Porsche has just unveiled the new Porsche 911 GT3 RSR, an extensively modified motorsports version of the Porsche 911, powered by a normally aspirated 3.8 litre boxer engine and a 6-speed sequential gearbox. It weighs approximately 1,225 kg complying with A.C.O. regulations, and 1,200 kg complying with FIA regulations.
The 6-cylinder boxer engine is an all-aluminium unit that makes its 465 horsepower at 8,000rpm, but the rev needle goes all the way up to a maximum engine speed of 9,400rpm, approaching superbike territory. Each cylinder has a bore of 102.7mm and a stroke of 76.4mm. Peak torque of 430Nm which exceeds the usual 100Nm per litre ratio is achieved at 7,250rpm. The engine uses dry sump lubrication, individual throttle butterflies, and requires RON 98 fuel.
The transmission is a 6-speed sequential with a jaw-style shift. The gearbox was developed with the know how gained from the RS Spyder sports prototype. The gearbox features a oil/water heat exchanger, a single mass flywheel, a hydraulic disengagement lever, a three-plate carbon-fibre clutch, and a 45:65 LSD. It is considerably lighter than its predecessor with reduced internal friction, and the flat angle of the drive shafts allow racing teams a wider range of suspension settings.
The GT3 RSR suspension consists of McPherson strut design at the front with Sachs four-way gas pressure dampers, double coil springs (main and ancillary spring), camber adjustable front axle arms, and an adjustable swordtype anti-roll bar on both sides. The rear suspension uses a multi-arm axle with rigidly mounted axle sub-frame, Sachs four-way gas pressure dampers, double coil springs (main and auxiliary spring), a reinforced and an infinitely adjustable rear axle tie-bar. The suspension is infinitely adjustable in the height, camber and track variables.
Brakes are single-piece six-pot aluminium fixed calipers at the front with 380mm discs and racing brake pads, while the rear uses 355mm discs with four-pot calipers. Wheels are three-piece BBS light-alloy wheels measuring 11J x 18-34 at the front and 13J x 18-12.5 at the rear.
The race-spec body of the GT3 RSR is made of hot-galvanised steel. The front bumper, underfloor and rear wing are aerodynamically optimised. It uses a fast filling function for the 90 litre safety fuel tank. On the inside there is a welded-in roll cage, a bucket-type racing seat on the driver’s side with a flame-resistant seat cover, a six-point HANS seatbelt, and an electric fire-extinguishing system.