The Porsche 550 Durlite Spyder is a car that was built on the remains of a crashed Porsche 550 Spyder. One year after the crash, contemporary American aeroplane aerodynamicists Durlite created the odd looking Porsche 550 Durlite Spyder with the streamlined nose. The owner of the car Bob Webb had an obsession with airflow, so he had Durlite create a cheese-wedge bodyshell with snipped-off Kamm tail that not only looked far more dramatic than the existing 550 Spyder. All this made sure the car produced far less frontal lift – though that was only quantified half a century later in a rival manufacturer’s wind tunnel.
Even though Bob Webb was an experienced racer he crashed the Porsche on its first outing. Rather than buy new parts to restore the Porsche to its original format, Bob Webb went on the experimental route, with the company’s permission and a 1600 Porsche RSK engine was installed.
The wheels, brakes, front suspension derive from the standard Porsche 550 Spyder. The rubber came from Dunlop with 500L-15 on the front and 550L-15 at the rear. Even though back in the days the drum brakes were standard, the brakes were later converted to more modern brakes, but not without keeping a small eye on originality.
The ducts in the nose are for cooling the front brakes, and the raised section of the engine cover is designed to allow maximum air supply to the carburettors. The lips of the rear wheelarches are flipped out to avoid cutting the tyres while cornering. The bodywork always was unpainted bare aluminium, and the fixings are all period fasteners. Up front, there’s a very small subframe in the nose of the car and the air intake for the oil radiator is situated here, while brake ducts channel air straight onto the drums. It’s all very neat, yet actually very simple. The headlights are unrelated to the 550 but do the job, and the steering wheel, mirrors, switchgear and instrumentation are suitable period items.
The oil tank is to the right of the cockpit because it’s a dry sump engine, and the fuel tank is ahead of the cockpit and to the right-hand side, which, with the driver’s weight to the left, helps the balance of the car. The roll-over bar was modified the bar to accommodate the seat harness. The wraparound perspex windscreen has little rake to it, but the passenger side of the cockpit can be covered over by an aluminium tonneau cover which helps airflow.
A interesting and important aspect is that the new body was much more aerodynamic than the original Porsche 550 Spyder. So how good was the Durlite design? The answer came not from Weissach nor Durlite themselves, but from Audi, curious to make comparisons with evolving aerodynamics and drag coefficients. The restorer says: ‘Audi came to us, saying they’d heard that we’d restored the car, and they asked if they could put it in their wind tunnel. At first we thought they were joking. Because after all, it is a Porsche. Perhaps they were interested to see how the aerodynamics of a car designed 50 years ago compared with the R8. Audi engineers were stunned to find that the nose did not lift until the theoretical road speed hit 308kph (191mph).’ Sadly, what we don’t have is a record of how Bob Webb fared with it during its race career in the early ’60s, though with an RSK powerpack in a whippy chassis it must have been interesting, to say the least.