Porsche have long-proven the status of their GT cars by setting some of the fastest lap times. But Mercedes have emerged from the shadows to challenge the status quo
Ever since the first Porsche 911 GT3 RS was launched in 2003, it has captured the imagination of car fanatics. Back then, the 996 iteration was initially produced as a homologation special, Porsche never had any intention of adding it permanently to the model range. But this harder and faster variant became the catalyst for the inclusion of the track orientated 911. This intoxicating concept now spans seven generations, and it has reached something of a crescendo with the newest example. It’s probably the most hardcore and extreme 911 ever made, for now at least.
You know the score with the GT3 RS. If we take the theory of evolution that defines the approach Porsche has towards the 911, then the latest 992 version of the GT3 RS is second only to the bonkers GT2 RS as the ultimate Porsche GT car in the pecking order. The most significant change though that separates the 992 GT3 RS from previous generation GT cars is the considerable incorporation of aerodynamics into the design and development process. Just from looking at it there can be no equivocation, it has all the hallmarks of what you would expect to see on a racing car, except it can be driven on the road.
Andreas Preuninger is the Director of the GT Product Line. Him and his GT Division team had the challenge of raising the bar for the 992 GT3 RS. To achieve this, it has required them reaching for more advanced and sophisticated motorsport technologies to improve performance. The components that have been utilised are closely linked with the 911 GT3 R customer race car, and these have elevated the 992 GT3 RS to another level. In pursuit of the fastest lap times possible, Porsche haven’t made compromises with the 992 GT3 RS, it’s effectively been sculpted by airflow.
To extract the maximum amount of performance, it’s a necessity. Form must follow function; everything must have a purpose. At the front is a large and angled central radiator, an innovation first adopted on the 911 RSR and 911 GT3 R racing cars. This unit is situated where the front storage compartment was and has enabled active aerodynamic elements to be integrated into that vacant space. All the air sucked into the front radiator flows out of two nostrils in the bonnet and is channelled down the side of the car.
"Porsche understands what it signifies. In setting rapid lap times, they are throwing down the gauntlet to rivals"
The front spoiler has been replaced by a front splitter diverting airflow over and under. There’s sideblades deflecting airflow outwards, whilst there’s ventilation louvres in the front wings allowing trapped air to escape the wheel wells. To further reduce that pressure, inlets behind the front wheels dispel airflow down the side of the car. Then there’s the two-part rear wing, which has a drag reduction system (DRS) like what you find on Formula One cars. It's absolutely insane to see something so humungous fixed to a road-legal car, but it’s functional.
These aerodynamic changes make for some incredible downforce figures. The 992 GT3 RS produces 409kg at 125mph, and 860kg at 178mph, which is twice as much as the previous 991.2 generation GT3 RS and three times as much as the current 992 GT3. That's mindboggling to contemplate. You get the distinct impression that Porsche has left no stone unturned, and that notion is reinforced by the fine tuning which can now be done. How the 992 GT3 RS can be setup is dependent on the driving mode. There's three to select from: Normal, Sport and Track.
It practically makes for a professional racing car, it’s a seriously equipped track tool. In Track mode, you can adjust settings individually to your preference. The rebound and compression damping on the front and rear axles can be changed separately, as well as the rear differential. This is done via an operating and display system akin to one used in motorsports. In terms of outright velocity, the 992 GT3 RS has the symphonic 4.0-litre naturally aspirated flat-six engine, which has been tweaked to produce 518bhp. Despite having a dry weight of 1450kg, it could do with some more.
Nevertheless, 0-62mph takes 3.2 seconds, but a price has been paid in top speed. The zero compromises approach has come at a cost. All the aerodynamic components create considerable drag, meaning the 992 GT3 RS is pegged back at 184mph, which is 13mph slower than the regular 992 GT3. The conclusion from the GT Division must been that it was worth it, yet I can't help but think that a reduced top speed inhibits the Porsche on straight sections of race tracks.
The Nürburgring is regarded as the ultimate proving ground for performance cars. For Porsche, it’s been something of a stomping ground for their GT cars, as they have consistently set blisteringly quick lap times around the circuit. For Porsche, this is about much more than showcasing what their GT products are capable of, it’s about establishing their status and asserting their authority as the best high-performance carmaker on the planet. The stopwatch never lies, and Porsche understands what it signifies. In setting rapid lap times, they are throwing down the gauntlet to rivals.
You would think that Porsche have done the same with the 992 GT3 RS. And they have, although not quite in the emphatic manner that they have become accustomed too for reasons I shall elaborate on later. In completing the 20.8km distance in 6:49.328 minutes, Porsche continues to push the boundaries – it’s twelve seconds faster than the previous 991.2 GT3 RS. This obsession with the Nürburgring has become synonymous with the Porsche 911 as the benchmark supercar, to the point where other car companies probably view that dynasty with some degree of envy.
It's hard not to respect the Porsche 911, there’s something almost mythical about its existence. Since its inception in 1963, it has bucked the trend and defied the odds. The concept makes it unique in the supercar landscape, and the progressive philosophy keeps it relevant and moving forwards. It doesn’t feel out of place or out of sync, it’s just a timeless reminder that nothing stands still, change is constant, and improvement is incremental. No other carmaker has ever really produced a credible alternative to compete with the Porsche 911 at its own game on its own turf.
In many ways the Porsche 911 is one of a kind. Emulating that phenomenon and competing with it comes with risks, but also rewards. Mercedes are the challengers that have emerged from the shadows, and they have done so with intent. The equivalent model that was launched as the direct rival to the 911 was the AMG GT back in 2014. In isolation, it was a good car, but when compared with the 911 Carrera, the contrast was stark. It lacked the dynamism, finesse and poise of the Porsche, and there was a sense that it wasn’t as complete either.
"What’s noticeably apparent between these two cars is that they have similarities and differences in equal measure"
The AMG GT has now reached the end of its current model cycle, with the second generation set to drop in the near future. But Mercedes has left the track version of the first-generation AMG GT to last. Eight years of design and development has culminated in the AMG GT Black Series. Revealed back in 2020, it’s the hardest and fastest variant, a track weapon that takes no prisoners. What’s noticeably apparent between these two cars is that they have similarities and differences in equal measure, which makes the rivalry all the more intriguing.
What the 992 GT3 RS and AMG GT Black Series have in common is the approach that Porsche and Mercedes have taken towards aerodynamics. The adoption of motorsport technology from their track car equivalents is evident, and those close links have extracted even more performance potential. For the AMG GT Black Series, like the 992 GT3 RS, elements from the AMG GT3 and AMG GT4 racing cars have been integrated into the design. An aspect that bares a striking resemblance is the two openings in the bonnet to improve aero-performance.
These two exhaust outlets direct warm air out of the engine bay. This increases downforce, reduces air resistance and optimises engine cooling. The airflow is guided around the side windows and towards the back of the car to increase the efficiency of the two-stage rear wing, which looks completely crazy. It’s just as ginormous as the one on the Porsche, although the concept is different on the Mercedes. There are two aerofoil wings that can be adjusted for different track requirements. On the upper blade is an active flap that moves between flat and inclined positions to optimise performance.
This slight differentiation in rear wing innovations highlights a similar train of thought that Porsche and Mercedes had to maximise lap times. Increasing downforce across the front axle are five louvres positioned in the front wing that ventilate air from the wheel arches. The underbody is shaped by aerodynamics and the need to dissipate heat, which is done via longitudinal fins that channel airflow towards the rear diffuser. This is an overview of the development that has been undertaken, but Mercedes says all the measures mean there’s over 400kg of downforce at 155mph.
The most notable contradistinction between the 992 GT3 RS and AMG GT Black Series is the powertrain, which illustrates the opposing philosophies with each car. The 4.0-litre V8 biturbo engine is mounted in the middle and has been modified with a flat crankshaft to produce more power, better throttle response and optimum torque. Along with other changes, it now has 730bhp, which is a significant amount more than what the Porsche does. But while 0-62mph takes an identical 3.2 seconds, the top speed is considerably higher at 202mph.
It's something that plays into the hands of the Mercedes, as the Nürburgring lap time testifies. The AMG GT Black Series completed the 20.8km distance in 6.48.047 minutes, just 1.3 seconds faster than the 992 GT3 RS. It’s quite astonishing just how evenly matched both these cars are. Considering the differences in approach Porsche and Mercedes have taken, and yet the outcome in terms of lap time on the track is that close, which is extraordinary. But the remarkable revelation is that the AMG GT Black Series is quicker than the 992 GT3 RS, something few would have expected.
Mercedes have beaten Porsche, which is quite an accolade when you think about it. On the other hand, the 992 GT3 RS demonstrates that fast lap times don’t just come from power output from the engine. Even so, there’s the lingering notion that it does need more power to fulfil its ultimate potential – 20bhp more would be sufficient. For this reason, I think the Porsche is the better engineered car. Mercedes are testing the reputation of Porsche GT cars at the Nürburgring, and it only makes me wonder just what the upcoming 992 GT2 RS will be like when it breaks cover.
Photos: Porsche & Mercedes
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