Out in Front: The Front-Wheel-Drive Oldsmobile Toronado

[NINETY EIGHT REGENCY]

Out in Front: The Front-Wheel-Drive Oldsmobile Toronado

Written by Aaron Severson

Monday, 16 June 2008 13:53

Despite the geriatric image it acquired in its declining years, GM's Oldsmobile division once had a reputation for engineering innovation. It was Oldsmobile that introduced the world's first fully automatic transmission, the first high-compression OHV V8 engine, the first turbocharged production car, and, of course, the first front-wheel-drive car built in America since 1937: the Toronado.

FORWARD THINKING

Until the 1970s, the large majority of production cars around the world adhered to what is sometimes called "Le Systeme Panhard": a front-mounted engine driving the rear wheels, usually via a long propeller shaft that connects the transmission to a differential between the drive wheels. This layout has its drawbacks, but it is simple, durable, and, most critically, cheap.

Although it did not become commonplace until the late sixties, the idea of a front-mounted engine driving the front wheels -- front-wheel drive -- goes back decades. It was essayed on a small scale before World War One, and in the 1920s, Harry Miller even ran front-drive race cars at the Indianapolis 500. Although some European manufacturers, notably Citroën, used front-wheel drive with some success starting in the 1930s, it remained quite rare even in Europe until well after the war. In America, the only serious efforts at production FWD cars were the Cord L-29, the Ruxton, and the Cord 810/812. None was commercially successful, and all perished before America's entrance into World War Two.

Front-engine/front-wheel-drive (FF) layouts offer several advantages:

Space and weight efficiency. In a front-engine/rear-drive (FR) or mid-engine (MR) car, the bulk of the transmission, prop shaft, differential, and driveshafts reduce the amount of interior space available for passengers and cargo. Installing the complete powertrain at one end of the vehicle (as in an FF or rear-engine/rear-drive (RR) layout) leaves more room for occupants and luggage. It also eliminates the weight of the propeller shaft.

Wet-weather traction. The engine is usually the largest single mass in any car; placing it over the driving wheels tends to give better traction in snow or on wet pavement. By contrast, an FR car often has less than 45% of its static weight over the drive axle, making it more prone to spinning its wheels on slippery surfaces.

Straight-line stability. In an FF car, the longitudinal center of gravity is usually well forward of the longitudinal center of aerodynamic pressure, which provides greater stability at high speeds and better resistance to crosswinds. (By contrast, MR and RR designs tend to be more susceptible to crosswinds, because their center of gravity is close to the center of pressure.)

Ease of assembly. Front-wheel drive generally allows the drivetrain to be installed in the car as a single unit, which makes it easier (and thus cheaper) to put together on the assembly line.

There are also a number of disadvantages, including torque steer (the tendency of the engine's torque to steer the front wheels) and a propensity for understeer. Nevertheless, the packaging and weight advantages are compelling, which is why most small cars designed since the late 1960s have used front-wheel drive.

THE UPP CONCEPT

Despite its advantages, American automakers were very slow to adopt front-wheel drive, primarily because of the cost. All else being equal, front-wheel drive is not necessarily any more expensive than rear-wheel drive, and in some cases, may even be cheaper. However, the American industry had invested heavily in rear-drive hardware, and designing and building FWD cars represented a hefty investment. Several automakers, including Kaiser, had flirted with the idea, but inevitably, the accountants ruled against it.

Both Ford and GM experimented with front-wheel drive in the fifties, although with no immediate intention of offering it in production cars. Nevertheless, some engineers, like Ford's Fred Hooven, strongly advocated front-wheel drive for its greater packaging and weight efficiency.

Hooven called rear-wheel drive "antiquated," and contended that if Ford's cars were already front-wheel drive and someone proposed switching them to rear drive, the drawbacks of the idea would render it laughable. Despite his impolitic candor, Hooven understood the development cost issues, so he devised a unique "power pack" concept, combining engine, transmission, and differential into a single, compact package, using many preexisting components. Hooven proposed this system for the 1961 Ford Thunderbird, but the inherent conservatism of Ford management -- and perhaps their disdain for the colorfully eccentric Hooven himself -- doomed the idea early on. Although Ford adopted front-wheel drive for the German Ford Taunus 12M in 1962, a planned FWD version for North America, code-named Cardinal, died stillborn.

At GM, the corporate Power Development and Transmission Development teams devised a very similar concept in 1955, which the engineers dubbed the Unitized Power Package, or UPP. Like many GM corporate engineering efforts, this was not intended for production, and development delays meant that GM didn't even use it for its original intended purpose, the LaSalle II show car. The UPP concept ended up on the shelf.

BELTZ AND BRACES

In early 1958, a bright young engineer named John Beltz, then Oldsmobile's assistant chief engineer, became very enthusiastic about the possibility of using front-wheel drive for a compact family car. At that time, Oldsmobile was already working on a compact sedan that eventually emerged in 1961 as the Olds F-85/Cutlass, but the F-85 was a FR car, with a small V8 engine and a live rear axle. Beltz convinced Oldsmobile advanced engineering chief Andy Watt to let him build an experiment front-drive F-85, using the Unitized Power Package concept. Watt called the results "highly encouraging," but Oldsmobile's conservative general manager, Jack Wolfram, thought a FWD F-85 would have to be far too expensive to be viable in the compact car market.

Beltz nevertheless managed to convince his boss, Oldsmobile chief engineer Harold Metzel, that front-wheel drive was worth pursuing. Metzel eventually convinced Wolfram, and the two of them asked the corporation for approval to build a full-size FWD car. GM chairman Frederic Donner was skeptical, and responded that he could not approve such a concept until Oldsmobile demonstrated a fully developed car to the executive committee.

A LOT MORE OF THE STORY AT THE LINK:

http://ateupwithmotor.com/component/content/article/95.html