(MotorSport,
August 1977. UK.)
The BMW company of Munich may bring out an almost bewildering number of new models – you will soon be hearing about the great top-range Series-7 cars – but it retains the basic formula which has elevated BMW to a supreme rank among the World’s best. BMW continue to place their faith in an in-line six-cylinder single-overhead-camshaft engine, in varying capacity sizes, with carburettors or fuel-injection to provide the power they require. They use suspension which permits of very “forgiving” fast cornering, allied to supremely accurate steering. The outward appearance of every model reflects good taste without ostentation, and all the models in the wide range are unmistakably modern BMWs.
There can be few less-ostentatious fast motorcars than the BMW 633 CSi coupe. It tends to attract appreciative looks only from the knowledgeable. The ordinary observer hardly associating this compact, handsome, 8ft. 7 in.-wheelbase car with a top speed of over 130 mph in manual-transmission guise, and acceleration in the order of 0-60mph in some eight seconds and a standing-start ¼-mile devoured in less than 15 seconds. Yet such are the capabilities of this top model BMW (until the 7-series), which uses an 89 x 86 mm (3,210 cc) version of the ohc 6-cylinder power unit, with Bosch L-Jetronic petrol-injection, to produce no less than 200 (DIN) bhp at a modest 5,500 rpm. Suspension is by coil springs, and is all-independent, using MacPherson struts at the front, semi-trailing links at the back. To arrest this very quick but unobtrusive car BMW have gone to ventilated disc brakes front and back (only front discs are ventilated – Bram Visser), of 11 in. and 10.9 in. diameter respectively, vacuum servo-assisted, the system being ATE.
The body is a two-door, full four-seater coupe, with a luggage-boot which is truly capacious. As expected of a BMW, the interior is quietly appointed, again without a trace of ostentation. Comfort, rather, is the key-note. The present price here of this 633 CSi, which can be regarded as a more civilised edition of the famous lightweight 3.0 CSL coupe, is £14,799 – I may as well get this over with, before describing the car’s near-perfection! This price applies to both the 4-speed manual and the automatic-transmission version of the 633. For test I had the former, another example of which we have “on the strength”, successor to a 3.0 CSi.
I was frustrated at the last moment of testing this fast BMW 633 abroad. But it gave me some very enjoyable motoring in restricted, speed-conscious Britain. I was immediately enamoured by the cloth-cum-leather-upholstered seats, hard in the comfortable BMW fashion, and adjustable for the driver for height and tilt-angle as well as reach and back-rest angle. The windows are electrically controlled, the action somewhat sluggish. If it is necessary to move a window-glass when the ignition-key is not available, this is done by opening a door – an excellent arrangement. The three main instruments live in a binnacle before the driver – big central speedometer, smaller tachometer, and heat/fuel meter. The clock on the left, angled towards the driver’s sight-line – I thought the instruments slightly less easy to read than those on the Editorial 520i BMW. Neat warning-light windows are set above the main instruments and to the right of the facia you have an ingenious warning panel, on which lights come on if the services they cover are in order, at the pressing of a single button. Thus this panel tells of correct oil-level, brake-fluid level, coolant content, screen-washer content, and the brake pads put on, it also tells if oil-pressure and the stop-lamp and rear-lamp bulbs are functioning properly.
The steering wheel has four horn pushes, there are the usual BMW heater and ventilation controls, in the form of rotatable selectors, illuminated at night, and the electric window switches are down on the central console. All four seats have head-restraints and luxury touches include the provision of a re-chargeable torch in the cubby-hole, a first-aid kit under a lift-up panel on the rear-window shelf, and the expected BMW tool-kit in its compartment on the underside of the boot-lid. The o/s driving mirror adjusts electrically. But the real reason why I describe this 633 CSi BMW as coming near to perfection is the combination it gives of very great performance, comfort, docility, and fine engineering. I liked its modest outward demeanour – apart from the styled “multi-spoke” road wheels; they were shod with Michelin XWX tyres, great 195/70 VR14 radials. I liked its logically arranged, straightforward controls. I especially commend the excellence of BMW power-steering, which imperceptibly but most usefully raises its ratio as less lock is used. It is geared 3½ turns, lock-to-lock, and is among the finest of its kind, by ZF, with a 14.7 in.-diameter steering wheel.
In spite of the very impressive speed and acceleration, this BMW is the personification of docility, the engine pulling smoothly from very low rpm. Yet it can be safely extended beyond the peak rev. limit when maximum performance is called for, when it is as smooth as a turbine and about as quiet. It starts and idles impeccably, hot or cold. And it gave me an overall fuel consumption of 21.3mpg. (The tank holds just less than 15½ gallons.) And BMWs never seem to use any oil.
Here I want to digress to remark that BMW steering not only functions so well but is as long-wearing. The manual steering on the aforesaid 520i shows no free-play at a mileage of over 54,000, in spite of the heavy loads imposed on it when parking the car – so heavy that, after driving other cars, I have started to move off in the BMW and have been convinced, erroneously, that a front tyre has gone flat. The accuracy, too, is just as good as when this L-registered vehicle was new. It is this combination of steering accuracy and forgiving cornering that makes any BMW so pleasant to drive quickly, whether a 633 or a 320. These qualities are pronounced in the 633, although the suspension, attempting to give good road-clinging without discomfort, has a curious floating feel over some surfaces, while being quite harsh over unmade roads. Maybe this is why Tom Walkinshaw, 530i driver in the Saloon Car Championship races, has specified modified suspension on the recently-announced “limited-edition” 633 CSi (price £21,300), as well as engine and other modifications. I think I might prefer this.
The brakes, of course, function very effectively but there is an unusual item to the hand brake, which works on inner drums on the rear discs – the car rolls a few inches after applying the brakes; unimportant, but disconcerting when first experienced. Another small idiosyncrasy was that so good is the door-sealing of the Karmann body that you either have to slam the doors heavily to get them to close, or have to first open a window – as on my 1955 VW Beetle. Cool-air ventilation wasn’t 100%. The car I drove had the Getrag four-speed manual gearbox. If anything, it is even better than those in other BMWs, the gears seeming to feed themselves into mesh at the bidding of the stubby central lever.
The clutch is rather decisive in action. Revised rear suspension and a limited-slip differential aid adhesion when using the 633 hard in the lower gears. In fact, the only real irritation about this excellent near-perfect BMW that I can recall was the graunching of the wiper blades – I have suffered this on the old 520i, inspite of BMW servicing, so I assume it is attributable to the kind of wiper-blades the Germans fit. It would take more than that to mar the pleasure to be derived from using this splendid BMW 633, in which I enjoyed nearly 700 very restful, mostly rapid, miles.