Development

1957 PORSCHE SPEEDSTER Carrera GT (RS)

Owner: Peter Jon Pearce

The Ultimate Speedster was acquired by Peter Pearce in 1985. It came equipped as a Carrera GT Speedster, although it was not shipped from the factory in that guise (Serial # 82865). It’s presumed that the car was upgraded to Carrera specifications in the late 1950’s for use in SCCA production car racing. When Pearce acquired the car it came with an RS-60 Type 574/5 series 4-cam engine. With the 4-cam engine, Pearce calls the car a Carrera GT RS. With a displacement of 1750 cc, the rebuilt engine dyno-tested at 175 hp. The car was successfully vintage raced from 1988 until 1994. While the 4-cam engine is currently being rebuilt, a pushrod engine was substituted. The car is currently running with the same pushrod engine it ran through 1994. This engine is a 1750 cc engine with about 140 hp and has very low mileage. Since the car was acquired the car has been through several iterations of development.

During the 7-year period (1988 – 1994) Pearce typically ran about 5 races a year, almost all with HMSA. My most notable results included an overall win at 1990 Monterey Historics in Group 3B (GT cars 1955/62, under 2000cc) when the car was running with a 4-Cam Carrera engine. The prior weekend at the 1990 PreHistorics, the car, with Pearce at the wheel, finished first in the races on both Saturday and Sunday. The PreHistorics included all GT cars under and over 2000cc (1955/62). At the 1992 Monterey Historics, Pearce was awarded The Chopard Award for Outstanding Presentation and Performance in his Race Group. This race was for under and over 2000cc with Pearce finishing 5th overall and first in the under 2000cc class. By then the Speedster was running with a pushrod engine after the Carrera engine broke its crankshaft at Sears Point in 1991. The Carrera engine is freshly rebuilt and is being reinstalled shortly. The engine is a Type 547/5, which is the last of the roller crankshaft Furhmann 4-Cam engine series. It was the type of engine used in the Type 718 RSK and RS 60/61 Series Porsche Spyders.

The rebuilt engine includes a new remanufactured roller crankshaft from Karl Hloch in Germany, and verified by Adrian Gang at Edelweiss Porschaus. The original engine rebuild was done in 1990 under the tutelage of the now departed legendary 4-Cam specialist Al Cadrobbi. In addition to the new roller crankshaft, the newly rebuilt engine includes new pistons and cylinders, new valves, and many other new parts. All parts are either new or completely restored. The crankcase was refreshed with machining done by Ross Cummings at Phil Riley & Co., including line boring.

The car is a true dual-purpose sports car that can be set up in full street trim or competition configuration. In street trim, the car comes with a full set of weather protection including new top, side curtains, and a tonneau cover manufactured by Autos International. The interior has also been refreshed with newly upholstered corduroy insert Speedster seats also made by Autos International. The corduroy covered seat and back surfaces in combination with appropriate density cushion foam provide for surprisingly comfortable seating. Pearce has driven the car on 6-hour long trips with minimal fatigue.

In competition mode, the car windshield is removed and a full aluminum tonneau is installed complete with an integral head fairing and wraparound racing screen. These components were custom built to Pearce’s design in the spirit of vintage Porsche Speedsters prepared similarly for competition.

Hidden under the Tonneau is a bespoke removable triangulated roll-cage made from chrome-moly steel tubing designed by Pearce. (Pearce designed and built the structures of Biosphere 2 in Arizona and is an authority on three-dimensional space truss design and engineering.) This triangulated system not only provides rollover protection but also adds significantly to the beam and torsional stiffness. These structural attributes contribute significantly to improved cornering performance.

Cornering performance and directional stability is also improved by reinforced front suspension components with optimized camber and caster geometries. The car is also fitted with an oversize front anti-sway bar and Koni shocks at all four wheels. With the combination of the stiffer chassis, and the aforementioned suspension refinements, the car exhibits remarkably neutral handling. The car is also fitted with AVON radial tires of correct vintage dimensions. Another enhancement that contributes to the cars neutral handling is that it is equipped with an authentic vintage ZF limited slip differential, which works perfectly.

Along with the aforementioned chassis enhancements, the brakes are directly from the Porsche Type 718 RSK Spyder competition car. These brakes are actually somewhat better than the Carrera GT brakes of the period. They are extremely effective in competition. Also, all brake lines are stainless steel.

Other performance enhancements include two external oil coolers mounted in each of the front fenders behind the horn grills. These coolers are positioned as is the case with the original Carrera Speedsters, although the coolers currently installed are of higher performance than the originals. The coolers are controlled by a Porsche factory 904 thermostat.

The car currently has a stock 356 fuel tank installed but a GT style fuel cell is included with the car. The car has been converted to a 12-volt electrical system along with an electronic ignition system. For safety reasons and to protect the car from rust caused by spilled battery acid, the 12-volt battery is installed in a fully enclosed marine style battery box securely mounted to the vehicle bodywork.

Finally, the car was the object of a fully stripped to bare metal restoration and is 100% rust free. The silver paint was refreshed recently as was the interior.