Official photos: 991.1 2015 March 3, 991.2 2018 February 21 Premiere: 991.1 2015 March 3, 991.2 2018 March 6, both at the Geneva motor show (Salon International de l'Auto et accessoires) press day Market launch: 991.1 2015 May, 991.2 2018 April
Technical specification and comparison
2018 911 991.2 GT3 RS 4.0
6:56,4 Michelin Cup 2 R
2015 911 991.1 GT3 RS 4.0
7:20 Michelin Cup 2
2017 911 991.2 GT3 4.0
7:12.7 not stock
2013 911 991.1 GT3 3.8
2011 911 997 GT3 RS 4.0
The RS has been mostly a cosmetic evolution of the non-RS GT3 already since the 996 generation and that is the case also with the 991 GT3 RS 4.0. The purpose of the front fender air vents is to give more downforce to the front axle, but no such vents have been used on the 991 GT3 Cup or RSR, so they are probably more show than go. The side air openings (with their initial purpose of cooling the intercoolers in the turbo-engined car) are used for the intake air. For its 1.4"/36 mm wider body, 2"/50 mm wider track at front, 1.2"/30 mm wider track at rear, larger wheels (0.5" wider front and rear, 1" larger diameter at rear) and standard roll cage, the RS has only slightly more power to compensate all that. The gear ratios of the RS have been chosen more for the race track use instead of top speed and that is the reason the RS accelerates better than the standard GT3. The gear ratios and less aerodynamic body mean the top speed of the RS is slower than that of the regular GT3 with less power.
The wheels and tyres measure exactly the same as on the 918 Spyder: fronts are 9.5x20" with 265/35 tyres and rears 12.5x21" with 325/30 tyres. Such a selection for the wheels for the RS is not for its benefit as all Porsche racing cars use 18" wheels to keep the weight down and have the best braking performance.
The front lid, front wings and rear lid are made of CFRP (carbon fibre reinforced plastic) and the roof is constructed using magnesium.
At the beginning of time 'RS' standed for 'Rennsport' which means 'racing' in German. The 'RS' in the Porsche name used to mean it was a street legal racing car. Think of a 991 GT3 Cup with minimal equipment to make it street legal. That is not the case with the 991 GT3 RS. Like the 991 Turbo and the 991 GT3, the 'RS' is full of stuff that is not put into real racing cars.
Comparison with the racing car
991 GT3 Cup
991 GT3 RS
Brake discs front / rear
380 mm / 380 mm
380 mm / 380 mm
Porsche Torque Vectoring
PASM electronic damping control
1175 kg / 2590 lb
1420 kg / 3130 lb
Conclusion: the 991 GT3 RS is an absolutely amazing car, but it is not what a street legal 991 GT3 Cup could be.
991.1 GT3 RS
Although expected, the engine size was not increased for the facelift model - mostly because of technical limits and maybe also because of the CO2 emissions. Maximum engine speed was rised from 8800 to 9000 rpm and power from 368 to 383 kW. Its wide and sort-of-troubled exterior design means in top speed the 991.2 GT3 RS 4.0 cannot beat the slicker and more aerodynamic non-RS version, not even the 991.1 GT3 3.8.
The optional Weissach package was more of an optical package than a racing package. While the Clubsport package came with steel roll cage that could be extended at the front for motorsport use, the lightweight titanium roll cage in the Weissach package was not approved for racing, its use was limited to track days. But that's the purpose of the GT3 RS. The Weissach pack included additional carbon components for the chassis, interior and exterior, as well as optional magnesium wheels from 918 Spyder.
Nürburgring Nordschleife lap time 6:56.4
With its soon-to-be-launched Pilot Sport Cup 2 R tyres Michelin proved that even the already best street legal tyres can be enhanced further. On April 16, 2018, the 383 kW 991.2 GT3 RS fitted with Weissach package, magnesium wheels, Cup 2 R tyres and driver Kevin Estré managed to lap the Nürburgring Nordschleife in 6:56.4. Remember, the 652 kW 918 Spyder has lapped the Nordschleife in 6:57. The result of the 991.2 GT3 RS sounds unrealistic compared to the 7:20 lap of the 991.1 GT3 RS (which has just 15 kW less power), to the 918 Spyder or the 515 kW 991 GT2 RS that is just 9 seconds faster on this 12.9 mile/20.8 km ring.
Considering the CO2 emissions of the normally aspirated 4-litre 9000 rpm engine - which are 200+% over the EU 2020 regulations - the 991.2 GT3 RS is the last of a kind. It remains the most powerful naturally aspirated street legal Porsche of all times.