Mercedes 4 1/2 litre 'rallyewagen'
I am standing on a low grass bank, surrounded by a Surrey replica of Scottish rally terrain. The gods have even laid on similar weather to the June Scottish Rally. The proverbial crisp sunny day beams down on the mixture of sand and stone, presently peacefully sleeping on the hidden slopes of the approach to the road on which I stand. Now there is a brief shriek of hard-pressed rubber on tarmac; then the clatter of stones being displaced by what sounds like a hot rod vacuum cleaner, but it's coming this way very quickly. A long snout romps into view, and then a large black car wriggles into sight behind. As it gets closer the row of spotlights reflect a very special symbol: the three-pointed star.
The black and gold Mercedes 450SLC makes a moving sight as it shoots into the corner beneath my feet. Inside the cockpit an experienced rally pilot selects the first hold ratio on the Daimler-Benz automatic, and begins a strange ballet with the power-steering and the throttle as his chief methods of expression. The big black coupe slides out towards trees on the outer edge of the bend, before the driver suddenly cranks the wheel back to face the lefthander. The front wheel paws at the edge of a small ditch and stones spurt frantically away from the large Goodyear Ultragrip tyres. The driver harnesses all advertised 225 horsepower from Unterturkheim's s.o.h.c. V8 into the task of straightening out this now sliding 33.4 cwt. monster. Full throttle is allocated accurately by the ZF limited slip differential, and the £13,950 Mercedes flails swiftly between the shrubbery and surrounding trees, slithering out of view with astonishing agility.
First one must state the obvious. "No, Mercedes are not back in motorsport". Despite the persistent rumours that link Mercedes with a European Touring Car Championship effort with AMG, their dealer in Stuttgart, the fact remains that the people who presently hold the balance of power within the Unterturkheim factory complex are firmly set against any competition effort. If the factory are going to compete, the reasoning goes, they compete as an all-out effort that fully involves company engineers. Mercedes would never countenance a Broadspeed-Leyland Cars Jaguar operation, preferring to have complete control themselves.
What has happened is that one of those proverbial young whizz kids, in this case Jonathan Ashman, the assistant to the present MD of Mercedes in Britain, is fully infused with the competition bug. Jonathan does not appear to be a man of great sentiment. He looks at Mercedes and competition without the benefit of memories encompassing the silver works machinery that has shaken and dominated the competition world whenever the company has seriously contested either a championship or individual events. By definition the British branch of Mercedes is more of a sales company than a complete factory operation, so there are not so many of Ashman's persuasion as there are in Germany. Somebody must be listening somewhere, or the project we are discussing here could never have reached fruition.
For Ashman the story begins in 1975. Having gone straight from College to Mercedes with a business and business finance background, Ashman managed to extract a secondhand 280E from the Great West Road operation, preparing this demonstrator car for the Tour of Britain. By a coincidence he took the most junior journalist at Standard House along as his co-driver, so we heard a lot about the project all along. Complete with power steering and automatic transmission, this 280E managed a third in class, finishing just inside the top twenty overall.
It had been an uneventful outing so far as the car was concerned, and the feeling inside the company was obviously that the car had acquitted itself honourably against purpose-built rivals.
The 450SLC you see on these pages was also prepared for the Tour of Britain (1976), and was another demonstrator car. This time the decision was taken to mount a fairly professional effort. The automatic, powersteer, electric-window, air-conditioned coupe was to be driven by semi-professional Tony Fowkes, who lists his main occupations as split between driving and a garage in London NW10. Fowkes had been cheerfully pounding around Britain's regular rally venues in a variety of Escorts. Tony had proved his ability with a third overall on the 1975 RAC Rally, besides featuring regularly in the top half dozen on RAC Championship events. Fowkes is a deceptively gentle chap to talk to, but when he gets into a car it is arms, elbows and gritted teeth the whole way.
When I first went for a ride in the car, it really was awfully standard, and there's been little difference in basic thinking today. Tony says of his introduction to Mercedes, "I had always driven Fords, so this was obviously going to be something different! I thought of the cars as old taxi-cabs, or in the Jaguar limousine standard, definitely not rally material. Initially I tried the 350 SLC at Silverstone, and I came away convinced that the steering and handling would do the job, but the car simply wasn't fast enough . . . we had to have the 450 V8 for acceleration. Now I am convinced there is still more to come from me, than the car, you can go so deep into corners it really is different to drive."
For the tour the car went through basically the same preparation as the specification to which it conforms today, that is FIA Group One. Now the Mercedes 450 SLC in Group One form is a very "straight" device, by which I mean it conforms to the letter of what the manufacturers have actually made for 5,000 production vehicles. Because Ashman was basically taking a car out of demonstration use it had to be a pretty simple specification too, for with the original car the idea was that it could be sold fairly simply, without a lot of re-conversion work.
The car seems to be the baby of Eddy Chalk of the Service Division at Mercedes in Britain, but it has also spent preparation time at the training school, and at the Fowkes Premises, The result is some basic preparation that has proved astonishingly effective.
Inside the Mercedes is a massive roll cage system from Safety Devices in Cambridge. The beautiful brown fabric seats provide a splendid vantage point for both navigator and drivers The steering wheel looks like the normal production item, though it is actually removed from elsewhere in the Mercedes range. No fireproofing of bulkheads is required, the Mercedes personnel just grinning at this exhibition of their products' inbuilt safety precautions. Comprehensive restraint is provided by the comfortable Luke harness on either of the front seats.
The suspension is considerably altered in feel, but not in fact. Heavy duty Mercedes specification coil springs and Bilstcin gas dampers are installed. This raises the car by 1 1/2 in., the all-adjustable production suspension being adjusted to give manufacturer's camber and other readings, despite the altered ride height. The four wheel ventilated discs benefit from Ferodo competition pads and a high temperature brake fluid. The brakes are terrific, but in this weighty automatic, stressed to the limit over difficult terrain, it would be unrealistic to say they offered any feeling of wanting to do any more work.
Originally the air conditioning, like thc agile (just over three turns lock-to-lock) power-steering, was retained. However, following a tenth overall on the hotly contested Tour of Britain, the weighty air conditioning pump itself was removed, though the rest of the unit is in situ.
Weight is actually the heart of the Mercedes competition career. The factory can build one of those coupes down to little more than 24 1/2 cwt., in fact ballasting the car in Gp. 2 prototype guise to achieve this figure, but for this standard looking project no systematic diet has been followed. Most of the time this means the 150 horsepower realised at the rear wheels—this after 25,000 miles is within 2-3 b.h.p. of the maker's figure—about 3,700 plus lb., which is not a very competitive ratio. Maximum torque should amount to 279 lb. ft. at the flywheel.
As Tony Fowkes grins, "there are only two ways to go: take weight off, or blueprint the engine for more power, or both. But we're in a situation where the factory cannot be associated with the project, so everything has to be paid by Johnsons Wax, and they are not in the business of paying development costs for rally cars, particularly ones that are already getting a lot of publicity without spending any more money! However, it did all work out for us on the Eppynt Rally at Christmas time, for the combination of the automatic and the car's weight let us really feel in our element. I could run in the unmarked snow, and we could find more grip than the rally Escorts." In fact this was a sensational performance. Fowkes finishing fifth overall and setting fastest times twice during the afternoon of this ice-bound event. Present plans are to contest the remaining rounds of the British Castrol-Autosport series.
Tyres obviously have to be quite special for the demands of this bulky coupe. Goodyear have supplied superb 7.0/21.5/14 G44 covers for smooth tarmac, but they are such a rarity we weren't able to do more than record our fifth-wheel times on them. For the loose, taller profile 185 SR M&S radials of appropriate chunkiness are employed. In fact the pressures within these tyres, especially on tarmac, were critical and Mr. Chalk proved the point by leaving just a 2 lb. differential 'twixt front and back for much improved handling. Whether on the rough or smooth, there's plenty of good old-fashioned tail-out motoring to be enjoyed with this torquey engine and "narrow" tyres on the 17 in. rims. Initially the car does understeer, but there's more than enough stick available to cane the rear end out of line before you reach the 5,750/5,850 r.p.m. engine cut-out point. From 2,500 r.p.m. the car rumbles forward very readily, adopting a very potent thrust forward from 3,000 r.p.m. onward. The first hold on the automatic is very useful, but the second hold can be quite hairy as the unit will kick down to first under full power and then change up to second. Sometimes this occurs at the most inopportune moments, creating a kind of terminal understeer that is truly unnerving when you have just been warned, "I hope you carry plenty of insurance; this car's unique ! "
The outstanding quality on the loose is the big coupe's agility. The power-steering and super brakes all help contain the V8's apparently boundless energy. Thus the car can be braked at right angles to the intended course, and then twitched back into line in text book style. Sometimes you get the feeling that all this weight is going its own way, but there's a lot of lock quickly available with this power-steering. Tony did spin the car twice for our demonstration, but the speed at which this happened is really highly creditable, and even as a passenger you can feel that the big car is unhappy long before it finally lets go. When I was driving sudden understeer as the automatic went from first to second was a far more pressing problem. Another outstanding characteristic is the traction on the loose. The combination of weight, automatic transmission and a limited slip differential allow almost rear engine standards of traction. The Mercedes just seems to squat down on its haunches a little and fly down the straights. In fact when the car reaches 60 m.p.h. on the loose it really seems to get into its stride and our short straight was just swallowed up with contempt.
The car's tarmac performance can be adjudged from the attached figures returned via fifth wheel and stopwatch. More relevant to most may be the observation that these bear close resemblance to a works specification Escort in Group One trim (that is considerably, and effectively, modified to beat allcomers on most British events) so Ashman and Co. really have very little work left in order to turn the car into a guaranteed class winner under most conditions. However, the signs are that they will start again with a new car, so this 450 SLC could go down in history as a unique Mercedes "Rallyewagen". Since the new Mercedes choice is smaller and has better power-to-weight ratio, we could see Mr. Fowkes edging his way quite a lot further up the overall results sheet, as well as winning classes en route.—J.W.
Mercedes 450 SLC (rally modified):
0-30 m.p.h. 3.38 sec,
0-50 m.p.h. 6.23 sec.
0-60 m.p.h. 8.30 sec.
0-70 m.p.h. 10.95 sec.
0-90 m. p.h 17.60 sec.
0-100 m.p.h. 22.52 sec.
Gear holds at 5,750 r.p.m.
1st; 46 m.p.h.
2nd; 72 m.p.h.
3rd; 120 m.p.h. at 5,500 r.p.m.