Manthey Racing Porsche 911 GT3 RS 2025 review – the Nürburgring king on road and track

I may be a Monza newbie, but on my third ever flying lap at ‘The Temple of Speed’ I arrive at the first chicane at about 150mph and bury the brake pedal at the 200m board. The car sheds over 100mph confidently, we snick through the chicane, and the eager flat-six begins building up speed again. 

This morning I wouldn’t have predicted this turn of events, but I’m putting my faith in Porsche track instructor Florin Sutterlin, who’s setting the pace in an identical 992 GT3 RS. In a few laps’ time I’ll swap to the car I’m actually here to sample, the remarkable Manthey Racing 911 GT3 RS MR.

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.

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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.

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.

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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. 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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It seems that every car here is a Porsche but then this is a Porsche Experience event. One of today’s options is hiring a GT3 RS, and while you might think, as I did, that it is an elusive, rare bit of kit, in one overflow car park there are so many that it looks like the back lot of the Zuffenhausen production line. In this context – or any other, to be fair – the GT3 RS MR looks fantastically exotic with its carbon ‘shark fin’ and rear-wheel covers. Mind, you can hire one of them, too.

Most of the stops around here are big ones, but even after seven pretty much flat-out laps, the GT3 RS is showing no sign of feeling the pressure. Its engine still keens for the 9000rpm red line enthusiastically, its Michelin Cup 2s are still gripping resolutely and its cast-iron brakes are not fading or rumbling. Why is every car brought here by Porsche on standard brakes and not carbon-ceramic discs? ‘One trip into the gravel and the PCCBs could be ruined,’ says Sutterlin.  

Back in 2023, Porsche’s Andreas Preuninger and his team were worried they’d gone too far and made the RS too track focused. However, on our 2023 Car of the Year test in cold, wet Scotland – on its Goodyear Eagle F1 SuperSport RS tyres – it was superb, not least for finding grip and dynamic balance where less sportily-tyred rivals struggled. Here at Monza it feels even more at home, remarkably requiring zero attention between 40-minute sessions. What more could you want?

A better question might be ‘what more could you have?’ Did Preuninger & Co leave anything on the table? Manthey concluded there was little scope with the engine, the fabulous, naturally aspirated flat-six having required much attention to meet stricter emissions standards and maintain its 518bhp output. Most would have concluded that there was little scope with the aero either, the front boot having been sacrificed for a centrally mounted radiator, allowing active aero. Proper stuff, with adjustable wing elements at the front and a DRS-style wing at the rear micro-managed in real time by a computer that knows just how much downforce the car can take. 

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The package of components it has developed is extensive and increases downforce from 860 to 1000kg at 177mph without increasing drag. There’s a deeper front splitter and bigger rear diffuser, extra vanes on the trailing edge of the roof, that distinctive carbonfibre shark fin and massive rear-wing end plates, plus the rear-wheel covers, of course. 

Michael Grassl, sales director at Manthey Racing, explains that the carbon rear-wheel discs counteract the effect of the spokes of the upper half of the wheel rotating against the airflow and also help prevent air from the underfloor escaping via the wheel wells, improving the effect of the diffuser and the rear wing. 

The wing and bigger end plates were developed in CFD and proven in the wind tunnel, and the devil is in the detail. Look closely and you’ll spot a small vent in the lower portion of each end plate that releases a build-up of high pressure in the low-pressure zone. There’s also a bite out of each trailing top corner that reduces turbulence – remember the visible rear-wing vortices of old F1 cars in the rain? Meanwhile, the shark fin, or sail, helps stability in high-speed corners and replaces the glass rear screen for a 25 per cent weight saving. 

In addition, the Manthey kit includes increased spring rates, up 30 per cent front, 15 rear, and new dampers with separate bump and rebound valving. They’re semi-active, controlling the ride height and adjusting the damping in 240 milliseconds, and the standard car’s configurability is retained, albeit with a Manthey flavour. The final part of the kit is braided brake hoses. Total price of the conversion? A cool £100k.

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After eight or nine intense laps in the standard GT3 RS, we pull back into the pits and a couple of minutes later I’m trundling down the pitlane in the Manthey RS, selecting Track mode once again. On the short run to the first chicane it feels like rejoining a race after a pit stop, being dive-bombed by a variety of Porsches hauling down from sixth to second gear. A lap and a half later, the tyres of the MR RS – Cup 2 Rs rather than Cup 2s – are warmed up and we are back on it.

A couple of flying laps in and I notice that the MR feels a little more settled in the Varianti Ascari, so I can get on the throttle a fraction earlier with the result that I’m starting to gain on Florin and having to feather the throttle before the brake point. It’s the same into Parabolica and on the start straight. Also, the MR feels very settled through the more open Lesmo 2, slicing across the cuttable inside kerb.

In other respects, the MR feels like the stock RS. Monza is brutal on the brakes but both cars just keep on hitting their brake points, keep finding cornering grip and traction. After half an hour, the only thing that’s feeling the strain is my aching back. I should have bought a HANS device so I could use the full harness belt. Then I notice a puff of smoke from the right rear of Florin’s GT3. And another. Then a brief orange spark of flame. I flash my lights, back off a bit and we both peel off. In the paddock he’s quite unconcerned, explaining that rubber debris occasionally gets flicked up and briefly ignited on the hot exhaust. 

Does the GT3 RS go quicker with the MR kit? I’m not sure if it’s the kit or the stickier Cup 2 R tyres or me getting more confident. Or a combo of all three. I’m also not convinced that Monza is the best place to demonstrate the advantages of the kit; it’s all so smooth and the standard car is easily flat and solidly planted right through Curva Grande, so the additional stability of the shark fin doesn’t tell through there.

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‘We don’t claim any lap time gain,’ says Grassl. ‘It’s the package. It’s about feel. If the customer says, “The car feels better under brakes or better in fast turns but I’m no faster…” we say push harder there then.’ 

Dickie Meaden drove the GT3 RS MR on UK roads (his impressions can be read below) and was blown away by how incisive it was. Track driving is much less about nuance and I’m not sure around Monza I could positively identify the performance uplift. Maybe that’s just me, or perhaps the Nordschleife’s bumpy braking zones would better show off its damping, and Silverstone’s Copse, Stowe or Becketts complex would better demonstrate its high-speed aerodynamic stability. 

The standard car is so good on road and track, finding any gains requires real ingenuity, solutions that almost defy physics, and even if you get there, you still have the law of diminishing returns to contend with. That said, I reckon the Manthey kit is going to make a lot more sense on the upcoming, 750bhp-plus GT2 RS.

Porsche 911 GT3 RS Manthey Racing kit on the road

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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.

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.

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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.

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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.

It’s worth noting that you can 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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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