The R.A.C. Tourist Trophy Race
THE ninth Tourist Trophy of the R.A.C. was run this year for the third time…
The Editor tries the BMW 628Csi coupe and the Porsche 924 Turbo
These are two makes of car for which I have enormous respect. I used to be very well acquainted with both but for several reasons BMW and Porsche models have eluded me until recently. So it was with some feeling of enjoyable anticipation that I made re-acquaintance with them.
The BMW was to be sampled first, in the form of the new (the Munich Company is so keen to up-date its range of models that it may not be quite the newest when you read these words) 628Csi coupe. The idea behind this particular model out of the big selection of different BMWs is that not everyone needs a full-scale road-burner that gallops up to 140 m.p.h. at the rate of pick-up best expressed as 0-60 m.p.h. in 7 1/2 seconds, I should think not indeed, but that there are discerning drivers who can appreciate a luxury coupe with a smaller engine than the 635Csi, giving better economy while giving nothing away in comfort and convenience.
So this 628Csi has been introduced, with a fuel-injection six-cylinder engine that at 2,788 c.c. gives away 0.7-of-a-litre to the equivalent 635 model, but will still get up to some 130 m.p.h. and accelerate from rest to 60 m.p.h in a matter of about nine seconds. That is decently fast enough for many of us, on restricted British roads, and I personally was happy not to have my passage proclaimed by the 635’s front spoiler and rear air-dam.
Incidentally, BMW are rather interesting in the matter of options — I mean options, not extras. For example, that now all-too-rare cosseter, real leather upholstery, is normally fitted on the 628Csi but if you are of the opinion (which I am not) that this is too cold, too slippery, too much of a pants-polisher, they will do your seats in cloth. Similarly, you can have Recaro front seats and competition suspension at no additional cost, and I think I would have liked these. Extras you do have to pay for, that the test-car had, are headlamp wipe/washers, an electric sliding roof, a limited-slip differential, head-restraints for the back seats, and air-conditioning. This totals an additional £2,397 on the car-price of £16,635, so that it comes out almost as expensive as the faster BMW coupe, without these options which I prefer to call extras.
If I had to economise while still being able to afford this kind of BMW I might opt against the headlamps-cleaning (£211) — a duster being so much cheaper but much more trouble — and as I do not rate as a rally-kid boy-racer (alas!) I would go for an unrestrained differential, except that not having driven a 628 so equipped, I don’t know what the difference would be. As I don’t think about having ghastly accidents anyone who elected to sit behind me would have to do without neck-protectors (£67). Air-conditioning? Awkward, because if the test-car was so embellished I didn’t notice and what I thought of as an inconveniently insensitive hot/cold air-supply was to be a main criticism of this car. In the absence of any instruction-book how was one to know how to set this luxurious device? It costs £1,212 anyway . . .But the sun roof (£624) I would want, although there is only a quite small roof opening. If you prefer automatic transmission to a nice 5-speed manual box, the extra cost is £360.
Anyway, coming out of an office conference one winter evening, the resumption of my BMW love-affair awaited me in the car-park. Getting into a strange car in the dark can present minor problems, even to the experienced. So full marks to this well-endowed 628 for not doing so. After a brief call at a daughter’s flat to revive a flagging body with tea and toast I set off in the dark for Wales, 170 familiar miles away, very happily, not knowing that fog was the order of the night. However, following a motor coach, dazzled by its huge rear fog-lamps from Oxford to Evesham, gave time for contemplating the 628’s details.
I used to use BMWs regularly, but that was in the dark ages, centuries ago. Yet it was apparent that these well-engineered and conceived motor cars have not changed much, haven’t lost any of their (to me) former appeal. Nor their little idiosyncrasies. Like the driver’s door needing a decent push to close it fully, the hand-brake not holding on hills unless firmly applied, the cubby-lid containing a dangerously-situated lock waiting to snag unsuspecting wrists, and the headlamps being less good on dipped than on the powerful full-beams (on the 628 these are still twin circular Hella lamps on each side, of 5 1/2″ dia., and 55W halogens). The two big circular heater/ventilation controls and similar fan control on the fascia haven’t altered either (where was that air-conditioning setter?), nor has the subdued interior trim, and those easy-to-read black-backed instruments, which endear BMWs to those who hate flamboyance in a motor car. And thank St. Christopher for a steady-reading fuel gauge. The seats remain hard, the gear-change as good as I remembered it, with five forward speeds on this 628Csi, reverse and fifth both outside and forward in the gate; apart from occasional baulking between 3rd and 2nd, the gear changes go through very nicely, with rather long fore-and-aft lever movements, reverse being delightfully easy to engage.
On un-congested roads the 628 coupe comes into its own. It will cruise fast quite effortlessly, the beautifully-made, in-line, six-cylinder, 86 x 80 mm. single-o.h.-camshaft engine hardly turning over at some 2,600 r.p.m. at the legal cruising speed on normal British roads or at 3,000 r.p.m. on our Motorways. Use the gears and accelerator to some purpose and the response is highly effective, and smoothly administered, although without a Rover’s eight-cylinder suavity. The BMW’s overdrive fifth-gear gives the impression of being a proper cruising ratio, whereas on so many cars it seems too low, suggesting that the speeds at the other end of the gearbox are unnecessarily so. Although you can run this BMW in 5th at 30 m.p.h., it feels uneasy, treated thus, so it is prudent to drop into normal top with an easy, if long-travelled, move of the stubby, gaitered gear-lever. Certainly there will be no quick response unless you do.
The suspension is another reminder of my old BMWs. It allows quite a lot of movement and yaw, not as pleasantly as does that of an Alfa Romeo, perhaps because a BMW feels a heavier car. Yet this does not spell poor road-clinging or call for cautious cornering. The reverse, in fact, aided on the test-car by Michelin XWX 195/70 VR14 tyres, on the light-alloy wheels. The power-steering, geared 3 1/2 turns, lock-to-lock, is as pleasing as ever. The 15″ dia. steering wheel has four horn-pushes in its spokes, which are not always there when wanted. While any BMW gets very high marks in my book for controls and layout thereof, both fuel-filler position (sensible cap on a vertical neck, under an unlockable flap) and bonnet-release have not been “corrected” for a r.h.d. car, which at a £16,000 purchase-price one might have expected. The turn-indicators are worked by the left hand of the two control stalks. Normally I can do without computerisation but confess that the 628’s neat r.h. panel of single-button-operated warning-lights for checking that all was well, even to rear lights working and screen-washer bottle charged, was welcome. Even so, it is possible to leave the side lamps on inadvertently.
As I have said, the suspension is on the lively side, in spite of the strut-damped all-round independence, but the all-disc brakes function with enormous power, after a momentary sense of nothing happening, another BMW remembered characteristic. The system is servo dual twin-circuit, mine 10.7″ discs.
The 628Csi engine delivers 184 (DIN) b.h.p. at 5,800 r.p.m. and in the absence of an instruction book and no warning marks on the tachometer, I assumed could be run up to the indicated 7,000 r.p.m., which was, of course, never needed. The torque figure is 177.2 ft./lb. at 4,200 r.p.m.
The steel coupe body has two wide doors with good “keeps”, access to the shaped back seats being easy. The boot is enormous (14.6 cu. ft.). Quiet central door-locking is a boon, the boot being included. Although this is a two-door car it has what was once dubbed a 4-light body, meaning one with four side-windows. On the 628 all these are electrically operated, from four neat controls on the gear-lever surround. For the nervous, let me say that this body possesses a hidden roll-over bar in the roof centre. A dangerous item to those who cannot think of motoring without visualising bloody accidents is the hard “peak” of the 628’s angled fascia, although I expect Mr. Paul Layzell of BMWs will tell me it is collapsible.
I do not propose to itemise the impressive 628Csi further, because it is so similar to the 635Csi coupe that was the subject of a long report in Motor Sport for April,1979 (photostat copies available). Except to say that the expensive air-conditioning was a disappointment, as I never found out how to drive it correctly, so was mostly either too warm, or chilled. De-frosting, however, worked well, but there is no proper indication of upwards or downwards airflow. The Bosch L-jetronic fuel injection ensured prompt cold-starts. There was all the feeling of quality one associates with BMWs and those “hidden” assets, such as the very full set of tools neatly cased under the boot-lid, which I recall from my 520i days, a digital clock on the fascia, difficult to read in daylight, and a rechargeable inspection torch in the cubbyhole. Stowages consist of a well in the fascia-top moulding, rigid door pockets and a big, lockable cubby below the fascia, but the air-conditioning plant fills the console well. The test-car had a Blaupunkt radio and a Hamburg CR Stereo, with automatically-retracting aerial. Another item that hasn’t changed on this particular BMW is the interior door-handles under the arm-rests, so easy to work that a nervous passenger might fall out! The slightly “squidgy” feel under heavy braking is a legacy of the supple suspension characteristics. Also, there is still too much wind noise at high speeds.
As for fuel consumption, this 130 m.p.h. BMW’s official energy-statistics are 16 – 41 1/2 – 30.7 m.p.g. and the Concessionaires claim over 30 m.p.g. at Motorway cruising speeds. I did a lot of that and, in fact, the overall fuel-thirst came out at 25.6 m.p.g. As the tank holds 18 1/2 gallons the range is impressive. Checked after 800 miles, no oil had been used. The £30-a-year 24-hour BMW rescue scheme seems a good bargain and I must say the 628 coupe proved adept at extracting itself from considerable snow.
After a long spell with BMWs I was weaned away from them by the offer of a V8 Rover 3500. It is more important to Drive British now; but I can see from the 628Csi what I have been missing.
* * *
I had not driven a Porsche for such a long time that when Mike Cotton laid on the 924 Turbo for test I couldn’t at first remember whether it was front, mid, or rear-engined! In fact, of course, it is what some Porsche fanatics would refuse to recognise, inasmuch as a Porsche to them has to have the engine in the back and be air-cooled. Whereas the 924 uses a front-mounted power unit, which is water-cooled. However, this has not prevented it from being the best-selling Porsche model throughout the World, Britain being the second largest export market for this German manufacturer, after America. My trial of the 924 Turbo was appropriately timed, inasmuch as it took place at about the day when, after a five year production run, the 100,000th 924 left the Stuttgart factory.
Anticipating being let loose in one of these celebrated sports cars — I use the term sports car advisedly, for Porsche describe themselves as the only German manufacturer to make just that one type of car — I speculated a bit on the nature of this famous company.
We are used to hearing that Rolls-Royce of Great Britain makes the World’s best cars, you know, or you should if you have read Motor Sport for any length of time, that Mercedes-Benz produce those with the best engineering and most impeccable road manners. But less has been said here latterly of the perfection looked for by the engineers at Porsche, under Helmuth Bott, Director in Charge of Research and Development, when making and marketing their individualistic sports cars. In all, more than 1,100 scientists, engineers, technicians and master-craftsmen work at the Porsche Development Centre at Weissach on tasks connected with Porsche products, research for other companies, and motor-engineering projects partially financed by the German Government. Such research is concentrated very much these days on obtaining lower fuel consumption, but many other factors, such as noise suppression, lightweight construction, improved handling, aerodynamic improvements, rust suppression, safety-factors and so on, are looked at very carefully by Porsche. The exhaust-turbo adaptation to the 924 engine was the responsibility of Dipl.-Ing. Heinz Dorsch, Head of Engine Testing, who has been on the staff since 1966, and of Ing. Julius Weber, in charge of engine performance testing, who has been with the company a year longer than his colleague. Similarly Dr. lng. Dusan Gruden has worked there since 1973, a member of the Propulsion Systems Research Directorate, concerned especially with the TOP combustion-chamber. Hermann Schreiner heads the Experimental Electrical Equipment Research Department. Dipl.-Ing. Reimer Pilgrim looks after vibration technology and acoustics research, Robert Mueller leads the transmission-design department and Dipl.-Ing. Manfred Bantle, who was responsible for the 908/03 racing Porsches from 1968 onwards, heads running-gear research — did you realise that a different specially-developed gearbox is used for every Porsche model? Such transmission is designed under Dipl.-Ing. Wolfhelm Gorissen, while Dipl.-Ing. Hermann Burst looks after bodyshell research.
This splitting-up of responsibilty for various parts of the car is typical of German thoroughness. It is interesting to find that one aspect of the 924 is its rear transaxle, more often called a De Dion axle, although strictly Bollee/Trepardoux might be more accurate. I was always rather pleased that the Rover 2000TC I used to drive had this form of transmission, and disappointed when the Solihull make changed over to a normal rear axle, although admittedly Spen King has achieved excellent handling with this less-expensive layout. The De Dion rear end was used, on a De Dion Bouton, believe it or not, from 1900 in order to obviate a heavy axle assembly pounding the primitive tyres then in use. Later it was used to improve wheel adhesion by thus reducing unsprung weight, to locate the back wheels vertically, and to counter the effect of torque that resulted under acceleration in one rear wheel lifting from the road and tending to spin.
I suppose it can be said that with modern tyres and efficient dampers there is now much less concern over the unsprung weight of a normal back axle and what it can do, and that the limited-slip differential to a large extent answers the wheelspin problem with such a rear axle. So why do Porsche use this form of final-drive, on the 924? They say that a transaxle distributes weight better over the two ends of a car, engine at one end, gearbox at the other, and that it even enhances the car’s safety-factor because impact shocks, applied to either end of the vehicle, are transmitted along the length of the structure, by-passing the central, passenger-shell. I believe a lighter propshaft is also possible, because gearbox torque-effects are not transmitted thereby, which helps reduce overall weight. Be all this as it may, it is nice to know that a form of final-drive associated with a very few, and those exotic, motor cars features in this front-engined Porsche, a legacy from the VW-Porsche design.
Changing the subject somewhat, how does the Porsche 924 Turbo figure on the road? It appeals in so many ways. It is beautifully constructed and turned out. It has practical instrumentation and controls. It responds very well indeed to a driver’s responses, with very crisp, irnpressive acceleration, when the inlined 4-cylinder 86 1/2 x 84 1/2 mm. (1,984c.c.) 170 (DIN) b.h.p. single-overhead-camshaft engine comes “on song”. It is of an efficient rather than an attractive shape, with its low nose, concealed headlamps, and rear spoiler, the bonnet-top broken only by the r.h. air intake. And before criticism is levelled at the very restricted size of the rear compartment of the two-door coupe body, note that Porsche themselves say the back seats are intended for “two children quite comfortably or even adults for short journeys”. Folding the curved rear seats enlarges the luggage space. There is a fine air of restrained good taste about the 924 as a whole, yet it possesses such enjoyable performance and road manners as to make one go out just for the sheer pleasure of driving it, as another writer, many, many years ago, remarked of the then-new 12/50 Alvis.
Porsche finish is renowned for its quality and inside the 924 there is restrained, straightforward efficiency. VDO speedometer, tachometer, and the combined fuel and heat gauge (which also incorporates the warning lights) are before the driver, and the smaller dials, for oil-pressure (reading in bars) battery condition, and time (there is also a digital-clock in the radio stereo panel) are centrally placed, above the triple heater/ventilated horizontal control-levers. The fuel-filler (the cap locks) is on the wrong side for right-hand-drive and the turn-indicators are operated by the left-hand of the two control stalks, the bonnet-release is on the passenger’s side. The hand-brake is on the right but is set so well clear of the driver’s seat cushion as to be perfectly acceptable. The low driving seat is comfortable and gives good support.
The gear-change is unusual in that for the five-speed gearbox bottom gear is far left, below reverse, with the other four ratio locations in an “H”. This constitutes no particular problem, once remembered. If a Porsche driver inadvertently selects reverse, for which there is no safety arrangement apart from some spring loading of the lever away from it, the light clutch engages so progressively that the error should be quickly felt and corrected. Nor is there any excuse for nicking reverse when making a quick change from 1st to 2nd, although the faint memory of doing this on old Ford Anglias and Prefects floated into my mind . . . The stubby lever, leather-gaitered, is a delight to use most of the time, and it is but logical to put the little-needed 1st and reverse gears on the far left. The movements across the gate are close, with the lever spring-loaded to centre, and I confess to not liking this, although the changes go through nicely, except for stiffness if bottom is needed from 2nd gear. It is of course unusual to select 5th gear with a “towards-you” movement but this gear is intended for mainly high-speed cruising. In fact, like most modern cars, the 924 will accept it from quite modest speeds, and although I was told that the 924 Turbo likes to run at above 3,000 r.p.m., it showed no objection to 2,000 r.p.m. or even less. Full acceleration begins at about the former crankshaft speed and the ignition cuts-out when 6,500 r.p.m are reached. The engine gives 181 lb./ft. torque at 3.500 r.p.m., the KKK turbocharger boosts to 10 lb./sq. in. and at 70 m.p.h. in 5th the r.p.m. are 2,870.
The Porsche 924 Turbo’s acceleration is truly exhilerating. With an eager engine note the car picks up speed cleanly, in a very reassuring fashion. It can, for example, do 0-60m.p.h. in just seven seconds, and it gets from rest to 100m.p.h. in just less than 18 seconds. (s.s. 1/4-mile in 15 1/2 sec.). Even more satisfactory is the pick up from intermediate speeds. For instance, from 30m.p.h. you can go to 50m.p.h. in 8.8 sec. without dropping out of normal top gear, and likewise increase speed from 40 to 60 m.p.h. in 6.8 sec., or from 50 to a motorway 70 m.p.h., in only 5 1/2 sec. in the same ratio.
Using the gears, 70 m.p.h. comes up from standstill in only nine seconds. This kind of acceleration from a 2-litre car is highly enjoyable, especially allied to outstanding fuel economy. Top speed is of academic interest but can be set at around 140 m.p.h.
As for Turbo-lag, it is virtually non-existent. There is negative pick-up below about 1,000 r.p.m. but above that no lag is noticeable, as it was on the Audi Turbo, with the Porsche it is more a matter of keeping the revs. up, as expected with any small-engined sports car. In conditions of zero-temperature the engine commenced almost immediately. It uses Bosch K-jetronic fuel-injection.
The small steering wheel has a leather-laced rim and spokes. The action is manual but you could have fooled me, so light is the steering even when parking (3 5/8 turns, lock-to-lock). Low-gearing is required to achieve this but only on tight corners is this apparent. The rack-and-pinion mechanism (do they still lap it on, as was done when I last visited Zuffenhausen?) is precise and almost free from kick-back. The cornering characteristic of this front-engined Porsche is understeer, and the road-holding is of a high standard. The suspension by MacPherson struts and lower wishbones at the front, with torsion-bars and semi-trailing arms for the transaxle rear suspension, and anti-roll-bars at both ends of the car, is firm and transmits some sharp thumps at the back-end at times, with audible bump-thump. This, and the Turbo hum, is entirely permissible in a sports car. Porsche had equipped the test car with XDX tyres, of 185 70 VR15, and the light-alloy wheels have spoking to simulate wire wheels
The carpeted boot is high set, due to the transaxle, but roomy and a spring-loaded blind conceals luggage. Beneath the boot floor there is a Vredstein Space Master inflatable get-you-home emergency tyre, with 12-volt inflator, and because the Law is an Ass this is illegal in Britain (a Dunlop Denovo would be OK). There is rear wipe/wash and full-width seat window demisting. Most of the expected luxury equipment is fitted, in fact.
This Porsche 924 Turbo is great fun apart from an awkward gear change. The all-round ventilated disc brakes, of dual circuit servo type, are well suit to the car and fully in keeping with its considerable performance. I enjoyed myself with it, and whether or not die-hard Porsche-people insist on air-fanned boot-located power, in my book the 924 Turbo justifies the term “thoroughbred”. It comes with a seven-year anti-rust policy, the body being carefully protected, requires servicing only at 12,000-mile intervals (oil change at 6,000) and all the detail work is very good, starting with the neat external door-handles. Electric tinted windows, electric door-mirror, and a Panasonic stereoradio with auto-aerial are part of the “Lux” equipment. I had some difficulty getting fuel-consumption figures in the snow and ice conditions prevailing at the time of the test, but they came out at 23.1 m.p.g. and no oil was needed after 600 miles (the dip-stick is fully accessible). The front air-dam acted as a snowplough but took no harm; this might ground the car in Germany, however, where they have more severe snowstorms than in Britain. The heavy bonnet has to be propped open: the machinery it then discloses is very impressive! The fuel tank takes 18 gallons, so many owners will be able to go for some 400 miles without refuelling.
I hope I have conveyed my enthusiasm for this compact 924 Turbo, the price of which is £13,998. – W.B.
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