Evergreen Giant

Author

admin

Evergreen Giant

FEW manufacturers can claim to have produced a ‘classic’ car in the last twenty years, least of all one from a mass producer, but in the quattro Audi can fairly claim to have a car which has become a legend in its own lifetime.

Making its debut at the 1980 Geneva Motorshow, the original plan was for only 400 examples to be built for homologation purposes. To date, however, more than 10,700 have been made with 2400 of them, accounting for almost a quarter of the output, coming to Britain, the model’s most important export market.

To capitalise on the car’s evergreen appeal, Audi has now produced a more powerful 200 bhp, 20-valve head engine to sit in the engine bay of the model’s unmistakably shaped body.

Based on a detuned version of the 300 bhp Audi Sport quattro engine, the 2226cc five-cylinder unit, with a bore and stroke of 81.0mm x 86.4mm, has many features, such as the special surface material on the bearing shells, which derive from Audi’s competition engines, while other parts have been adapted from standard production units. The rigid cylinder block, crankshaft and connecting rods, for example, are taken from the 165 bhp five-cylinder turbocharged engine.

The camshafts are housed closely together in the aluminium Sport quattro head linked by a short single roller chain running in oil. The exhaust camshafts are driven from the crankshaft by means of a toothed belt. The centrally located valves, 32mm intake and 28mm exhaust and sodium-cooled, are smaller than usual which enable a small valve angle of just 25 degrees to allow a more compact combustion chamber shape for better results. Even with the two camshafts, the overall width remains short for a four-valve layout resulting in a comparatively light cylinder head.

The advantage of four valves per cylinder in this engine is not so much the increase in top-end power, but superior cylinder charging, a more efficient combustion chamber, better exhaust emission characteristics, increased miles per gallon, a higher compression ratio and more power and torque.

At 228 lb ft at an engine speed of only 1950 rpm, the torque is exceptional endowing the car with real low-down punch. At 9.3:1, which is surprisingly high for a turbocharged unit, the compression ratio is higher than the older unit at 8.6:1. The power output is in true sportscar tradition producing 220 bhp at 5900 rpm, or 100 bhp per litre and 103 lb ft of torque per litre. Naturally the newly developed low-inertia, liquid-cooled, exhaust-driven turbocharger, charge air intercooler, which reduces the air temperature from the turbocharger to around 60° centigrade, electronic boost pressure control and sequential fuel injection into the intake pipes are all contributory factors in the engine’s performance. A Motronic control unit controls all the engine management functions, such as the

fuel injection, ignition, pinking, turbo boost, lambda-probe mixture control, tank venting, diagnosis and emergency operation, and it automatically adjusts systems according to the data feedback.

Acording to official Government figures, the quattro attains 36.2 mpg at a constant 56 mph. 28.5 mpg at a constant 75 mph and 19.5 mpg in the urban cycle, all the figures significantly helped by a variety of factors: lower pressures ahead of the throttle butterfly; lower exhaust system back-pressure and reduced air and exhaust temperatures help in the part-load areawhile sequential fuel injection helps the engine to run more smoothly.

As with all models in the Audi range, the quattro 20V is designed to run exclusively on ordinary unleaded premium grade 95 octane fuel, and even on 91 octane unleaded fuel, and it has no requirement for the so-called `Supergreen’. Tank capacity is 19.8 gallons, giving a useful 550 + mile range at 75 mph.

The front and rear axles are linked by a Torsen (torque sensing) differential lock which mechanically distributes engine torque on a 50:50 ratio to front and rear axles via half a dozen worm gears. The split, however, can be varied up to 75:25 in favour whichever axle is able to cope with the available torque more effectively, useful on slippery roads, when under acceleration and when carrying heavy loads. To cope with the extra power of the 20 valve engine, the inter-axle differential has undergone some slight revisions.

Although quattros have been fitted with electronic ABS anti-lock brakes since December 1983, it was not until the Torsen central differential was fitted to the model in September 1987 that the brakes and differential could be operated together.

For icy and muddy conditions, the rear differential can be electronically locked with a button on the dash which also switches off the ABS, but as soon as 15 mph is reached, the electronic speedometer sends a signal to disengage the differential lock with the ABS switching itself on again automatically.

Driver and passenger comfort are still high on Audi’s agenda. The leather-faced seats with Jacquard satin upholstery have been improved and are now even more supportive and comfortable, adjustable for height, reach and rake. Both front seats are heated, the temperature set by two small dials on the dashboard. The thick rimmed Audi Sport steering wheel is also leather-covered and is particularly pleasant to handle.

All driver information is supplied by liquid crystal display including an onboard computer which indicates mileage range on current fuel consumption and fuel tank contents. The tachometer is quasi-analog and the speed and trip distances digital. All but the speedometer and clock can be switched off if so desired.

Door trims, storage trays and compartments are all leather clad while the carpet is in hard wearing wool. A genuine four-seater, as opposed to a two-plus-two, the size of the boot is a little on the small side, but it would have been sacrilegious to spoil its handsome lines, a shape that has been retained at the behest of customers.

As would be expected, central locking, powered windows and electrically heated and remote controlled door mirrors and sunshine roof are all standard equipment as are the alloy wheels. The attention to detail is exacting which reflects in the car’s overall build quality.

As with the BMW M5, the car’s performance figures are almost in the supercar league, particularly in acceleration. 0-60 mph takes only 5.9 seconds and its top speed is 143 mph, performance out of reach of the old 200 bhp car. The traction is excellent on all variety of surfaces and it is absolutely roll-free, keeping its poise and balance to the limits of its incredible adhesion. On the launch, Audi bravely let us loose on some Forestry Commission track on a cold, frosty day. A few laps around the woods proved just how brilliant the chassis is. Travelling at speeds that would have

felt very unsafe on any icy asphalt road, the quattro used its huge resources of grip, combined with the 215/50 R15 Pirelli P700s, to speed along the track in absolute stability, wheelspin virtually impossible. It was only when trying a touch of injudicious left foot braking that the tail hung out just a little too far, otherwise the predominant handling characteristic was mild understeer. It was sure-footed in a straight line and although the wind during the day was low, experience with the earlier quattro would indicate that crosswinds would not unbalance it. The assisted steering in all conditions is precise and accurate and is perfectly weighted.

Although the car still retains its ruggedly handsome looks, the slightly flared wheelarches and chisel nosed front, the quattro is no longer the untamed beast of yore. Turbo lag is non-existent, the power delivered in one continuous punch up to the electronic 7000 rpm, the lumpy fivecylinder engine smoothed out to feel as if there were six pistons at work. It is only above 5500 rpm that there is any sort of mechanical noise, otherwise there is just the tyre rumble from the wide tyres and wind noise above 100 mph.

With the extra torque available, there is less need to change down when overtaking, which is just as well for the car does have one flaw: the gearbox. If there is one aspect which lets this 02,995. vehicle down, it is the five-speed gearbox which feels too rubbery and too imprecise for such a well-honed machine.

At least the weight of the clutch is acceptable. Although the test run did not include too much slow speed traffic, the stop-start capabilities of the car were as consistent as any family saloon, the shift from neutral to first free from baulk. For a long time Audi has been associated with advanced engineering and tech nology, and has to date produced over 175,000 quattro versions of its other models, more permanent four-wheel drive cars than any other manufacturer, and yet it is the original quattro model which still captures the imagination. At a time when model lives become ever shorter, the original quattro goes on and on, ever improving, ever more desirable, even after ten years. It is now in a price bracket that puts it with such formidable cars as the Porsche 944 S2, the Jaguar XJS V12 and the Lotus Esprit Turbo, and yet it has its own unique blend of fourwheel drive, four passenger comfort and supercar performance to offer. WPK