Porsche’s second-generation 911 GT3 feels like it has taken a seismic leap rather than an evolutionary step over its already brilliant predecessor.

Two hundred cubic centimetres here, a few hundred rpm there, a rear wing placed mere millimetres higher for more downforce yet no increase in drag, power up 25bhp: the 911 GT3 is the absolute definition of Porsche’s evolutionary approach to its cars’ development. Only, this is a GT department Porsche, and those usual, expected incremental changes add up significantly, so much so that the new GT3 feels radically different to its predecessor, despite what, on paper, look like small improvements.

“It is all about finding efficiencies,” says GT department head Andreas Preuninger. He’s not talking fuel consumption and emissions, of course, but the pursuit of performance. The engine, now up to the same 4.0-litre capacity of the 911 GT3 RS and 911 R before it, isn’t, as you might expect, merely lifted from them; no, it’s actually from the 911 Carrera Cup racers, so this is a homologation engine in the truest sense of the word.

Reading the specification that’s clear, as Preuninger’s engineers have removed the hydraulic valvetrain and replaced it with a rigidly mounted system. That’s pure motorsport in its specification, its adjustment set at the factory, meaning as much as 9bhp over the previous system, and Preuninger says that it’s been tested to the life of the engine.

There’s a new crankshaft, too, which is hollow, yet stiffer, oil feeding the bearings down its core, which alone allows for the loss of over 12 spray nozzles internally, reducing the pumping and splashing losses in the engine and significantly reducing the amount of oil circulating. Lower friction surfaces on the bores, lighter internals, dual intake flaps for improved low-rev response, ram-air scoops on the engine cover and more all add up to a faster reacting and more powerful engine. The result of all of that is 500bhp at 8,250rpm, 460Nm of torque at 6,000rpm and a redline at a stratospheric 9,000rpm.

The PDK seven-speed twin-clutch transmission has been finessed for quicker shifts, too, though the GT3 is now also offered with a development of the six-speed manual gearbox developed for the 911 R — a popular choice among Porsche’s more hardcore, purist audience.

Visually, the new 911 GT3 is very close to its predecessor, though the rear wing now sits higher and a little bit further back, which, in conjunction with significant underbody aero changes sees a 20 per cent increase in downforce — up to 155kg at top speed — without any corresponding increase in drag. Helping at top speed is an additional 20bhp or so from the ram air effect into the engine, which was previously something of an RS feature.

Other efficiencies include revisions to the spring and damper rates, while the rear gets ‘helper springs’ for improved control. The steering has been finessed on both axles, the GT department’s engineers revising the set-up of the rear-wheel steering system to improve both stability and control.

PDK-equipped cars come with Porsche Torque Vectoring Plus and an electronically controlled differential, while the manual car makes do with just Porsche Torque Vectoring and a simpler mechanical locking differential, though the manual car is 17kg lighter, with a kerb weight of 1,413kg compared to the 1,430kg of the paddle-shifted vehicle. There’s little in it regarding performance; the statisticians among you will note the PDK’s greater ferocity during initial acceleration, with a 0-100kph time of 3.4 seconds, in comparison to the manual’s 3.9-second result, but the gap drops to 0.4 seconds by 200kph (11.0 seconds in PDK, 11.4 seconds manual), while the six-speed three-pedal car gets bragging rights to v-max with its 320kph top speed over the PDK’s 318kph.

No matter which you choose, they’re both ferociously quick, a sensation that’s highlighted by the engine’s incredible response. If you need a reminder that, for immediacy, natural aspiration is the best route, then you need to drive the GT3. The way the engine responds to your inputs is incredible, the merest touch of the accelerator revving the engine with an enthusiasm that has to be experienced to be believed. There’s low rev response too, though; the engine might be a racer at heart, but that’s not to the detriment of its driveability, so it can be driven in higher gears at all times if needs be, though doing so is to deny yourself one of the most intoxicating, visceral connections between man and machine currently available.

Doing so is to deny yourself one of the most intoxicating, visceral connections between man and machine...

That low rev potency is aided by the dual intake flaps, so torque arrives earlier and fatter than in the old 3.8-litre GT3 engine. It’s more linear in its response as a result, feeling keener to rev than even its RS relation, even if the trade-off for that flexibility is a slightly lacklustre engine note below around 4,000rpm. Hang on though, as get the needle above that and the sound it makes is a mechanical symphony that’ll have every nerve jangling, and the tuneful mechanical sound it delivers from 4,000rpm hardens above 6,000rpm to a sort of maniacal shriek as it wrings out the last few revs before the red paint at 9,000rpm.

Do that once and you’ll be utterly addicted, dropping ratios at any chance to hear the flat-six’s note — doing so is eased by the ridiculous speed on offer from the PDK transmission. Just think your gear change and it’s as if the transmission knows, as the time between tugging the right paddle for an upshift to it happening is so quick it’s seemingly immeasurable; downshifts too are undertaken with the same incredible speed, announced by a rev-matching blip on the throttle. There’s no slack in the system, even with the manual, which you might think would be overwhelmed by the speed of the engine’s response. It isn’t; the six-speeder’s shift is so well judged that it’s  more than up to the job of controlling the 4.0-litre unit’s outrageous output and immediacy, though it does demand a little bit more from you over the PDK.

Both are immersive driving experiences, neither being ‘better’ than the other, instead best described as different — the GT3 is a car that’s rewarding, engaging and utterly beguiling, regardless of which transmission you choose. That it’s able to offer racecar synapses combined with genuine road car civility is little short of extraordinary, Porsche’s most focused car demonstrating impeccably the breadth of ability of the 911. Being singular in its focus, ie the pursuit of speed, hasn’t in any way detracted from its usefulness, if, of course, you ignore the lack of availability of rear seats — the GT3 is, as ever, a 911 for you and one other, the rear compartment more often than not filled with the free Clubsport option that adds a half cage, six-point race harnesses, a fire extinguisher and preparation for ignition cut off. Racer stuff, in a road car, without much compromise.

The front axle delivers unerring immediacy, helped by the rear-wheel steering, while the powertrain’s response is perfectly matched...

If the engine and transmission represent the very finest symbiosis of pistons and gears, they find the perfect home in the GT3’s chassis, which plays more than merely a supporting role. The chassis’ purity of response and sensations it delivers are every bit as addictive as the engine’s ferocity. Like every part of that engine and transmission, the GT department has gone though the entire dynamic package in the pursuit of efficiencies, with that goal of improved response, speed and control.

The cumulative effect is notable on road and track, the GT3 feeling like it has leaped a generation evolutionarily over its predecessor, already a car that was rich in detail and immediate in its response.
It’s impossible to pinpoint a particular area where it’s different, but the steering’s immediacy, weighting and greater feel warrant a mention, and turn-in is almost RS sharp in its alacrity. Meanwhile, the rear feels more stable, so the chassis works convincingly as a whole. The steering wheel delivers rich sensations without being busy, it filtering out unnecessary chatter without robbing it of any of its detail. The suspension delivers such fine control it’s perfectly suited to dealing with the GT3’s sensational performance. The way it can carry its speed, even on rougher surfaces, without requiring you to back off, is mesmerising, though should you need them, the brakes are unerring in their stopping power and the pedal weighting excellent. The ride is necessarily taut, but compliant too, the suppleness it offers at odds with the control it delivers, which must be down to those efficiencies the GT department chased, as the dampers feature less internal friction for even greater response, while those helper springs on the rear axle aid precision and control, too.

At, up to and beyond the GT3’s limits it’s so communicative, so rewarding and informative it’s a car you really can enjoy to its maximum. The front axle delivers unerring immediacy, helped by the rear-wheel steering, while the powertrain’s response is perfectly matched, making for a car that’s got exploitable performance. You don’t need to be driving it fast for it to engage, either, as the GT3 is as interesting at lower speeds as it is intoxicating at higher ones, thanks to the fine feedback on offer.

It’ll move around underneath you if you’ve space on a circuit, that transition of the tyre’s grip to slip easily read, making the GT3 a friendlier car at its limits than the GT3 RS. Easier, then, but no less demanding at the same time, a car that gives on so many levels, and about as exciting as a road car can get. That it’s quicker is no surprise; what might be, is just how much quicker it is, Porsche’s own Nürburgring lap time underlining that: the new 911 GT3 shaves 12.3 seconds off the old car’s time for a 7 minute 12.7 second lap. That it’s faster than the RS is significant, too; efficiency has never been as fast and evolution continues to improve the breed. And some.