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    samedi 12 janvier 2013

    Porsche 911 Carrera 4S: Snowed under


    There’s no doubting the fact that, in snowy conditions, a Porsche 911 Carrera 4S is a good choice. But when the conditions get slippery, can you still have as much fun with a 4wd car as you can with the standard Carrera S? We went to the Col de la Croix deep in the Swiss Alps to find out. 



    It’s a simple calculation: the weight of the car (say 1,500kg) is multiplied by the theoretical grip of the road (perfect traction will equal ‘1.0’) and you then get the available braking force, in this case 1,500kg. When it rains, the multiplier reduces to 0.7. In snow it’s 0.2 and in wet snow 0.1. Factor in a downhill slope and the braking forces are negligible. Welcome to the new Porsche 911 Carrera 4S, Bienvenue au Col de la Croix.
    Adding four-wheel drive makes no difference when it comes to braking on ice and snow. But distributing the power of the boxer engine to all four wheels, rather than two, is seen as a benefit and has resulted in two out of three customers in Switzerland choosing a 911 Carrera 4. If you add the all-wheel-drive-only Turbo to the figures, 4wd accounts for 85-80 per cent of Swiss 911 sales.


    So let’s take both 2wd and 4wd cars out and try them on snow. First of all, the standard Carrera S. Starting uphill, the tail soon wags, while in the new 4S traction is far better and the driver can admire the clever electronic and mechanical assistance via a colourful display on the dash. All very reassuring, but whatever happened to the famous ability of skilled drivers to swing a Porsche’s tail out in bends? Since the engineers at Weissach and Zuffenhausen are not averse to a little (safe) fun, with some driver training it’s still possible to drift a 4S ‘the old way’.


    The company offers a driver coaching programme on closed roads in the mountains, so customers can hone their car control in safety. But even without that, be assured that the new 4S has the capability to look after you most of the time – without the need for switching modes or pressing buttons. The system makes millisecond-quick changes in torque vectoring, via Porsche Traction Management (PTM), to ensure that the 400bhp from the 3.8-litre flat-six is distributed to the wheel with the most grip. Pressing ‘Sport’ and ‘Sport +’ means the system can be overridden to a certain extent for some old-style sliding.

    You will notice the 4wd car’s wider rear track – another stability aid.
    Drifting in circles, performing ‘doughnuts’, is a little more difficult now, but by holding the throttle at 4,000rpm with just the right amount of lock on the steering wheel – and having nerves of steel – the Carrera 4S soon starts to disappear in a cloud of powdered snow.


    You then realise that 4wd is not just about safety and security; it’s about fun, too. You cannot really ask for more than that.
    Related Links

    For further details on the Porsche model range, visit www.porsche.com

    A selection of new and classic Porsches can be found in the Classic Driver Marketplace

    Text: Jan Baedeker (ClassicDriver)
    photos: Jan Baedeker / Dirk Michael Deckbar

    THE 564HP STEAM PUNK SPEED FREAK


    There are some cars which have the power to completely captivate all of those around them just by their mere presence. No sound. No fanfare. Car people just know when there’s something special around. Heads turn, a crowd gathers. Jaws hang open. I know of few cars that have this power more than the astonishing Napier-Railton, a car which is 80 years old. I think this is one of the most beautiful, imposing cars ever made. And then you hear the 24-litre aero engine running: grown men weep, children gasp, angels sing. The aero engine at the heart of the Napier-Railton is the sound of a thousand storms. It’s the sound of… victory.
    I defy anyone to witness this car in the flesh and dismiss it as an irrelevant automotive anachronism. So it’s positively medieval in the technology it uses. So it’s not the product of some fashionable tuning house (though actually in period it was…). It’s not a well-known name. It’s old; most likely far older than anyone reading this.
    But just look at the next picture and I think you’ll understand.
    Four wheels off the ground at the Brooklands oval as the car hits the bump on the bridge over the River Wey and already pulling over 130mph, John Cobb hangs on to his two-ton leviathan as he approaches the Railway Straight, where the car will accelerate to almost 170mph.
    Just 17 drivers lapped the 2.8-mile Brooklands oval at more than 130mph, earning one of the circuit’s coveted 130mph badges. Cobb went even further, setting the fastest ever lap of the banked Outer Circuit in the Napier-Railton at an average speed of 143.44mph in 1935. It’s a record that will never be beaten: here we have a car that has outlasted the track it became so famous on.
    The Napier-Railton is everything you could ever want in an automobile, as long as it’s not comfort, a CD player or a bad body kit. It was an endurance racer. A dragster. A Time Attack specialist. A Land Speed Record holder. And it won everything. Built over the winter of 1932 the Napier-Railton quickly became recognised as the ultimate Brooklands racing car, the most historic and revered racer in the circuit’s 32 year history and the perfect encapsulation of the spirit of that era.
    The car is intimidatingly large at almost five metres long and has a wheelbase over three metres, but has a streamlined body, raked and curvaceous, that belies its age and sets the car apart from the more angular, upright contemporaries. Sheer power and speed look like they’ve melted the Napier-Railton and raked the whole thing backwards, accentuating the impression of speed even when it’s standing still. Like any good modern car in fact. This is the Bugatti Veyron of its day.
    Contrary to the suggestion given by its size and weight, this was a well-developed, advanced racing car. It steered easily and was tractable to drive; braking was good, despite the limitations of the drums. Even people who are lucky enough to drive the Napier-Railton today comment on how docile the car is: almost impossible to stall with its galaxy of torque, and voluptuous in turns.
    The architect of the Napier-Railton was John Rhodes Cobb, Brooklands’ ‘Gentle Giant’, who had lived near Brooklands as a teenager and cycled down there to watch the racing. After making his career as a successful fur-broker he had the funds to pursue his childhood passion, and in 1925 drove a 10-litre FIAT to victory – in his first ever race. He subsequently raced Parry Thomas’ famous 27-litre ‘Babs’ Special, before buying a V12 Delage in 1928. Wins became the norm, but as the years went on the competitors raised the bar – and none more so than ‘Tim’ Birkin.
    Sir Henry ‘Tim’ Birkin had raised the Brooklands lap record to a 137mph average in his Blower Bentley, out of the reach of Cobb’s Delage. With his sights set on that speed and also on taking the World 24 Hour record, Cobb commissioned Reid Railton to design him a new car, with money no object.
    From Railton’s pen flowed the Napier-Railton, and Brooklands-based manufacturing specialists Thomson & Taylor were engaged to build it. T&T had fabricated Malcolm Campbell’s Bluebird Land Speed Record machines, and were also Alfa and Railton maintenance specialists.
    Enormous capacity aero-engined racers had dominated the record books at Brooklands after the First World War, so the the chosen powerplant was a Napier Lion Type E89 Series XIA 12-cylinder ‘broad-arrow’ aero engine. The design dated from 1919, but was chosen for its power and rugged reliability – it was based on a unit used by the Royal Air Force in the ’20s.
    Despite its huge displacement of 24 litres, the aluminium block and cast head are relatively compact and allowed the bare aluminium body to be far lower than the previous generation of aero-engined monsters – almost streamlined in fact.
    The engine was in a W12 configuration, with three banks of four cylinders. The outer banks are installed at 60 degrees to the central bank, which resulted in the elaborate triple exhaust system. Double overhead camshafts connect to each bank, with four valves and two spark plugs per cylinder.
    Stock, the engine would produce 502bhp, but Cobb had his unit modified and on the test bench it was able to develop 564hp. As with all racers of the time, the block was front longitudinally mounted. The cavernous capacity is matched to a disarmingly low rev limit of just 3,000rpm, meaning there are acres of torque: 1,184lb ft is estimated, with the optimum power of 530bhp delivered at around 2,500rpm.
    A pair of thick leather straps keep the big vented bonnet panels in place.
    Ignition is provided by twin Watts magnetos, controlled by, of all things, basically a light-switch housing. Getting the engine turning over was something even more simple: pushing. This meant – and still means – that getting the Napier-Railton firing requires several mechanics putting their backs against the two-tonne machine.
    Once rolling, the rear wheels are driven through a bespoke Moss three-speed crash gearbox with no reverse, cantilever mounted, running through a Borg & Beck single-plate dry clutch.
    To keep the beast of an engine running requires a whole lot of fluid. The Napier-Railton originally mounted a 65-gallon petrol tank that took 10 minutes to fill.
    Oil tank capacity is 15 gallons (the engine itself utilised dry sump lubrication) of Castrol GP50 and the cooling system requires 12 gallons of 25 percent Bluecol antifreeze solution.
    The bonnet has several caps dotted over it for the various filler tanks, which are themselves little pieces of metalwork art.
    Wooden rods are stored in the cockpit for checking petrol and oil levels.
    These are simply retracted out of their brackets and dipped into the relevant tanks, using the marked scale as a measure.
    By the time the Napier-Railton was being designed, the rigours of racing around Brooklands were well known: the new car would be based on a heavy duty ladder chassis with a pair of underslung live axles, and variable-rate hydraulic dampers at the rear adjustable from the cockpit. Twin cantilever leaf springs sat outboard either side at the rear, delivering a meaty four-bar set-up necessary to cope with Brooklands’ notorious bumps.
    The front springs were semi-elliptical with outboard friction dampers, which were also installed inboard the rear. The mechanicals are extremely sturdy, which was absolutely required for the extreme operating conditions of the car, but at the same time have a beautiful, sculptural quality.
    It’s the same all around the suspension parts of the car: it’s like an exhibition of Steam Punk flourishes…
    …matched with hardcore post-Victorian industrial design.
    Andre Hartford Shock Absorbers were de rigueur at the time, an early form of damper. They worked by the friction created from the stack of disks inside the unit held together by a spring and bolt – an external dial showed the approximate setting in use.
    As we’ve already seen, keeping in contact with the track was always a major issue, despite the damping. On the odd occasion when there was rubber on concrete, it was through bespoke tyres developed by Dunlop; treadless rubber in various sizes for 20×7.5-inch to 35×6-inch sizes were used, depending on conditions and the type of event. The car currently runs on modern Blockley rubber: 21×6.75/7. Blockley was founded about a decade ago by historics racer Julian Mazjub specifically to create authentic rubber for pre-war cars.
    The cockpit was a hostile place. Refined, comfortable, calm – none of these words would be appropriate. The Napier-Railton would reach a top speed of 168mph down the Railway Straight. Cobb would be precariously perched in the car – maybe ‘on’ would be more appropriate, although with the fared bodywork around the cockpit and small air-deflecting windscreen he was more embedded in the car than most of his competitors in theirs. On driving around Brooklands, he said it was like “Seeing how far one can lean out of a window without falling out, and therefore somewhat risky”. That’s some understatement, especially in mind of the open side of the car, lack of belts and armchair of a seat.
    Getting up to nearly 170mph was one thing – stopping was another. Thankfully, for the most part, where Cobb was going he wouldn’t need front brakes. 16″ drums were originally fitted to the rears only, controlled by a foot brake, with a hand brake connected directly to the transmission via expanding shoes in a drum behind the gearbox.
    As soon as the car drove out of the Brooklands workshop in 1933 it was clear that it was something special – as long as Dunlop could produce the requisite rubber that could withstand the forces. In the Napier-Railton’s first event in August 1933, Cobb set a new standing start lap record of 120.59mph and a flying lap of 123.28mph, winning the race by 2.6 seconds. His next outing took the speed to 137.2mph, a new Class A record. Cobb took the car to the Montlhéry oval near Paris for his first attempt on the 24 Hour record: tyre trouble interrupted that run, but he still broke the 200-mile speed record (126.44mph average) and a multitude of other lower distance records.
    In 1934 the Napier-Railton returned to Monthlhéry: this time Cobb’s run was ruined by the small matter of the Napier going over the edge of the banking… But back in one piece and back at Brooklands Cobb clocked up 143.67mph in the Class A standing-start mile record and upped the lap record once again, taking the lap record from Birkin after setting a 139.71mph lap. Next was a trip to the Utah Salt Flats in 1935: the Napier-Railton took the World 24 Hour record and for good measure also took every other record between one and 23 hours.
    Returning home again, Cobb won the 500 mile race, setting a new speed record of 121.28mph in the process which remained the fastest average speed for a 500 mile race until the 1949 Indianapolis 500. He then set his Napier-Railton to crushing every other record at the track: fastest short and fastest long distance races; fastest standing start lap of 120.59mph… But the Outer Circuit lap was still the ultimate target, and four times he upped the average speed.
    On the 7th October 1935 Cobb made another speed run on a damp track: his Dunlop tyres lasted only two laps, but he somehow set a lap of 143.44mph, with a top speed of 151.97mph showing the Napier’s barely abated speed despite the treacherous conditions. It was a lap that would never be beaten.
    Contemporary video is naturally scarce, but this clip gives some context to what that speed meant: Brooklands was insanely bumpy even when new, with no barriers and a hilariously dangerous mismatch of car sizes competing against each other. And we worry about prototypes and GT cars nowadays…
    The Napier-Railton wouldn’t go faster at Brooklands, but in 1936 it returned to Bonneville and maintained a 168.59mph average over a 100 mile run. The following year Cobb gave the Napier its last race outing at Brooklands in the final 500 run there and won, before turning his attention to the Land Speed Record. He would become the fastest man on earth in 1939 when he shattered the LSR in his Brooklands-built Railton-Special, reaching 326.7mph at Bonneville, and in 1947 he went faster still, hitting 398.82mph
    But the Napier-Railton lived on: its fame meant that it was still a darling for the public, and it appeared on film even as late as 1949 in the Ava Gardner film Pandora And The Flying Dutchman. After Cobb’s death in 1952 during an attempt on the World Water Speed Record at Loch Ness, the Napier-Railton was sold on and used to test aircraft braking parachutes at Dunsfold aerodrome for the RAF in the 1950s: Dunlop callipered disk brakes were fitted to the rear wheels, which it still has now.
    After its military service ended the Napier-Railton returned to private hands and was again raced in the 1950s, but displayed at the National Motor Museum in Beaulieu in-between times. During a restoration in the 1970s it was confirmed that it had the same original engine from 1933; it was sold twice more in the ’80s (owners included the chairman of Aston Martin) and ended up in Germany, before being restored again in 1997 and loaned to the Brooklands Museum and run at the Goodwood Festival Of Speed.
    In 1998 it was offered to the Museum and purchased with help from a group of benefactors that included Rowan Atkinson, Ron Dennis, The Earl Of March and Tom Walkinshaw, and since then the Napier-Railton has been at home. Where it belongs. It’s still regularly run out, both at Brooklands and at events round the UK, and continues to draw admiration and love from all who see it. It’s a magical car: a living, relevant piece of automotive history.
    I present: the Napier-Railton.

    NAPIER-RAILTON
    1933
    Owned by the Brooklands Museum
    ENGINE
    Napier Lion Type E89 Series XIA
    24-litre W12
    Double overhead camshaft, four valves per cylinder
    Four throw crankpin with three connecting rods on each pin
    Dual Magneto ignition
    ENGINE MANAGEMENT/ELECTRONICS
    Claudel-Hobson carburettors
    Champion D16 Sparking Plugs
    TRANSMISSION
    Walker steel flywheel
    Open Borg & Beck single-plate clutch
    Three-speed non-synchromesh Moss gearbox
    Hardy Spicer prop shaft
    Fully floating back axle with differential
    ENV final drive with a ratio of 1.66:1
    SUSPENSION/CHASSIS
    Front: Semi-elliptical Woodhead leaf springs
    Rear: Dual cantilever with Luvax hydraulic dampers
    Underslung axles
    Hartford shock absorbers
    BRAKES
    Dunlop six-cylinder disks at rear
    Transmission-operated handbrake
    Ferodo linings
    WHEELS/TYRES
    Rudge-Whitworth wheels
    Dunlop 35×6″-20×7.5″ (period)
    Blockley 21×6.75/7 (current)
    FLUIDS
    15-gallon fuel tank (Shell 95 Octane unleaded pus Castrol additive)
    15-gallon oil tank (Castrol GP50)
    Dry-sump lubrication
    Rear-axle oil sump
    12-gallon cooling system
    CABIN
    Bluemel steering wheel
    Jaeger instruments
    BODY
    Thomson & Taylor designed, Nutting Gurney built bare aluminium body
    PERFORMANCE
    564bhp@2,350rpm
    1,184lb-ft of torque
    Weight 4,518lb (2,054kg)
    Overall length: 16’3″
    Wheelbase 10’10″
    Track 5’3″

    Jonathan Moore
    from SPEEDHUNTERS