Guide: Renn Sport Spezial - a Historical & Technical Appraisal of the Porsche 911 3.6 GT3 RS Strasse (996.2)
BACKGROUND
Having made its debut during the early part of 1999, Porsche’s 996-based 911 GT3 R, along with its subsequent RS replacement, became the dominant force in the junior categories of a revitalised GT racing scene.
Initially, competition for Porsche’s satellite and privateer teams was limited, but over the next couple of seasons significant new threats emerged, most notably from Ferrari (with the Michelotto-developed 360 GT that won the FIA GT Championship N-GT Team and Drivers’ title double in 2001) and BMW (with the E46-based M3 GTR that won the 2001 American Le Mans Series’ GT category).
Nevertheless, with five straight class wins at the Le Mans 24 Hours (1999 through 2003), a trio of American Le Mans Series Team Championships (2000, 2002 and 2003) and a brace of FIA GT Championship N-GT class Team and Driver titles (2002 and 2003), there was little doubt the 996 GT3 had proved itself the dominant entry level GT racing car during the early 2000s.
Despite the imminent arrival of an updated 997-type 911 set to be unveiled during the autumn of 2004, a version for international GT racing was not expected to hit the track until early 2006. Accordingly, Porsche went on to create a third iteration of the 996-based GT3 to replace the GT3 R and RS for the ‘04 and ‘05 seasons.
That car was appropriately dubbed the 996 GT3 RSR and ushered in a number of updates to include an even more powerful 455bhp engine and, for the fist time, a sequential gearbox. In addition, significant suspension and aero updates were required along with a weight reduction programme which meant Porsche had no option but to launch a new road-going base car in order to meet homologation requirements.
The resultant 996 3.6 GT3 RS Strasse (officially dubbed the 911 GT3 RS) was unveiled at the Frankfurt Motor Show in October 2003.
A further evolution of the existing 996.2 GT3 launched at the Geneva Motor Show in March 2003, this latest iteration of the Renn Sport theme was the most hardcore production-based 911 for many years. It was in fact so focused that several road testers considered the RS too extreme for normal road use.
By way of an homage to Porsche’s original 911 Renn Sport (the 2.7-litre Carrera RS of 1972 / ‘73), the GT3 RS was offered exclusively in Grand Prix White with either a red or blue decal kit and matching wheel centres. Meanwhile, as per the original 996.1 GT3 (but not the 996.2 GT3), the RS was not offered for sale in North America. On this occasion it was because the RS rollcage necessitated deletion of the normal side airbags.
Production got underway in late 2003.
CHASSIS
The most significant difference to the GT3 RS chassis over a standard GT3 concerned its suspension.
For new uprights and mounting points to be homologated on the RSR (to improve turn-in, lessen bump steer and reduce tyre wear), the RS came with adjustable and reinforced top mounting points, front uprights with twin instead of single clamp bolts (to which the anti-roll bar links were attached as opposed to via a separate bracket welded onto the strut body), new wheel hubs with strengthened carriers for improved camber control, adjustable control arms and optimised rear axle geometry.
Stiffer progressive instead of linear springs were fitted and the damper settings re-tuned accordingly.
Ride height was lowered by 3mm.
18-inch diameter wheels were shared with the standard GT3 (8.5-inches wide front and 11 at the rear), but they automatically came with painted centres (in red or blue) and were shod with the latest Pirelli P Zero Corsa tyres instead of Michelin Pilot Sport items (235/40 front and 295/30 rear).
As per the standard 996.2 GT3, each RS was based around the contemporary Carrera 4’s galvanised steel bodyshell which was modified to incorporate custom mounting points for the engine and gearbox. Compared to the Gen. 1 shells, these later Gen. 2 monocoques had undergone extensive reinforcement of the roof frame, sills and seat pan area which yielded torsional stiffness gains of 25%.
Left-hand drive cars came with a long-rang 89-litre fuel tank while right-hand drive examples were fitted with a smaller 64-litre item.
Suspension was via MacPherson struts up front and a multi-link arrangement at the rear.
Compared to the first generation 996 GT3, all 996.2 versions featured uprated front brakes with the original 330mm discs and four-piston calipers switched to 350mm items with six-piston calipers. 330mm discs with four-piston calipers were retained at the back. As usual, the calipers themselves were finished in high gloss red paint.
ENGINE / TRANSMISSION
As a consequence of the additional time and cost involved with gaining type approval for a significantly enhanced engine, Porsche officially quoted the RS as having the same 375bhp as a regular 996.2 GT3. However, this was admittedly developed at 100rpm less than before (7300rpm as opposed to 7400rpm) owing to a bigger air scoop under the rear spoiler that generated greater ram effect.
In reality, it is understood that, thanks primarily to re-shaped intake and exhaust ports (along with the ram effect air collector), the RS produced closer to 400bhp.
The engine type number was unchanged: M96/79.
Like both the 996.1 and 996.2 versions, this latest GT3 used Porsche’s special Hans Mezger-designed engine which was very different to regular Carrera motors.
Among its long list of unique characteristics, GT3 engines had a bigger bore and shorter stroke which made them much more responsive than the Carrera engines offered alongside.
GT3 engines also came with a low friction valve train plus lightweight forged pistons and titanium connecting rods that allowed them to rev much higher. A nitride-hardened lightweight crankshaft with eight bearings was another feature.
In order to accommodate the long block Mezger power unit in the 996 engine bay, Porsche Motorsport had devised a GT3-specific dry-sump lubrication system with the oil tank mounted on the engine block.
Custom-mapped Bosch engine management was configured to the Mezger engine’s characteristics and the compression ratio was markedly higher than the Carrera (11.7:1 as opposed to 11.3:1).
Compared to the M96/76 engine in the 996.1 GT3, the updated M96/79 fitted to the 996.2 GT3 featured lightweight pistons, con-rods, valves and tappets, a drive-by-wire throttle, a free-flow exhaust system and the latest Bosch ME 2.8 engine management with sequential multi-point fuel-injection. The crankshaft damper was deleted in the quest to save weight and the engine was allowed to rev higher than before. Overall, the M96/76 motor came out 3.5kg lighter than its predecessor.
Otherwise, the engine’s basic characteristics were carried over: it was another water-cooled all-alloy Flat 6 with dual overhead camshafts per bank, four valves per cylinder and a VarioCam dual-stage intake system.
Displacement was 3600cc (thanks to a bore and stroke of 100mm and 76.4mm).
Uniquely, the RS featured a close-ratio version of the Getrag G96/96 six-speed manual gearbox fitted to the base GT3 along with a single mass flywheel.
GT3 gearboxes were essentially updated versions of the reinforced units found in the 993-type 911 GT homologation special. They came with triple-cone synchros on every gear and used steel pieces on second through sixth which offered much greater wear resistance compared to brass components.
Transmission was through a reinforced clutch and mechanical limited-slip differential.
No traction control system was employed and nor was the Porsche Stability Management system.
BODYWORK
Aside from the GT3 RS script emblazoned down each flank and those aforementioned colour matched wheel centres, the RS came with a number of bodywork features that differentiated it from a regular 996.2 GT3.
To improve cooling, a trio of vents were carved from the trailing edge of the front bumper assembly.
Further back was a new rear spoiler left in exposed carbonfibre. Mounted underneath was the bigger air scoop discussed earlier.
Unlike the base GT3, the RS had a front lid, complete engine cover / spoiler assembly and exterior mirror casings fashioned from carbonfibre.
The weight-saving theme continued with a plastic rear window and the metal front badge normally fitted was switched to a decal.
The remaining body panels were steel with the exception of the bumpers and sills which were formed from plastic composite.
Only one colour was offered: Carrera White with red or blue wheel centres and graphics.
INTERIOR
Inside, the RS was to more-or-less the same Club Sport specification available on the regular GT3, albeit with a more extensive rollcage that had been reinforced with an additional rear crossmember.
As per the M003 Club Sport option, the RS came with fire-proof Nomex fabric for the Recaro bucket seats, six-point Schroth harnesses, preparation for an electrical cut-off switch and a fire extinguisher in the passenger footwell.
Equipment unique to the RS included a steering wheel rim, gear lever and handbrake handle trimmed in alcantara suede. The steering wheel stitching and seat belts were colour matched to the exterior decals and wheels.
The rest of the RS interior was identical to the 996.2 GT3 which meant it came with all the cockpit updates ushered in for the regular 996.2 Carrera to include a lockable glovebox, matt as opposed to gloss-finish switchgear, seatbelt tensioners with belt force limiters, a larger central air conditioning vent and the more comprehensive onboard computer from the Turbo.
Behind the steering wheel was a traditional five-gauge dash with a centrally mounted 9000rpm rev counter specific to the GT3. Off to the left was a speedometer and voltmeter while on the right was a combined oil temperature / fuel gauge and an oil pressure dial. Digital read outs at the base of the three main instruments provided the driver with all manner of additional information.
The remaining switchgear was mounted on the central console along with the ventilation controls.
To reduce weight, all GT3s came with a simplified interior compared to the regular Carrera.
The rear seats were deleted and the vacant area carpeted instead.
Sound deadening was much reduced, manual instead of electric mirrors were installed, the lower section of the central control panel was removed and no audio system was fitted.
Underneath the front lid was a space-saver spare wheel.
Single-piece fibreglass-shelled Recaro bucket seats could only be adjusted fore / aft.
GT3 branding was applied to the rev counter, carpeted rear bulkhead panel and sill plates.
Electric windows, remote central locking and an alarm / immobiliser were standard in all markets.
Air-conditioning and an audio system could be re-instated at no additional cost.
OPTIONS
The list of optional extras available on the GT3 RS included Porsche Carbon Ceramic Brakes (PCCB) which offered increased stopping capacity and a weight-saving of 17kg compared to a standard steel disc set-up.
Customers could also specify certain interior surfaces to be painted body colour along with aluminium or carbonfibre inserts. A variety of audio systems were available should the owner wish for one to be installed.
WEIGHT / PERFORMANCE
Thanks to its variety of weight-saving measures the RS tipped the scales at 50kg less than a regular 996.2 GT3 (1330kg as opposed to 1380kg).
Top speed was unchanged at 190mph, but 0-62mph was a tenth quicker at 4.4 seconds.
END OF PRODUCTION
RS production ran from late 2003 until mid 2004 by which time 682 had been completed, 140 of which were right-hand drive.
Four cars were completed in 2003 with the remainder built during 2004.
COMPETITION HISTORY
During the course of two seasons, the Gen. 2-based 911 GT3 RSR swept aside the challenge from Ferrari to win every major honour on offer.
The N-GT class of the 2004 FIA GT Championship fell to Sascha Maassen and Lucas Lohr (Freisinger Motorsport) while the 2005 title was claimed by Marc Lieb and Mike Rockenfeller (GruppeM Racing).
The GT class at the 2004 Le Mans 24 Hours went to Jorg Bergmeister, Patrick Long and Sascha Maassen (Petersen-White Lightning Racing). The following year, Mike Rockenfeller, Marc Lieb and Leo Hindery took the class win (Alex Job Racing).
The Alex Job Racing team were also crowned 2004’s American Le Mans Series GT class champions. They were succeeded by Petersen-White Lightning Racing in 2005.
Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com
