How to beat hell out of your vehicles
Page 41
Page 42
Page 43
If you've noticed an error in this article please click here to report it so we can fix it.
Ask IVECO. It knows all about it. To stay competitive, it has to. Steve Gray investigates Fiat's mind-boggling test track in Southern Italy, while Bill Brock penetrates Magirus' facilities high in the German hills
THE jungle of legislation facing vehicle makers today means to stay competitive, they must get the product right from the start. Gone are the days when they could afford to carry out extensive road trials to prove the vehicle over many months, even years.
Testing has to be condensed, but it must be comprehensive, meaningful and accurately reflect the special needs of the various markets into which the manufacturer sells its wares.
In order to carry out these tests out of the gaze of competitors or the public, most major manufacturers have set themselves up with test tracks. These mean that vehicles can be comfortably tested at higher than legal speeds, tested to destruction, and cover far higher mileages more quickly than would otherwise be possible.
Fiat's test track is one with a difference. Its located near Nardo in Southern Italy and is the only one of its size in Europe. Unlike other manufacturers which have fairly small test tracks next to their manufacturing plants, the Fiat one is many miles away — and its size is mind-boggling.
It covers 7 m-sqm (75,349,400sqft) and the main test circuit is a perfect circle measuring 4km (2.49 miles) in diameter, with a circumference of 12.5km (7.75 miles).
Apart from its size, though, the Fiat track is unique in another way, because despite its being owned entirely by Fiat a separate independent company was formed to operate it — the Societa Autopiste Sperimentali di Nardo, or SASN. This means that it can offer the facilities to other vehicle manufacturers, tyre makers or other interested parties.
According to the director of SASN, lng. G. Mininanni, the fact that it is Fiat-owned does not affect its confidentiality with regard to other makers.
The beauty of the Nardo track is chiefly its location. Not only is it far enough away from indust rial areas to maintain secrecy, but it is in a part of Italy which seldom sees rain, let alone snow, mist or any other nasties.
Testing is possible all year round in a more or less equable temperature. Manufacturers from all over Europe can use the track when the highways near their production plants or in their own country are unsuitable.
Mechanical components can be tested — some to overload — high speeds and high mileages are possible as the track has parabolic cross-section to allow sustained performance. divided into six lanes, fot. cars on the outer circumfei and two inner for CV. "Hi off" speeds range from innermost at 80km/h (50mp to 240km/h (150mph) or outermost. At these sp there are no lateral forces so no steering effort is need However, these speeds a no means the maximum. cedes-Benz holds the recor the outer circuit with an inc ble speed of 404km/h (251r achieved with a special s racing car. The track i! appears to be level, but in was designed to simulatE normal type of highway dient.
It is controlled from one t which gives an overall vie the whole circuit. This is la. unnecessary, though, as control tower houses a ma iterised equipment which )nitor a vehicle's performccurately.
exact type of information relayed to the tower and s of lap numbers, kilo; covered, average speed 1, and other basic informa n be collated on an instant it. In addition, it is pos o take measurements of Iperature, water tempera r almost any other data J.
monitors cover the en s and exits, and admission ily be gained by keying-in ;lal key which automatnotifies the tower. SASN poly any necessary radio equipment and sensors to customers to enable any recordings to be made which are required.
Within the circumference there are additional test facilities. These include a vehicle dynamic test area consisting of two straight roads which form a right-angled corner containing a test pad. The two straights are 700m (2,300ft) long and 20m (65ft) wide, while the test pad is 280m (920ft) square.
These can be used for various steering and control tests and the surfaces are said to be virtually free from irregularities which are likely to produce different effects.
A relatively new addition to the SASN test facility is a special track for testing the interaction of vehicle/tyre/road. Situated again within the main circuit, it consists of three different road surfaces which are laid out consecutively.
The first has a soft structure, the second a medium, and the third a hard structure. Sensors and strain gauges are used to measure forces and almost all parameters are taken care of. This particular research element was set up by a co-operative of Fiat, Pirelli, the National Society for the Highways, AGIP petrol and SASN.
To provide a back up for all the test facilities, SASN has three workshops. One is for Fiat/IVECO's sole use, but it can also be let out to customers. The other two are divided into boxes or separate compartments which are rented separately and which ensure privacy for individual manufacturers.
Normal workshop equipment is available, and SASN will even provide personnel, if required.
The cost of building the track — it was started in 1971 and completed four years later — was eight billion lire (£3.5m) but it is estimated that it would cost around three times that if it were built today. Since it was completed nearly another Elm has been spent on new works.
Bearing those costs in mind, it is not surprising that few manufacturers want to build their own and that most — including our own BL — use Nardo.
If the test tracks of the Fiat organisation are impressive, so too are the research facilities in Turin where all Fiat products are evaluated. Sixteen test cells — mixed for petrol and diesel — are equipped with the latest microprocessor controlled data log and alarm systems within the engine test section.
Video readouts or written data can be collected from a myriad of sensors and couplings fitted to engines under test. No recycled air is used, with two inlets and one outlet provided for each cell. Engines are fitted up with test equipment outside the cells, then installed. Some are fitted with a flywheel to simulate inertia, while others are connected to a brake band dynamometer.
Emissions too are analysed via American equipment, which includes smoke sampling. The smoke is mixed with ten to 20 times the same quantity of air in a tube long enough to allow a good mix. Filter papers collect the particles and they are then analysed.
A complete test programme is worked out with the computer controlling engine speed, loads and so on.
Another section of the engine test area is devoted to monocylinder engine work. These are easier to change than multicylinder, but give identical results. Cylinder heads, pistons or injectors can be changed as desired to find solutions for differing problems.
One of the other test cells is a cold cell which can be reduced to —40°C. It is used to analyse engine crank characteristics at low temperatures and also durability cycles.
On the materials side, Fiat uses lasers to both analyse the components themselves and to check surfaces. The deformation of materials under stress is also measured using holograms, which show where likely stress areas are. This helps with final production to eliminate later service problems.
Fiat also has a wind tunnel set up which includes a main tunnel and two climatic chambers — one hot, one cold. The main wind tunnel has a maximum air speed of 200km/h (124mph) through a 3 Osqm (323sqft) nozzle. An axial fan with 1,800kW of power and variable blades is used to provide the draught. Although full-size cars can be accommodated in the tunnel, only half-scale heavy trucks and buses can be tested.
Yaw, roll and pitch can all be checked by means of sensors in the floor pads, which are coupled to the wheels. The other tow wind tunnels have temperature variations of from —50°C to +20°C and —15°C to +50°C, for cold and hot respectively.
These can simulate all possible climatic parameters, with air coming through a 12sqm (129sqft) nozzle. Like its Nardo test track, Fiat allows other makers to rent the wind tunnels. With a 1972 cost of El Om it's not difficult to see why.
IN GERMANY, IVECO is Magirus-Deutz AG, producing buses at Mainz and trucks at Ulm. The marque, identified by a logo closer resembling a modern rocket than Ulm's ancient and the world's tallest steeple, differs from its partners in France and Italy in the sole use of aircooled engines. Magirus too has its own test track facility high in the hills overlooking Markbronn about 9km (5.5 miles) from the modern factory at Ulm.
Though covering only some 55,000sqm (15.5 acres) it contains a variety of test conditions both for onand offroad vehicles. The objective of most of this type of testing is to accelerate stress and fatigue factors which will arise in normal working conditions over a long period. The facilities consist of two smooth asphalt circuits. The largest, with a maximum gradient of 8.5 per cent and curved radius of 100-150m, is used for endurance and highway testing. Running inside and parallel to the smaller circuit which is used by accompanying instrumentation vehicles, the function and endurance test track contains 11 changes in road surface.
Track conditions range from 400mm (15.75in) high bumps, which induce extreme frame distortion, down to 700mm x 20 Omm sine wave profiles, which used with just one side of the vehicle passing over, work the frame and suspension hard.
Other surfaces contain Belgian block with 50mm (2in) deep depressions, light washboard, patched asphalt and deep potholes.
A brake test track is made with different types of surface, giving a range of friction coefficients.
A large rectangular area equipped with water sprinklers is used for steering tests and a concrete, trough, with a water depth of 1.50m (5ft), tests a vehicle's fording ability and water-proofing. Three gradients of 20,25 and 40 per cent can be used for hill restarts and parkbrake tests.
More arduous off-road testing emulates many of the track tests but with mud, water and dust thrown in.
The vehicles conform to a set programme of testing, corn ing a given mileage or testir destruction. Two-thirds of distance is coverec overloaded and one-third is ered empty, generating r severe vibration — the go 20,000km without failure.
Testing continues day in out all the year round, ex when the snow gets too dee'
Back at Ulm, the design CE looks at individual compon in laboratory conditions. HE 400bhp dynamometer can programmed to reproduce s conditions for 4x2 4x4, 6x4 6 x 6 models up to 6m wl base, at speeds up to 12 (75mph), with a maximum of 40 tonnes across an indivi axle.
Other facilities incorporate draulic ram systems contre by electro-magnetic val which can simulate vibrat up to 30Hz. The cylinders, r from one tonne to 40 ton have a stroke of 250mm (1 and are used to improve sus sion and chassis compon with a test programme base information accumulated at testing ground.
Engine, brakes, gearbo seats, otos, pedals, cabs, c sis, steering and many c components come under E. tiny of the development E neer. When tomorrow's vel arrives, he will be respom for the way it performs.