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June 08, 2012
One glance was enough to know exactly what the superbly proportioned sporty two-seater was meant to build on: there were increasing calls from customers for a roadster that would continue the legacy of BMW’s legendary sports cars of the past. The 328 and 507 had long since gone into the history books as sporting and style icons, and there had been nothing to take their place for several decades. It was time to fill the gap with something right up to date. As the press release stated: “BMW Technik was commissioned by the Board of Management of BMW AG to devise and execute a vehicle concept which would largely satisfy the desire for ‘freedom on four wheels’, driving pleasure and performance.” The fundamental driving experience should clearly take precedence, rather than adopting the comfort-focused approach that prevailed in competitors’ sports car concepts throughout the 1980s. “Young”, “dynamic” and “brash” should be the words that best described the Z1, along with “a new dimension in driving”. Trademark BMW roadster attributes were adopted and fused with the latest technology. Ingredients included superior performance, the ability to drive with the roof down, a sense of sheer originality and a dash of extravagance. The Z1 had all the right credentials: low weight and low centre of gravity, front mid-engine and compact dimensions. The highlight though was without doubt its pioneering technology: the unique vertical sliding door concept and the supporting sheet-metal structure with a plastic outer skin.
Demand wins the day: the roadster is to be built – by hand
The response was overwhelming – the company was inundated with inquiries from customers, while there was a great deal of public speculation about whether BMW had the courage to actually build the car. Whereas BMW kept silent on the matter, development for series production was already in full swing behind closed doors. It was obvious that the Z1 would have to be built largely by hand on account of its unusual design characteristics and the materials used. This, in turn, meant a small production run and a high price tag. Nevertheless, the BMW Board of Management pushed ahead with the launch.
Almost exactly two years after finalising the Z1 concept and one year on from the study’s unveiling, BMW laid its cards on the table when it made the following announcement on 10 August 1987: “The time for speculation is over, the guessing game has come to an end: BMW AG will be presenting the Z1 Roadster at the Frankfurt Motor Show.” Speeding up the development process had been a pilot task for this project, and after a development time of just three years a limited number of the 170 hp front mid-engined sports car would go into small-scale production from June 1988. “Once the custom-built production process is up and running at full capacity, up to six car enthusiasts a day will be able to start enjoying undiluted driving pleasure instead of just dreaming about it.”
The ink had barely dried on the announcement when the advance orders started to stream into Munich. The Frankfurt Motor Show hadn’t even started when a major motoring magazine wrote: “The groundswell of euphoria gives reason to suspect that the last person to place an immediate order won’t get their hands on their Z1 until the year 2000!” BMW gave a small group of top journalists a preview of just what would make the new roadster one of a kind. The Director of BMW Technik GmbH at that time, Ulrich Bez, gave an emphatic demonstration of the benefits of the plastic panelling: he jumped with both feet onto a vehicle wing lying on the floor, which promptly buckled – then sprang back to its original shape when he stepped off it again.
Unequalled even today: vertical sliding doors
Viewed from the outside, the Z1 therefore had all the makings of a sophisticated-looking, but ultimately conventional roadster – if it hadn’t been for its doors. These retracted electrically into the side sills, allowing both driver and passenger to cruise along with the door open if they wished, a feature which has never been emulated since. “The car is so low and the flanks so deep that the driver of the new model is able to effortlessly pluck sweet clover, plantains and other ground-hugging greenery from the wayside by simply leaning out,” as one news magazine reported. What’s more, this particularly refreshing form of travel was both perfectly safe and legal into the bargain thanks to the ample side protection provided by the high sills.
The mechanism for the doors and side windows was driven by two electric motors and a toothed belt. The motors incorporated a freewheel function to allow the doors and windows to be operated manually if necessary. To avoid burdening the actual door with additional weight, all of the electrical and mechanical components were integrated in the car’s body. A double mechanical lock acting on the doors in both opened and closed position prevented rattling noise and excessive door movement while driving. The side windows could, of course, be lowered separately from the doors: after the doors had been opened and closed again, the windows automatically returned to their previous position.
Low centre of gravity, broad stance: “supreme driving pleasure”
The powertrain and chassis of the Z1 were largely inherited from the 3 Series. Hard at work under the bonnet was the classic BMW straight-six engine, which mustered 170 hp from its 2.5-litre displacement and was fitted in a front-mid position. A central aluminium tube ran from the five-speed manual gearbox to the rear differential to produce a torsionally and flexurally rigid link between the two. The single-joint spring-strut front axle taken from the 3 Series handled the task of wheel location at the front, but a brand new construction was employed at the rear: a multi-link axle comprising two transverse control arms and one longitudinal control arm. It was dubbed the “Z-axle” in German, which was shorthand for “centrally guided, spherical double-wishbone axle” rather than a reference to the new model’s name. The kinematic arrangement of the three control arms ensured excellent directional stability as well as effective anti-squat and anti-dive control. This configuration endowed the Z1 with go-kart-like handling characteristics, with the axle load split in the ratio 49:51 and the vehicle’s centre of gravity located some ten centimetres lower than on comparable sedan models.
As a result, the Z1 was truly in its element as it wound its way along the twisting country roads of Central Italy around Punta Ala, earning it unanimous praise. It was deemed to offer “supreme driving pleasure” and revered as a “textbook driver’s car”. As the assembled international car testers at the presentation noted to their surprise, not even the poorer roads could trouble the chassis or provoke any tangible body torsion. The Z1 had a top speed of 225 km/h (140 mph) and could dart to 100 km/h (62 mph) from stationary in just under eight seconds. “For the Z1 driver, it is not the sheer performance that makes the compact car so appealing,” as one well-known tester reported, “rather it is the way in which this most irrational of all BMW models drives. Nimble like a go-kart, instantaneous throttle response, goes round bends as if it’s on rails – it fits the driver like a glove, making it so much fun to drive! The sensation generated by the raw motoring experience is further heightened by the fact that you are virtually sitting out in the open air – it’s like a motorcycle on four wheels.” The verdict: “It’s one of the most fun cars we’ve ever driven, and that’s the absolute truth.” And there was certainly no doubting the exceptional nature of the BMW roadster either. As one news magazine summed up: “It is the most extraordinary BMW since the days of the one-door Isetta with its entrance between the front wheels.”
The price for the Z1 had by now climbed to DM 83,000, but in no way did that deter the buyers. Some 4,000 orders had already been placed, meaning the Z1 was already sold out until the end of 1990. And when the first production models rolled off the assembly line in early 1989, sales contracts that were ready for delivery were already being advertised in newspapers for a premium of DM 20,000.
After a run of 8,000 BMW Z1 models, production came to an end in June 1991. It had breathed life back into a segment in the BMW portfolio which continues to enjoy immense popularity today: two-seater sports cars with a Z as their distinguishing letter. The small number that were made, the unique overall design concept and, not least, the tremendous driving pleasure it generated have today earned the Z1 a place amongst the modern classics of BMW automotive history. 25 years on, these cars still have a futuristic look about them and are still in active service: at least one Z1 has a certified mileage of over 330,000 kilometres (205,000 miles). The future never grows old.