference.

If you're smart, you'll buy a Porsche 911 GT3 and spend the money you save on 10 sets of tires.

The manufacturer provided Edmunds this vehicle for the purposes of evaluation.