The Manthey Racing team from Germany runs two brand new Porsche 911 GT3 RSR vehicles on 29 July in the 24 hour race on the Belgian circuit. Porsche developed the near-standard racing sportscar based on the road-going 911 GT3 RS and put it in the hands of the experienced team under the direction of team principal Olaf Manthey. Works drivers Timo Bernhard and Marc Lieb (both Germany) share driving duties with Pedro Lamy from Portugal in the GT3 RSR with starting number 111. Driving the Porsche with starting number 197 are factory pilots Lucas Luhr (Monaco), Sascha Maassen (Belgium) with Marcel Tiemann (Monaco).
For Porsche and Manthey Racing the race is regarded as an important test under race conditions and at the same time serves as an assessment of the vehicle‘s present position. For 2006, this race is the only event that is currently planned. For Spa, the car is entered in the so-called Group 2 where vehicles from national championships (here Belcar) are eligible to compete. In 2007, the 911 GT3 RSR will be available for customer racing and aims to continue the success streak of its predecessors. Porsche customer teams claimed class wins in Spa every year since the GT3 first competed there in 2001 – with an overall victory in 2003.
In the FIA GT Championship, the American Le Mans Series and the Le Man Series as well as at the endurance classics of Le Mans, Daytona, Sebring and the Nürburgring, the GT3 in its various versions secured many records and title wins.
Built on the 911 GT3 RS, a particularly light and sporty derivative of the 911 GT3, the current GT3 RSR is designed to comply with the A.C.O (Automobile Club de l’Ouest), the FIA-GT and IMSA (International Motorsports Association) as well as VLN (Veedol Langstrecke Nürburgring) regulations. Porsche decided to build the new GT3 RSR after analysing the relevant A.C.O. and FIA regulations in a specification which allows a minimum weight of 1,225 kilograms (predecessor: 1,125 kgs) and permits the tyre width to be increased by two inches to now 14 inches. 35 kilograms of the required additional weight may be placed as ballast in the vehicle, resulting in a lower centre of gravity.
For the normally-aspirated Porsche engine this specification allows a capacity of 3.8-litres with two 30.3 millimetre air restrictors (predecessor: 3.6-litres, 29 mm diameter). The increase in displacement was achieved through the enlargement of the bore to 102.7 millimetres with the unchanged stroke of 76.4 mm. With the mandatory air restrictors, the unit delivers 359 kW/485 hp at 8,500 revs per minute. Maximum torque increased to 435 Nm. Top engine speed is reached at 9,000 rpm. Thanks to the increase in capacity and the corresponding reprogramming of the electronics the top performance as well as the response and driveability have further improved. The new positioning of the mid-front radiator and the use of side radiators - taken from the high performance Carrera GT sportscar – contribute to the thermal health of the engine.
For the 24 hour race in Spa, the GT3 RSR features the proven sequential six-speed gearbox of its forerunner. The customer vehicles for 2007 will be delivered with a new sequential six-speed transmission featuring the gears of the RS Spyder which competes in the American Le Mans Series.
The bodyshell of the GT3 RSR with the welded-in safety cage is ten percent stiffer than its predecessor. Distinctive wheel arches widen the body by 50 millimetres on each side. The track is enlarged correspondingly; wheels and tyres of the maximum allowable dimension can be fitted.
The relocation of the supplementary oil tank (option), the power steering and the battery to the front improve the weight distribution. The front and rear lids, the front mudguards, the wider rear, the doors as well as the front and rear panelling and wing consist of carbon-fibre composite material. The rear and side windows are manufactured from light polycarbonate.
The newly-developed aerodynamic package improves the aerodynamic efficiency compared to the forerunner (type 996 GT3 RSR) by a total of around seven percent. Airflow to and from the radiators, the brakes and the engine were further optimised. In compliance with the FIA and A.C.O. regulations the new GT3 RSR features a flat underbody.
The suspension with Porsche-optimised struts at the front and the Porsche multi-link axle at the rear corresponds to the configuration of the standard car. The modified kinematics is set-up for the wider tyre footprint and for the lowest possible camber change in rebound and compression. The new ZF-Sachs shock absorbers feature the Through-Rod-System with considerably lower chamber pressure and hence less friction than conventional dampers. As a result they offer a significantly improved response characteristic. The position of the rear axle was optimised. The axle features a new anti-rollbar, an adjustable upper link and an optimised lower link.
The brake system features six-piston aluminium callipers and 35 millimetre thick brake discs measuring 380 mm in diameter at the front and 30 millimetre four-piston aluminium callipers with 355 mm diameter discs at the rear.
Over the 2006/07 winter, 35 units of the new racing sportscar will initially be built.
Technical description: Porsche 911 GT3 RSR (basis 911 GT3 RS, 2006)
- Single-seater, near-standard racing sportscar
- Basis: 911 GT3 RS
- Homologation: Spa 24 Hours Group 2 (national championship), respectively spring 2007 (A.C.O., IMSA, FIA GT)
- Suitable for competition in international GT events
- Not approved for road use
- Coupé, monocoque structure
- Basis 911 GT3 RS
- Lightweight, all-steel bodyshell hot-galvanised on both sides
- Front apron, rear bumper and sideskirts made of carbon-fibre, aerodynamically optimised
- Rear-lid, panelling and doors made of carbon-fibre
- Extended wheel arches made of carbon-fibre
- Side and rear windows made of plastic
- Adjustable rear wing made of carbon-fibre
- Flat underbody complying with A.C.O. and FIA regulations
- Welded-in safety cage (30 metres of seamless steel tubing)
- Racing bucket seat with fire retardant upholstery
- Six-point seat harness, HANS compatible
- Electric fire extinguishing system
- Air-jack system
- Adjustable through rear wing and ride height
Six-cylinder, water-cooled boxer engine, aluminium engine block and cylinder heads, four valves per cylinder, oil cooler with water-oil heat-exchanger, variable valve timing (VarioCam), hydraulic valve-play compensation, intake system with two restrictors each 30.3 mm for A.C.O. 1,225 kg-version, single-throttle butterfly valve, dry-sump lubrication with separate oil tank, oil and cooling water refilling system, exhaust gas treatment: two Metalits with PE Design™, stereo lambda sensor-control, electronic engine management system MS 4.0, six coil electronic ignition, sequential multi-point injection
- Bore 102.7 mm Ø
- Stroke 76.4 mm
- Displacement 3,795 cc
- Compression ca. 14.5:1
- Max. power 357 kW (485 hp) at 8,500 rpm
- Max. torque 435 Nm at 7,250 rpm
- Power output 99.2 kW per litre
- Max. revs 9,000 rpm
- Fuel type RON 98 to RON 102
Exhaust system in the basis version following A.C.O.-spec: Tubular headers with muffler system (113 dB pass-by)
Alternative exhaust systems available:
- Tubular headers following FIA regulations (110 dB standing noise)
- Tubular headers with open exhaust
- Tubular headers with exhaust incl. catalytic converters homologated for DMSB and Spa 24 Hours Belcar category
- 12 Volt
- Motec display with data recording
- Battery capacity 45 A-h
- Alternator 140 A-h
- Bosch Memory Card
- Traction control
- Transmission via dual constant velocity joint driveshafts on the rear axle
- Manual sequential six-speed dog type transmission, “inline“ shift mechanism
- Sensor controlled ignition interruption
- Oil-water heat-exchanger
- Single-mass flywheel with triple-disc fibre race clutch
- Clutch diameter 4.5 inches (114.3 mm)
- Limited slip differential 40/60 percent (or alternative)
- Front axle: Strut type suspension (optimised by Porsche) with unibal joints and corresponding modifications of kinematics, independent wheel suspension on transverse control arms, longitudinal arms and spring struts, double coil springs (master and auxiliary) adjustable in different positions, ZF-Sachs gas pressure dampers (Through Rod System), separated track control arms, adjustable front blade-type roll bar, wheel mounts with double damper clamps, electrically-powered power steering
- Rear axle: Multilink rear suspension with unibal joints and corresponding modifications of kinematics, independent wheel suspension (five arms), rigid suspended subframe, double coil springs (master and auxiliary) adjustable in different positions, ZF-Sachs gas pressure dampers (Through Rod System), separated track control arms, rear axle tie rod strengthened and continuously adjustable, adjustable blade-type roll bar
Adjustable geometry suspension (height, camber, track)
Two-circuit brake system with front/rear circuit separation and brake-power distribution by bias bar system, no ABS, six aluminium monoblock callipers at the front, four-piston aluminium monoblock callipers at the rear, cross-drilled, internally vented brake discs measuring 380 x 35 mm diameter/width at the front and 355 x 32 mm diameter/width at the rear
- Front axle: 11J with Michelin slicks 27/65-18
- Rear axle: 13 J with Michelin slicks 31/71-18
- 1,225 kg following A.C.O and FIA GT regulations
- Power-to-weight ratio: 3.3 kg/kW (2.5 kg/hp)
- Length 4,439 mm +/- 5 mm
- Width 1,957 mm +/- 5 mm
- Height maximum 1,250 mm
Wheel base 2,373 mm
- Front 1,565 mm (3.5 degree camber)
- Rear 1,620 mm (3.0 degree camber)
Tank capacity 100-litre safety fuel cell with quick refuelling system
Quantity for 2007 35
Review 2001 to 2004: the 911 GT3 R/RS/RSR at the Spa 24 Hours
The 911 GT3 in Spa-Francorchamps – undefeated since its comeback
From 2001 the organisers of the 24 hour race in Spa-Francorchamps authorised the return of Gran Turismo vehicles after a break of seven years. Sin ce then, Porsche customers have won their categories every year with various versions of the GT3 – with an overall win in 2003. Porsche supports its teams - staying within the possibilities allowed by the regulations – by lending drivers and providing technical support. Following are highlights of this success story:
2005: Porsche customers score convincing class win
After an eventful 24 hours, the British Gruppe M Racing team celebrated victory in the GT2 category for near-standard Gran Turismo cars with a 911 GT3 RSR manned with works drivers Marc Lieb (Germany), Lucas Luhr and Mike Rockenfeller (both Monaco). During the race the trio had to fight for the title twice: Half-way through the marathon the 911 pulled into the pits for repairs after an accident, took up the race again and reclaimed the lead from the Italian Autorlando-911 after just one hour. Later, when the throttle cable tore in the Porsche driven by Lieb, Luhr and Rockenfeller it took four hours after the pitstop for the three to reappear at the front, from where they never looked back.
Second in the class went to Luigi Moccia, Franco Groppi (both Italy) and Joel Camathias (Switzerland) at the wheel of a 911 GT3 RS run by the Autorlando team, ahead of drivers Christian and Gerold Ried (both Germans) as well as Horst Felbermayr and Horst Felbermayr jr. (both Austrian) in a Porsche 911 GT3 RS entered by the Proton Competition team.
2004: Hat trick for Stéphane Ortelli – Treble success for the German team
A dry and swift race held from 31 July to 1 August ended with three 911 GT3 RSR vehicles entered by the German-based Freisinger Motorsport team claiming a one-two-three class victory.
With their class win with near-standard (N-GT) racing sportscars, Stéphane Ortelli (Monaco), Romain Dumas and Emmanuel Collard (both France) secured third overall. Timo Bernhard (Germany), Joerg Bergmeister (Germany) and Alexeij Wasiliew (Russia) as well as Sascha Maassen (Belgium), Lucas Luhr (Monaco) and Marc Lieb (Germany) followed in fourth and fifth respectively. On their way to victory, the three Porsches beat many of the slightly more powerful vehicles in other categories.
For Stéphane Ortelli this success yielded a hat trick: the Monegasque had also won his category at the Spa 24 Hour race in 2002 and 2003. For all three victories, Ortelli drove a Porsche sportscar run by the Freisinger team.
2003: David conquers Goliath – sensational overall victory against powerful rivals
With a Porsche 911 GT3 RS, the Germany-based Freisinger Motorsport team snatched overall victory in Spa – ten years after the last win for Porsche on the Ardennes circuit. Drivers Romain Dumas (France), Marc Lieb (Germany) and Stéphane Ortelli (Monaco) turned 479 laps with their Porsche and relegated a Ferrari , which started in the GT category for more powerful vehicles, to second place eight laps behind. Third position went to the Seikel Motorsport team which also competed with a 911 GT3 RS.
2002: Class victory for German Porsche team – nine 911s finish in the top ten
The race held on the first weekend in August yielded the first success at the Spa 24 Hours for the Freisinger Motorsport team from Karlsruhe, Germany. Stéphane Ortelli (Monaco), Romain Dumas and Emmanuel Collard (both France) won their class and took third overall at the wheel of their 911 GT3 RS. Eleven laps behind, the second Freisinger Porsche crossed the finish line third in the class followed by seven other 911s.
2001: First event, first success for the GT3 R
The last Porsche race in Spa was long ago: 1993 was the last time a 911 RSR contested the 24 hour marathon in the Belgian Ardennes – and won. After this victory touring cars were not permitted to compete in Spa for many years. In 2001 the organisers opened up the competition again for GT vehicles. Porsche customers came with their 911 GT3 R cars and immediately won the category for near-standard racing sportscars. The winners of this class (N-GT) were Antonio Garcia (Spain), Dieter Quester (Austria), Luca Riccitelli (Italy) and Norman Simon (Germany). First in their class meant fifth overall for the quartet and their 911 GT3 R run by the Austrian RWS team. Positions six, seven and ten went to Porsche customers with their 911s.