New One Make Racing Series in Australia
An exciting new one-make motor racing series, the Mitsubishi Mirage Cup, will start on July 18. The identical specification Mitsubishi Mirage race cars equipped with high performance Mivec variable valve timing power plants will all race on Yokohama 195/55R 15 size road-legal AO 32 R production car race tyres. The Mirages will have 130kW of power and be prepared and maintained under the supervision of Mitsubishi Ralliart Australia to ensure that all will hit the track in equal trim. The 1999 Mitsubishi Mirage Cup will be staged over six rounds starting at Oran Park on July 18, and will include a round at the AMP Bathurst 1000 at Mount Panorama on October 3.
New Holden Statesman and Caprice
The new models introduce a totally new exterior design and significant engineering advancements. Taking their cue from the VT Commodore, Holden designers have created a distinctive appearance, characterised by "a combination of formal detailing and clean, swift surfaces, is accentuated by a long, low profile flowing up to a high rear deck".
The advantage of extra length afforded by the 2939mm wheelbase translates into accommodation of limousine proportions and comfort. The new Statesman and Caprice models have more rear legroom (1099mm) than any other passenger car on the Australian market. Interiors are all-new with specific and traditional seat designs, new instrument facia, and a new interior trim colour (shale). Luggage capacity of 560 litres is the biggest of all passenger sedans on the Australian car market.
Buyers may choose from a selection of three engines: the 3.8 litre ECOTEC V6, the Supercharged V6 and the new GEN III 5.7 litre alloy V8. The advanced alloy V8 brings significant improvements in power, torque, vehicle performance, reliability and durability, and refined noise and vibration (more tech details on this engine below). It is offered as standard on the Holden Caprice and is optional on Statesman.
A stiffer body structure, longer wheelbase (2939 mm) and wider track (front 1559mm, rear 1577mm) give improved stability. The lighter weight of the new GEN III alloy V8 engine also relates directly to improvements in handling agility and responsiveness. The semi trailing arm rear suspension now incorporates a self-levelling system as standard on both models. Both models have new 16x7 alloy wheels, specially developed Bridgestone tyres, and a more powerful brake system.
Traction control is standard on both models across all three engine options and is tuned for Australian conditions; the latest Bosch 5.3 anti-lock brakes and a revised, continuously variable, speed-sensing Variatronic power steering system are also used.
The New Holden V8
The GEN III engine is one of a family of all new V8 engines that have evolved from the same heritage that produced the Chevrolet "small block" V8. This was the most successful North American engine produced, with production volume in the order of 60 million units.
The design involved building on the inherent strengths of the original small block design, with the objectives of meeting both light commercial and passenger car customer requirements and competitive challenges while also meeting the increasing legislative requirements of emissions and fuel economy. The final design of the passenger car variants for Corvette, Camaro/Firebird and Statesman/Caprice evolved into an all-aluminium 5.7 litre V8 engine with virtually no commonality with its V8 predecessor. A value analysis performed to weigh the numerous factors including mass and packaging efficiency and cost and low end torque requirements, resulted in the selection of an enhanced OHV push rod engine design.
Substantial increases in power and torque have been achieved with the engine. The primary features enabling these increases have been the focus on engine breathing through low restriction intake and exhaust systems, in conjunction with high flow cylinder heads and an enhanced valve train.
Where feasible sealing surfaces are in a single plane and utilise moulded-in-place gaskets. Sealing surfaces and sensors are located away from submerged areas. The engine block and front and rear covers feature a limited number of threaded oil plugs in place of cup plugs and there is no oil or water in contact with the inlet manifold. The cylinder head sealing system has been improved with a new block, head and gasket design. The new design includes stiffer components and longer head fasteners that thread deep into the back bone of the block ensuring the desired clamp load with minimal bore distortion.
Minimising engine noise and vibration harshness was an objective of the engine design to complement this characteristic in today's refined vehicles. The engine block design set the stage for the theme of increased stiffness and reduced vibration that has been carried throughout the engine. A deep skirt block, six bolt main bearing caps, revised firing order, structural oilpan, raised rail cylinder heads, planar valve train and direct mount accessory drive are some of the notable enhancements made to reduce noise, vibration and harshness. This was accomplished while reducing overall mass. The major fuel economy initiatives for this engine were focused on friction reduction.
Packaging, mass reduction and high stiffness were the key drivers in the design of the cylinder block. The casting is aluminium with cast-in-place iron bore liners. The bottom end features a deep skirt with five main bearing caps, which support the crankshaft using four vertical and two horizontal bolts per cap. A structural die cast aluminium valley cover and upper deck rails tie the two banks together, increasing torsional and bending frequencies.
The aluminium cylinder head features replicated ports and combustion chambers ensuring balanced cylinder to cylinder air and fuel distribution, which in turn enhances emission control capability. A four bolt pattern for head attachment provided freedom for the high flow inlet port design and by threading these bolts deep into the cylinder block bore, distortion has been minimised. The corners of the cylinder heads are vented to maintain an uphill purge path for the water jacket. This allows air and vapour to exit the heads easily and move to a pressurised recovery vessel located in the engine compartment.
The engine was designed with a conventional over head valve, push rod valve train in order to maximise the packaging efficiency and provide optimum system cost. This layout has been optimised from a mass, friction and stiffness standpoint, thereby enabling it to meet stringent technical requirements aimed at achieving engine performance, noise, fuel economy and emissions goals. In order to maximise valve train stiffness; a completely new geometry was developed which is virtually planar in both the longitudinal and cross car directions with push rod angles of less than one degree relative to the lifter bore centre line. The camshaft is driven via a traditional sprocket and roller chain. Each of the components in the valve train was carefully optimised to provide maximum stiffness with the lowest moving or effective mass. The valve train has proven capable of reliably producing very aggressive valve events, which generate limiting speeds in excess of 6000 rpm.
The nodular iron cast crankshaft is internally balanced and fully counter weighted. It features variable radii undercuts which increase available bearing area; and rolled fillets for improved fatigue strength. The firing order was revised from the traditional set up to reduce crank arm stresses and to improve main bearing performance. Main journals 2,3,4 and 5 incorporate a drilled hole to enhance crank case breathing and to reduce mass.
A pre-assembled two piece 24x encoded crankshaft position-sensing ring is located at the rear of the number eight counterweight. This position was selected to minimise angular position error from crankshaft torsional deflections. The thrust bearing is centrally positioned to minimise the effect of thermal growth difference between the aluminium block and iron crankshaft.
The connecting rods are made of a powder metal alloy, which is hot forged as a single unit. The big end journal is "fracture split" ensuring a multi faceted joint line and perfect re-alignment of the cap and bearing.
The inlet manifold is made of glass filled nylon and only handles air. With this design there is no water crossover and as the top of the engine is fully sealed there are no contact or sealing requirements for engine oil. The composite material was chosen over aluminium for improved volumetric efficiency and reduced mass. The insulating characteristics of the material improve both the volumetric efficiency of the airflow by maintaining a cooler charge as well as the thermal isolation of fuel system components mounted onto the inlet manifold. Reduced heating of the fuel system components coupled with a limited fuel recirculation feed system has provided enhanced fuel control during extreme temperature operation.
In line with the overall quality and noise objectives the engine lubrication and sealing system received considerable attention. The aluminium oilpan is designed as a structural member enabling full circle attachment of the transmission for enhanced beaming stiffness. Cast in oil dams and windage and anti surge baffling ensures that even the most severe manoeuvres will not result in loss of oil pressure. A compact, high efficiency Gerotor oil pump, driven off the front nose of the crank supplies oil to the engine. Single plane, controlled compression, aluminium carrier gaskets are used to provide a uniform sealing medium for the front and rear covers, oilpan and valley cover. The front and rear crank seals are state of the art teflon/viton lip seals, neither requiring lubrication prior to installation.
For this engine, the ignition system is treated as two sub-elements. The first is energy delivery and the second engine position sensing. To maximise the efficiency of the coil energy delivered to the spark plug gap, a coil-near-plug concept with short secondary leads was selected. This eliminates losses caused by mechanical switching through a distributor and long secondary leads.
A dual sensor concept is used to establish engine position. One sensor is used to read the target wheel located on the crankshaft, which permits quick identification and location of individual cylinders for precision spark and fuel delivery. The second sensor is used to determine which half of the engine firing sequence is operating. Twin knock sensors mounted in the valley cover enable achievement of optimum spark timing.
To further enhance the noise and vibration character of the engine the accessory system has been designed with the power steering pump and alternator decoupled from the air conditioning compressor; and features dual drive serpentine belts with slack side automatic tensioners. The accessory units are near direct mounted to the engine to optimise structural stiffness and quiet operation.
The significant performance, economy and mass gains that have been achieved with this engine over the previous Holden 5 litre V8 are:
- Peak engine power is increased by 23 per cent and peak torque by 11.5 per cent
- City cycle fuel economy has been improved by 13 per cent and highway by 11 per cent
- Performance times have improved by 13 per cent for the 0-100 km/h per hour mark and 5 per cent for 0-400 metres.
- Engine mass is reduced by 18 per cent to six cylinder levels.
Coupled to the engine and recalibrated to match the output torque characteristics is the carryover 4L60E automatic transmission with a new high efficiency 300mm torque converter, the final drive ratio is unchanged at 3.08:1
Xsara Supercar
Citroen has released the first pictures of its 310hp four wheel drive six speed Xsara supercar with which it plans take on the World Rally Championship in 2000.
Following its unique success in this year's World Rally Championship, where it became the first ever car maker to win a World Championship Rally with a Formula Two front wheel drive car, first in Spain and then, with a crashing 1-2 victory in Corsica, the French car maker has now set its sights on the World title.
Based on the three door Citroen Xsara Coupe, the Xsara World Rally Car is powered by a turbocharged version of the 2.0 litre engine sold in the Citroen Xsara in Australia. The 310hp it produces its sent to all four wheels via a six speed sequential gearbox and three active differentials. The wheels are massive 8x18 alloys, with Michelin 20/65 -18 tyres. Braking is provided with pads with six pistons at the front and four pistons at the rear acting on ventilated and cross-drilled disk brakes.
With a weight of just 1230kg, performance is said to be prodigious and we're waiting eagerly to hear of Citroen's plans for a road version...
Alfa 166 Coupe?
Italian styling house, Bertone has revealed the Bella, a unique four seat coupe prototype based on the Alfa Romeo 166 saloon due for launch in Australia this August. Built on the platform of the Alfa Romeo 166, the Bella has the 3.0 litre 166kW quad cam V6 engine to provide exciting performance and the prototype car is fully functional. As bonus, it can also take the full range of Alfa Romeo engines, enabling it to offer a range of versions from the 2.0 litre 114kW Twin Spark engine to the V6 should it go into production.
Quickies
- Ford Australia won the automotive section of the Teleperformance "Grand Prix Customer Service Awards", outpointing fellow finalists BMW and Audi.
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