Porsche 911 HLS: The Forgotten Unofficial Prototype

While the history of the Porsche brand is undeniably one of the best-known, particularly thanks to its flagship model, the 911, there is still a certain aspect of this 911 that has been overlooked.

Thus, the story of this forgotten Porsche began in 1966 when the Automotive Design Department at Aachen University had a project to create a coupe racing car with a forward-opening roof. For this project, they used a 1964 Porsche 911 904 as a basis. However, inspiration was drawn from the Porsche 904 racing car and its rear engine cover, which could be considered a kind of retractable roof. This 911 would be called the 911 HLS "Klappdach" (folding roof in German) Rennsport coupé.

The designers and outliners of this project quickly established a line and a 1:8 model was made before a full-scale model was assembled by "sacrificing" the 1964 911. The model is very different from the 911. In order to maintain a light weight, a true perpetual quest at Porsche, many parts including the rear hood and the "Targa" roll bar are made of aluminum. While the chassis, the engine and the characteristic "houndstooth" seats come from the 911, the opening system is unique in the history of the brand: a large dome fixed to the front and tilting upwards, with an opening angle large enough to allow entry and exit of the vehicle without effort. For reasons of rigidity and stability, the side members are reinforced and the door sills are higher than on other cars (a bit like on the most recent BMW Z1). The project's decidedly sporty ambitions are visible through the dashboard instruments transferred to the right side of the car (5 locations). The rearview mirror is ogive and resembles that of the 904.

The major innovation lies in the articulated canopy forming a harmonious body profile.

The engine was positioned at the rear, near the rear axle. It was the same as the 1964 Porsche 911, a 2.0-liter flat-6 developing 130 hp.

Inside, the interior features a sporty feel with a rather unusual dashboard: on the driver's side, there's the steering wheel and a few buttons on either side. On the passenger side, a set of five dials oriented toward the driver takes up a large space.

The car is a true 4-seater, with rear seats with folding backrests. The front seats are quite simple and not at all sporty. They are leather-clad with a central section featuring a black and white checkerboard pattern.

Once the prototype was completed, it was sent to a body shop in Würselen (a small town in Germany) who gave the model its green color and also added the black HLS letters to the side of the vehicle.

The sequence of events probably explains why this project fell into oblivion. We assume that this rather eccentric design was not appreciated in the Porsche offices. A very bad fate awaited this unique Porsche. It was left to its own devices outside the body shop where it was completed for over 40 years. It was only when Manfred Hering of the Early 911S website was consulted about restoring this forgotten project that the 911 HLS was given a second life. "I was asked if I could restore this Porsche with a budget of 30,000 euros. I declined the offer, but then I tried to buy this unique Porsche," says Hering. "After three years of discussions and negotiations, I got my hands on this piece of history. The original engine was in pieces, but was included in the sale."

Hering has specific plans for the car's future. In April 2015, he presented the Porsche with the retractable roof for the first time at the Techno Classic. He then began its restoration.