Porsche 992 GT3 RS vs Manthey Racing Kit: How Much Faster Can It Get?

Introduction

Few performance cars arrive with a reputation as complete as the Porsche 992 GT3 RS. It has been called the best road and track car money can buy, and it earned that status with a combination of raw pace and everyday usability that very few rivals can match. The obvious question is where you go from there. Porsche’s racing partner Manthey Racing has an answer: a Porsche-proven upgrade package costing around 100 grand before fitting, focused entirely on aero and chassis. We compare the two to find out how much quicker the kit actually makes the car, and whether it is any good to drive on circuit.

Manthey’s credentials are not in doubt. The team has raced 911s for decades and factory Porsche GT cars since 2013, winning at Le Mans and the Nürburgring repeatedly along the way. If anyone can make the RS even more capable, it is this outfit.

Porsche 992 GT3 RS: The Benchmark

The standard RS is the starting point, and what a starting point it is. Everything about it feels honed for a lap time, yet it remains a joy just to drive, with a hooked-up feel that inspires enormous confidence. Adjustability is everywhere: dampers offer separate bump and rebound settings front and rear, and the differential can be tuned for entry mid-corner and on power exit. The modes let you fine-tune rather than reinvent the character.

The naturally aspirated engine revs all the way to nine thousand, and the car feels like a race car for the road in the best sense. Interestingly, it does not feel wildly quick in a straight line. That actually enhances the sense of corner speed, because you arrive at corners, brush the brakes, and carry all your speed in rather than stopping and starting like a normal road car.

In isolation it is hard to imagine how a road car could be more capable on a circuit. That is exactly the challenge the Manthey kit sets out to answer.

Manthey Racing 992 GT3 RS: 20 Percent More Downforce

The strange thing about the Manthey car is that everything is fundamentally the same, yet everything is different. Manthey followed the same route the factory did, unlocking more front downforce by routing air through where the luggage space was, which in turn enables that enormous two-element rear wing. Dive planes, a bigger and deeper splitter, and more efficient airflow over the body add more still. The rear window is gone, replaced by a giant fin for high-speed stability.

The headline number is roughly 20 percent more downforce. Under the body there is an extra front panel sealing from the back of the splitter to the main floor, and a diffuser that is both deeper and longer. Remarkably, the package is drag neutral: because it must stay within homologation paperwork, the car will not go any faster or any slower in a straight line than the standard RS.

Mechanically, nothing has been touched. The engine and gearbox are identical, and the drag reduction system software works the same way. All the gains come from wringing more out of the tires and exploiting the extra aero through corners.

How the Manthey Kit Feels on Track

Manthey’s philosophy is to give the driver as much confidence as possible. Rather than swapping the adaptive dampers for fixed units as it has done historically, Manthey kept the standard suspension architecture but added its own controller and more sensors, making the system smarter and more responsive. Each wheel adjusts in real time, and there are more distinct modes, from the softest comfort setting to a track mode with far more adjustability. Brake pads and brake lines are also upgraded.

On the road, the Manthey car is immediately stiffer than the factory car. On track, with more load in the chassis, it settles into itself and the differences are harder to detect. Tested in track mode on the suggested starting settings of zero bump and rebound front and rear, the front end grip is improved, with aero balance shifted slightly forward, between 1 and 2 percent. Crucially, the rear always supports the direction change, so the sharper front never leaves the car feeling unstable.

The improvements are fine marginal gains, painstakingly found in a car that already had everything squeezed from it. That is inevitable given the shared mechanical base, and it is why the subjective differences are easier to detect than the raw lap time delta.

Lap Times and Verdict

Both cars were timed on Michelin Cup 2 R tires, the most aggressive rubber in the range, with plenty of time to bring the tires into their operating window. After brimming the tanks and weighing both cars, the Manthey car was a tiny bit heavier but still very close to Porsche’s official figure with a 90 percent full tank.

The standard RS set a 1:11.1 lap, an impressive time that matches a McLaren 765LT. The Manthey car then went a fraction quicker than a 1,000 horsepower Ferrari SF90 with the Assetto Fiorano pack on the same tires, making it the second fastest road car ever timed on this 1.5-mile coastal circuit. Only the single-seat, roofless BAC Mono 2.5 is faster. For a full road car with a boot that legally seats two, that is an extraordinary result.

Is the 100 grand worth it, plus fitting? It is a huge amount of money, and you could buy some genuinely special cars for that price. But improving a car already at such a high level may genuinely require that kind of spend. The gain is meaningful, the car is enjoyable everywhere you drive it, and the kit was really born for the 12-plus miles of the Nürburgring, where its extra confidence and downforce change your perception of every corner.

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Conclusion

The 992 GT3 RS remains the benchmark, and the Manthey kit does not replace it so much as elevate it. If the standard car already feels like the limit, the Manthey package raises that ceiling everywhere: later braking, more mid-corner speed, earlier power application. It is not an engine or gearbox upgrade, and it will not win any drag race, but as a track-focused investment for a car used as intended, it is a meaningful and remarkably usable gain. For buyers chasing the very last margin of road-legal circuit performance, the Manthey version is the one to have.