Manthey Racing Porsche 911 GT3 RS 2025 review – the ultimate Nürburgring toy

It seems absurd, doesn’t it? How could anyone possibly make the 992 GT3 RS more track-capable or endow it with a meaningful increase in downforce? Moreover, who would be crazy enough to attempt it? The answer to both those questions lies in understanding this car’s creator, Manthey Racing.

Something of a cult amongst fans of hardcore Porsches, Manthey is based in Meuspath, just a stone’s throw from the Nordschleife’s Döttinger Höhe straight. The team’s record in the N24 is the stuff of legend, its seven victories (all achieved with Porsche 911s) matched only by its arch rival, Audi-supported Phoenix Racing, who scored a seventh victory for the R8 LMS last year.

Established in 1996 by successful Carrera Cup, DTM and VLN racer Olaf Manthey, the team rapidly forged a formidable reputation for winning races and making Porsche’s most focused street cars that bit fiercer. Proudly independent for the best part of two decades, Manthey merged with Raeder Motorsport in 2013, with Porsche subsequently acquiring a 51 per cent stake later that same year.

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This began a new era in which the factory would entrust Manthey with its GT race programme, including the World Endurance Championship. Being part of Porsche also changed the way Manthey could work on Porsche’s latest models. Gone were the wild, big-bore engines with capacities from 3.9 to 4.4 litres and power outputs that exceeded 500bhp long before the factory cars managed it. In their place came upgrades for Cayman and 911 GT models that left the powertrain untouched and – crucially – preserved the standard model’s homologation and factory warranty status.

These Manthey ‘Kits’ have been available through Porsche’s Tequipment option catalogue since May 2021. We sampled a 992 GT3 fitted with a full Manthey package last year, when it starred in our 2024 Track Car of the Year test (evo 322). Surprisingly different from the stock GT3 in character and capability, this hardcore take on a familiar Flacht favourite whetted our appetite for what was then Manthey’s very much in-development GT3 RS prototype – a YouTube sensation after a heavily camouflaged and outrageously bewinged car was spotted undergoing testing on the Nürburgring Nordschleife.

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Frustratingly, despite a number of attempts to set a definitive lap time in the finished article, Manthey have been thwarted by sub-optimal weather conditions during the official Nürburgring test sessions. More attempts are scheduled in the first half of this year, but until that all-important lap is nailed, we can only speculate as to what the modded RS will achieve. For context, the Manthey-Kitted 992 GT3 is a shade over 4 seconds faster than the standard model, so the equivalent 992 RS will comfortably eclipse the stock model’s 6:49.328 (or 6:44.848 when adjusted to be consistent with the old, slightly shorter lap variant). 

If looks count for anything, the Manthey RS already has a record in the bag. It is absolutely outrageous from every single angle, and far more extreme in the metal and carbon than Manthey’s own studio images suggest. This much is clear when we collect the first car converted in the UK from Joe Macari Sports Cars in south-west London. We head north towards evo’s home turf, which means a nerve-jangling drive amongst swarms of Deliveroo scooters, swerving Ubers and bullying buses before reaching the relative sanctuary of the motorway.

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The general cockpit vibe is little changed from the regular car. Unsurprising given that it remains stock apart from Manthey kickplates on the sills. The biggest change comes from the replacement of the rear screen glass with a 25 per cent lighter carbon panel that serves as the support for the dramatic shark fin. Rearward vision was never great in an RS thanks to the wing, but only having the door mirrors to see behind you does feel more restricted. This car’s owner intends to install a rear-facing camera, which would be a neat solution.

The effect the Manthey RS has on others is not to be underestimated. Slack-jawed gawps are par for the course. Pedestrians rotate their heads like owls. Other drivers seem slightly bemused, as though a racing car has just joined them on their commute. Phone cameras track your every move. If you like making discreet progress, this car is not for you. But then, to be fair, neither was the standard 992 RS. 

The aero package is as extensive as it is wild. From the deeper front splitter (which now requires additional support from a pair of spindly carbonfibre rods) to the double-element rear wing and huge end-plates, the pursuit of downforce has led to extreme solutions and created a monster.

Downforce-wise, the 911’s limiting factor has traditionally always been the front end. It’s a problem common to all street cars, but prior to the 992 RS it was especially tricky for the rear-engined 911. When the decision was made to sacrifice front luggage space and instead use that area to package a new cooling system and direct airflow in the most efficient way, it unlocked an abundance of downforce at the front, which could then be balanced by fitting a much larger wing at the rear.

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Form following function is an overused term in the automotive world, but rarely is it more appropriate than when describing this car. Dive-planes on the nose feed air onto redesigned Gurney flaps on the front wheelarches. Six additional roof strakes do an even better job of directing hot air away from the engine intakes, while the shark fin, derived from the 963 Le Mans racer’s, provides greater stability through high-speed corners. 

That colossal rear wing still functions via the same DRS system and control software to avoid lengthy and costly development, testing and rehomologation of a new system. Underneath you’ll find a new, wider diffuser featuring deeper fins that run for longer to generate more downforce without added resistance. A finishing touch – and Manthey signature – are the aero discs fitted to the rear wheels.

The result is more than 1000kg of downforce (up from 860kg) at 285kph (177mph). That’s an increase of some 20 per cent with no drag penalty; vital to retain the standard car’s homologation, but also crucial in wringing more pace from an unchanged mechanical package. The aero balance has shifted slightly forwards, by ‘around two per cent’ according to Manthey, which instils greater confidence in less-than-expert hands.

Until now, Manthey’s upgrade kits have replaced Porsche’s adaptive PASM system with four-way KW passive dampers, but for the RS the decision was taken to develop a Manthey semi-active system that would bring about the desired dynamic changes while keeping the configurability for which the RS is celebrated.

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Central to this is a new control unit that adds sensors to monitor the vertical acceleration of each wheel and three sensors reading chassis acceleration, working alongside input signals from steering angle, braking pressure, throttle position, vehicle speed and which gear you are in. Using the data from wheel acceleration and chassis acceleration, the control unit calculates how much damping force is required for each wheel and makes adjustments in real time.

Manthey has further differentiated this car from the standard model by arriving at its own settings for Comfort, Sport and Track modes. This means that selecting Track mode and winding the bump and rebound damping back to -4 no longer yields the most compliance. Instead, Comfort is the softest mode, though as you can imagine, all things are relative. This is a stiff car and no mistake, at least on crumbling UK roads.

But then it’s no shock to find that this is a significantly more hardcore machine than the standard RS: to cope with the added aerodynamic loads, the front and rear spring rates have been increased by 30 and 15 per cent respectively.

The regular car’s configurability remains intact, with suspension, limited-slip diff, stability control and DRS controlled via the same neat array of rotary switches on the steering wheel. Comfort is definitely the least combative setting, but there’s still an uncompromising, fist-like tightness to the damping that sets the tone for an all-consuming experience. Manthey’s mantra is heightened steering response combined with stability, which is exactly what you want around the Nordschleife but not necessarily so crucial on the B660.

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It comes as a shock to discover just how responsive the steering is to your inputs. The slightest movement elicits a direction change, the nose slicing left and right without hesitation. It’s not exaggerated, so a given input yields a proportionate output, but the immediacy either side of the straight-ahead is remarkable. The same goes for the brakes, which have epic pedal feel thanks to new pad compounds plus steel braided brake-lines that reduce line expansion under pressure.

At first you fear the rear has no chance of living with such lightning responses, especially at lower speeds when the wings aren’t working the air so hard, but once you get beyond the unnerving rate of turn-in you find the steering is incredibly accurate and the tail beautifully in-sync and blessed with exceptional traction and lateral grip.

The blend is compelling. British A- and B-roads are not the Manthey RS’s natural habitat – that is undoubtedly the incomparable Nürburgring Nordschleife – but it bosses street use in its own way. Such agility and aggression are beyond the regular RS, and when combined with freakishly precise body control and Porsche’s famed uniformity of control weights, you have a car that genuinely feels like it is connected to you via nerve synapses. I’ve never driven anything quite like it.

Sadly, our drive opportunity didn’t include a racetrack, so we haven’t experienced what 1000kg of downforce feels like through a series of high-speed corners. According to Manthey’s technical project leader for the RS Kit, Jannik Schwark, the lap time improvements around the Nordschleife have come in those sections that were once almost flat now being taken flat-out, and some of the formerly medium-speed sections now being almost flat. If you know the Ring well and have experience of the standard RS, this is a truly knee-knocking prospect. One we intend to experience soon. 

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In the meantime, it’s worth noting that you can still perceive some of the aerodynamic benefits on the road, and also appreciate how they work in harmony with the chassis modifications. Find an empty stretch of dual carriageway, pick your speed and make some lane-change manoeuvres and the Manthey RS feels uncannily planted. No slack, no hesitation, just scalpel-sharp turns. Like skiing with freshly sharpened edges. 

In a nutshell, the faster you go, the better this car feels. Both in terms of how it settles into its damping, and how the downforce supports those dizzying responses by giving you growing confidence in being able to lean on both ends of the car. Even the DRS is more pronounced, a nudge of the steering-wheel button noticeably freeing the RS. Imagine finding you’ve been driving with the handbrake clicked on a notch and then releasing it, and you’ll get the idea. (And yes, I know this requires you to be old enough to remember the days of handbrake levers and not buttons.)

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Manthey Kits can be fitted at the company’s HQ in Meuspath, but the majority are supplied through official Porsche Centres and a select group of independent agents. The work on this car was carried out by UK Manthey agents RPM Technik, who fitted the extensive package of aero, chassis and brake upgrades in the space of a week.

The retro-fit nature of the package affords Manthey more leeway when it comes to the upgrades, simply because it is not constrained by the same efficiencies that dictate how factory-built cars are assembled on the production line. The cost of the 992 RS Manthey Kit is £99,999, plus the cost of the car, which is currently anywhere between £250k and £310k based on the used examples we’ve seen in the classifieds. That’s a lot of money for 500bhp, but, arguably more than with any other car at this level, power alone is no meaningful measure of this machine’s appeal or capabilities.

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Perhaps more than any other high-performance car, the 992 GT3 RS Manthey Kit has been created with a particular objective in mind. Not to the exclusion of all other considerations, but with a special affinity for its birthplace and the 12.3-mile circuit that has come to define the region.

For some, the Nürburgring Nordschleife and the obsession it inspires is beyond comprehension. The Manthey RS is not for them. A truly hardcore machine conceived and executed with a racing mindset, it goes to such extremes that only those who crave the absolute peak of street-legal performance on track – something the factory 992 RS arguably delivered already – will accept the compromises and truly ‘get’ what it’s about.

The extraordinary thing about the standard 992 RS is its ability to balance a race-car-like experience on track with exceptional capability on less-than-smooth roads and in tricky weather conditions. Such focus and duality is unprecedented. Manthey preserves all of the RS’s driver adjustability but moves the needle considerably towards track use. 

Yes, this comes at the expense of ride quality and takes the looks to extremes some won’t wish to go to. Yet hardcore though it is, the Manthey Kit doesn’t ruin the RS for road use. It might look (and go!) even more like a racing car, but it doesn’t sacrifice any more practicality or useability compared with the base car. If you can accept the sharper ride, don’t blanch at the Marvel looks, and buy-in wholeheartedly to Manthey’s approach and status, this RS is a truly extraordinary car. One capable of things no road-legal 911 has ever done before.

Manthey Racing Porsche 911 GT3 RS specs