Stonegrey

Backdating for pragmatists: no opulent diva on wheels, rather a fun accelerator with motorsport ambitions.

 

When 15 engineers began to put the Carrera RS 2.7 on the wheels in May 1972, one maxim stood in the foreground: the new basis for motorsport should be lightweight and more effective than anything that had gone before. The 50-year success story of the “ducktail coupe” shows that this approach still characterizes automobile construction today. Patrick Zimmermann grew up with the lightweight nine-elevens for the road and the racetrack. Today he feels more committed to this legacy than ever. In his long-established company, dp Motorsport, he creates holistic special bodies that are not only aesthetically pleasing, but almost always light as a feather. The very latest project from Overath-Immekeppel weighs about 1.050 kilograms – without fuel. The basis: a Type 964 from the first years of construction.

 

Overath-Immekeppel, Germany: With the 964 Classic RSR Stonegrey, Patrick Zimmermann shows once again that backdating based on a nine-eleven can also be wonderfully unpretentious. The very latest creation from the Rhineland bodywork specialist is an automotive beauty from next door: not untouchable like a diva on wheels, who is rarely shown out of sheer reverence for her noble features. Rather, the nine-eleven beau of the 964 generation, which looks like a Carrera RSR 2.8 of the vintage, is an extremely handsome fun accelerator. And he is not above letting the purest driving pleasure arise in all situations. Patrick Zimmermann realizes this with a lightweight construction concept, in which not only the long tradition of dp motorsport plays a role. Rather, the sports coupé, which weighs 1,050 kilograms without petrol, is based on a development history that started in 2009 – thirteen years ago. Even then, Zimmermann was able to bring the 911 SC Coupé delivered to one of his customers in 1983 close to the 850 kilogram mark and thus to reach a threshold.

 

When he presented the 964 Classic RSR based on the 964 to the public four years later at the “Techno Classica” in 2013 at the Essen trade fair, he knew: “Even if you use all the tricks and tips, this model will always be a bit heavier than a 911 SC”. What counted for him back then: “On the racetrack, during tourist drives on the Nürburgring-Nordschleife or even on track days, the performance and the overall package are more decisive. That’s why it was important for me to find out whether an additional 25 to 30 hp, ABS and an electronically controlled engine management would not make up for the small weight disadvantage after all.” With the 964 Classic RSR, he came within 150 kilograms of the Lightweight SC. He achieved this – in line with the company’s core competence – by installing hand-made body components made of a carbon-Kevlar mixture. This fabric is extremely tear-resistant, durable and dimensionally stable. It is also used primarily in professional racing car construction. The conversion kit includes the front fenders, the rear side panels, the hoods, aprons, side doors with green tinted Plexiglas and the roof skin. Zimmermann manufactures the components using different processes, always depending on the area to be covered. If this is particularly large, a vacuum method is used, which the master builder describes as follows: “The larger individual parts are still laminated in the classic way and then wrapped in foil to extract the air and allow excess resin to escape. The sandwich core inside is carefully adjusted to ensure the best possible stability over the long term.”

 

For example, dp Motorsport laminates the front fenders and the rear side walls by hand. They create the framework for welded Fuchs forged wheels, in front in 9J x 15 ET 26 and in 11J x 15 ET 15 on the drive axle. KW supplies the individually adjustable coilover suspension with colored anodized top mounts in the “Clubsport” version, which is adjusted to a 40 millimeter lowering. With Michelin “TB5” in the dimensions 225/50 R 15 at the front and 285/40 R 15 at the rear, it would even be possible to take part in sporting events. The naturally aspirated engine with a displacement increase to 3.8 liters delivers 320 hp with a maximum torque of 380 Newton meters. The exhaust system made of stainless steel pipe material with fan headers and two metal catalytic converters contributes to the performance increase of 70 hp compared to the standard version. The interior is defined by the welded tubular steel rollover protection, two characteristic “Lollipop” profile bucket seats and the new exterior paint finish “Stonegrey”. The shifter on the 993 GT2, which is shifted upwards, operates a revised G50 five-speed manual transmission with limited-slip differential.

 

Conclusion: The combination of “Stonegrey” and decorative stripes in „Burgundy Red” creates a new, pleasing color ensemble – the 964 Classic RSR “Stonegrey” is cool, light-footed and, above all, suitable for the race track. In addition to this overall concept, dp motorsport also offers complete bodies in a wide variety of vehicle designs, as well as the sale of almost all individual add-on parts in its own online shop. Possible motto: rather lighter – backdating can be so beautiful and so pragmatic at the same time!

 

Responsible for the content: netzwerkeins GmbH, Carsten Krome

 

964 Classic RSR “Stonegrey” – the technical highlights

Base vehicle: 1989 911 Carrera 2 (type 964), first registered in Belgium

Body conversion: dp-964 Classic RSR made of carbon-kevlar mixture; Lightweight doors with Plexiglas and FIA-compliant sliding windows; green-tinted plexiglass panels glued flush to the body; stripes in “Burgundy Red”

Engine (series): air-cooled aluminum six-cylinder boxer type M64/01

Valve control (standard): one overhead camshaft per cylinder bank (ohc), driven by hydraulically tensioned roller double chain and intermediate shaft; two valves per cylinder, operated via rocker arm

Mixture formation (standard): electronically controlled fuel injection via Bosch DME (Motronic 2.1).

Ignition system (standard): via Bosch-DME (Motronic 2.1) map-controlled dual ignition

Lubrication system (standard): Dry sump lubrication

Oil quantity (series): 11.5 liters

Exhaust system (standard): Lambda-controlled three-way metal catalytic converter

Displacement (series): 3,600 ccm

Bore (series): 100 mm

Stroke (stock): 76.4 mm

Compression (series): 11.3:1

Engine output (series): 250 hp at 6,100 rpm

maximum torque (standard): 325 Nm at 4,800 rpm

Maximum engine speed (series): 6,800 rpm

 

Sports engine: Displacement increased to 3.8 liters and 320 hp with a maximum torque of 380 Newton meters; Exhaust system made of stainless steel pipe material including exhaust manifold set and two metal catalytic converters

Power transmission: Five-speed manual gearbox type “G50” with differential lock, high shift lever type 993 GT2

Electrics: “Liteblox” lithium-ion lightweight battery

Wheels suspension: adjustable KW Clubsport coilover kit with Unibal dome bearings

Wheels and tires: 15″ Fuchs forged alloy wheels with Michelin “TB5” semislicks

Interior: firmly welded roll cage made of tubular steel with door diagonals, belt braces and a cross in the rear; interior painted in the vehicle exterior color “Stonegrey”; “Lollipop” profile bucket seats covered with synthetic leather and Alcantara®; Schroth four-point harnesses; Momo sports steering wheel; lightweight dashboard panels and knee rails; perforated pedal boards including perforated aluminum floor plates