ALFA ROMEO 156 2.0 SELESPEED
FROM FORMULA ONE TO THE STREETS OF SOUTH AFRICA
Italian sporting car manufacturer, Alfa Romeo, has brought Grand Prix style gearchanging to the realms of on-road sports saloons with a new version of its award-winning 156, called Selespeed.
The new 156 2.0 Selespeed will now add innovative excitement to the existing local range of 156, the 2.0 Twin Spark and the 2.5 V6 24V.
The 156 Selespeed has the same specification levels as that of the 156 model 2000 which is equipped with side airbags, an armrest between the front seats, a steering wheel and gearknob in leather.
Two buttons on the steering wheel, a sequential gear lever on the transmission tunnel and a fully automatic transmission function, distinguish this new 156 Selespeed as it pushes back the frontiers of transmission technology.
mont blanc pens slimming gel botanical tiffany sale slimming gel victorias secret outlet pandora jewellery cheap beats by dre
Once the vehicle is in motion, the manually actuated five-speed transmission allows for gearchanges to be made without the driver's hands ever leaving the steering wheel. There is no clutch pedal and no absolute need for the driver's foot to come off the accelerator. Operated by advanced computer software, Selespeed releases the clutch automatically, brings the engine and gears to the same speed and then re-engages the clutch in a fraction of a second.
The 156 Selespeed driver thus has the choice of razor-sharp gearchanging, either via integrated push-button controls on the steering wheel or the sequential gear lever.
Developed by Alfa Romeo's engineers in conjunction with Magneti Marelli, manufacturer of the transmission package, Selespeed comes as a logical response to the company's recognition that Alfa Romeo customers have a keen interest in technological innovation.
The 156 Selespeed has a fully electronic 'drive by wire' throttle, which means that the software can provide exactly the correct engine rpm to ensure smooth gear engagement during any downchange - the electronics perfectly matching engine and road speed every time.
Selespeed does away with the clutch pedal; it guarantees easy, fast and crisp gearchanges that are notably smooth, a relaxing fully automatic transmission when in 'City' mode, and promotes safety because the steering wheel is under full control even during gearchanges - the driver never has to remove a hand to reach the gear lever.
HOW SELESPEED WORKS
In technical terms, Selespeed is a manually operated electro-hydraulic gearbox with an automatically activated clutch mechanism. It implements the gearchanging process in a rapid, fully automatic manner. Decisions over which gear is to be engaged are left to the driver, and three actuators intervene to carry out the actions that are normally performed during conventional gear shifts; one controls the clutch, another controls engagement and a third controls gear selection.
A fourth actuator is linked to the engine's electronic throttle and manages torque flexibly on the basis of requests received through the gearbox control system. The time taken to change gear is measured from the beginning of torque discharge to the end of torque return. With a conventional manual gearbox, this operation (typically) takes one to one-and-a-half seconds. Selespeed gearchanges take a similar amount of time when the vehicle is driven normally. However, when the driver starts to press-on (i.e. the accelerator is depressed through more than 60 percent of its travel and engine speed is maintained at about or above 5000 rpm), the system shifts gear in half the time: 4-5 tenths of a second - less time than a top test-driver would take using a conventional manual gearbox. The system prevents over-revving, because if the driver hesitates too long, the gearchange is made automatically.
Selespeed thus makes it possible to push the car's overall dynamic abilities to the limit without altering engine performance in any way, on a par with that of the 2.0 Twin Spark. The driver can shift gears neatly and accurately while keeping both hands on the steering wheel, and without having to use a clutch.
Emphatically sports-orientated when required, but also easy to exploit and to live with, Selespeed can work in two modes: semi-automatic and automatic. In the latter, when the 'City' button is pressed, gear shift controls and decisions over which gear to be engaged are delegated to Selespeed, and the driver is left free to enjoy a relaxing drive that is particularly appreciated in town.
Selespeed incorporates an hydraulic power system. An electric pump takes oil from a reservoir to an actuator that generates pressure in the circuit and provides the energy required to move the clutch engagement and disengagement levers, to select gears, and operate the clutch itself.
Because the system needs energy from start-up, the pump begins to operate as soon as the driver's door is opened. The circuit has already reached the required pressure by the time the car is ready to be driven away.
Fuel supply is governed by a dedicated electronic control unit, manufactured by Magneti Marelli, the company responsible for the Ferrari 355 unit. The control unit communicates continuously with the Bosch Motronic unit that manages the engine, and is responsible for processing the driver's requests and converting them to gearchange commands.
To do this, the control unit utilises information such as accelerator pedal position, vehicle speed, engine rpm and torque input. The system is also supplied with data by sensors and potentiometers located at specific points of various drive components, which it also uses to monitor component service status.
The steering wheel is fitted with two buttons: an 'up' control on the right hand side (identified by a '+' sign) for sequential gearshifts during acceleration; and a down control (identified with a '-' sign) on the left for changing down during deceleration.
The lever works in the same way: it is shifted in the direction of motion to change up, and towards the rear of the car to change down.
A 'City' control on the transmission tunnel is used to activate automatic mode. The steering wheel or gear lever controls are no longer required when this mode is selected.
A VDU inset into the rev counter indicates which gear is engaged, 'City' mode, or system faults.
THE DRIVING EXPERIENCE
To start the car, the brake pedal is depressed and an appropriate gear engaged by the driver to set off: first, second or reverse. The gearlever on the transmission tunnel is used for this operation, because the steering wheel controls are not active at speeds below 10 km/h.
The brake is then released and throttle applied to accelerate the car. Once it is travelling at 10 km/h, the driver can change gear using the steering wheel controls, or continue to use the sequential lever. The latter takes priority if both controls are operated at the same time.
The driver can keep the accelerator pedal depressed during gear changes, although smoother shifts can be ascertained by 'feathering' the throttle momentarily during changes. Selespeed controls the engine directly to reduce and then increase torque and adjusts rpm to the next appropriate gear, but gear shift commands are accepted only if compatible with maximum and minimum rpm limits.
Actuator control sequences are also equipped with a time-out function, which allows the command to be repeated if it is not initially successful. The system will attempt to engage the required gear, but if this is not possible, it immediately selects a higher gear so as not to leave the car in neutral.
During the emergency braking manoeuvres, the system detects the rate at which engine speed is dropping (rpm are directly linked to vehicle deceleration because the clutch is still engaged) and automatically changes down through the gears. This operation is carried out only in the case of sudden heavy braking manoeuvres: the system does not replace the driver, but intervenes solely to ensure greater safety.
When the driver opens the throttle to its maximum and pushes the car in a low gear to maximum rpm, the system shifts up a gear by itself. The same thing does not happen, however, if the accelerator pedal is not pressed. In this case, Selespeed recognises that the car is on a downhill gradient and automatically engages the clutch once a set speed has been reached, so as to increase engine braking. Control of the car is restored to the driver when the accelerator is pressed again.
Enthusiasts will soon come to appreciate that the new transmission 'double-shifts' automatically, the electronics perfectly matching engine rpm to road speed, resulting in high quality seamless changes that sound and feel perfect, complete with an accurate throttle 'blip', as though the driver had executed an immaculate 'heel-and-toe' gearchange.
When the driver releases the accelerator at the approach to, say, a cross-roads or traffic light, Selespeed detects an intention to slow right down and automatically shifts down and releases the clutch to prevent the engine stalling. If the driver intends to start off again without stopping completely, the system automatically engages the best gear for pulling away. Selespeed automatically engages first gear when the car stops.
To engage neutral with the car at a standstill, the driver presses the brake and pushes the gear lever to the right. If the accelerator and brake pedals are not touched for one minute, the gearbox automatically makes the same shift. For safety reasons, the driver is prevented from engaging neutral at speeds greater than 40 km/h.
A gear must be engaged before the driver can switch off the engine and remove the ignition key. If the key is turned to 'off' with the gearbox in neutral, a warning buzzer sounds.
The system deactivates itself two seconds after receiving a zero speed signal from the engine and the gearbox input and output - and also after saving operational and test data in the control unit's permanent memory.
Selespeed automatically shifts to neutral when the car is restarted.
Selespeed boasts a series of features designed to prevent the driver making incorrect commands that could create dangerous situations or damage mechanical components.
The driver is also kept up-to-date on system operation and informed when a gear change is impossible. For example, reverse engagement is indicated by an acoustic and visual signal, and another signal notifies the driver when the engine is switched off and the gearbox is left in neutral. A warning light also comes on when transmission oil pressure is too low, and an intermittent sound warns when the clutch is slipping.
Selespeed is also able to test automatically for faults in its components.
156 SELESPEED SPECIFICATION
The Alfa 156 Selespeed is based on the 2.0 Twin Spark version, but differs from it in a number of ways.
Visually, on the exterior, it is easily distinguished by a set of exclusive 16-inch five-hole alloy wheels which are part of the Selespeed's standard equipment.
There is a Selespeed badge at the rear, and inside, there is a new design of leather steering wheel with integrated gearchanging controls, and a VDU set in the tachometer indicating which gear is engaged.
The speed and engine performance of the 156 Selespeed are the same as that of the 156 2.0 Twin Spark. Top speed is 216 km/h, maximum power is reached at 114 kW at 6400 rpm and torque at 187 Nm at 3500 rpm. Acceleration from 0 to 100 km/h, with two people on board and an estimated load of 20 kg, is achieved in 8.6 seconds.
The new Alfa 156 Selespeed will be on sale locally in mid August 2000 at the price of R170,000.00 inclusive of VAT.
Copyright © 2000 Volt Developments. All rights reserved.