Wednesday, September 30, 2009

Fiat 500 transmissions: 5 or 6 speed, Dualogic or MTA...





The Fiat 500 comes with a wide range of reliable, robust, sophisticated gearboxes: one is a mechanical unit (with 5 speeds for the 1.2 and 1.3, and with 6 speeds for the 1.4), the other is of the sequential robotized type named the Dualogic. The 500 Abarth comes with a heavy duty 5 speed and the 500 Abarth Assetto Corse a 6 speed extreme duty transmission. The 695 Abarth "Tributo Ferrari" has a robotized version of the normal 500 Abarth transmission dubbed the MTA.

Below is a list of the model numbers and technical specifications of the various transmissions fitted to the Fiat 500 and Abarth versions:


Fiat 500 with 6 speed manual



C514: Fiat 500 5 speed (1.2L motor)/6 speed (1.4L motor)
Max Input Torque: 150 Nm
Center Distance: 170, 182 mm
Length: 362 mm (5-sp), 410 mm (6-sp)
Mass: 33 Kg (5-sp), 35 Kg (6-sp)



Fiat 500 with Dualogic transmission



C514 MTA (Manual Transmission Automated): Fiat 500 with Dualogic
Max Input Torque: 145 Nm
Center Distance: 170 mm
Length: 362 mm (5-sp)
Mass: 42,5 Kg
FPT Electro hydraulic add-on, S-Cam


Fiat 500 Abarth with heavy duty 5 speed manual



C510: Fiat 500 Abarth, Fiat 500 Abarth esse esse
Max Input Torque: 206 Nm
Center Distance: 181 mm
Length: 380 - 395 mm
Mass: 36 Kg


695 Abarth "Tributo Ferrari" with paddle shifted 5 speed MTA



C510 MTA (Manual Transmission Automated): 695 Abarth "Tributo Ferrari"
Max Input Torque: 206 Nm
Center Distance: 181 mm
Length: 380 - 395 mm
Mass: 45 Kg
FPT Electro hydraulic add-on, X-Y


Abarth Assetto Corse with extreme duty 6 speed transmission*



M32 6 speed: Abarth Assetto Corse
Max Input Torque: 320 Nm
Center Distance: 197 mm (M32)
Length: 332 mm
Mass: 47 Kg (M32)
Reverse synchronized





The mechanical gearbox is very compact with a lot of attention paid to its shifter feel. This was made possible by the reduced inertia of the driven clutch plate and the introduction of new seals. The gearbox configuration is transverse with two cascade shafts, while the speed control is internal, with four selection levels.



Fiat C514 transmission cutaway view



The external drive is dual hose type, which filters out engine running roughness and vibration transmitted by the engine to the gear lever. The gears have teeth with extra covering, as well as fifth speed and final drive pairs that are given an extra finish after heat treatment (this improves quiet operation). The gearbox housing is light and absorbs noise efficiently, and has been fine tuned using the Finite Element Method.

The mechanical gearbox of the Fiat 500 has a �syringe� mechanism that prevents the involuntary engagement of reverse.

Dualogic

Dualogic shifter


Magneti Marelli Powertrain produces robotized transmission gear or MTA(Manual Transmission Automated), that consist of the transformation of a regular gear box where the manual transmission is replaced by an Actuation kit (plug-in) electronically controlled by a Transmission Control Unit (TCU)

This system allows:
�Automatic gear shift
�Automatic clutch

In this way the driver has the following options:
�Possibility to choose between manual or automatic transmission
�Manual transmission by joystick or at the wheel
�No more clutch pedal
In addition all the information can be displayed on the dash board for a deeper awareness of the driver.

The Dualogic transmission is available on the 1.2 8v and 1.4 16v versions of the Fiat 500. The 695 Abarth "Tributo Ferrari" is equipped with a similar system but is called MTA (Manual Transmission Automated) and is controlled by a race-inspired paddle gearshift.

The Dualogic and the MTA automates the clutch and gear lever controls by means of an electro hydraulic servo, but maintains all the advantages of a dry clutch and a mechanical gearbox (weight, sturdiness and reliability, low energy consumption).

This sophisticated system improves the performance of the manual mechanical transmission components and increases driving safety because it avoids errors by the driver and prevents faulty manoeuvers of the transmission system.

There are two operating modes: semiautomatic and automatic.

The first adopts the most advanced control strategies to guarantee the best performance. Gears are engaged using the lever on the facia. Because there is no clutch pedal, the device is controlled simply by moving the lever: forward to change up (toward the �+� symbol), back to change down (toward the �-� symbol). A simple push is sufficient to ensure the transmission makes a fast, accurate gear change.


Dualogic/MTA controller



This is how the Dualogic transmission functions in semiautomatic mode. Most of the electric signals reach the control unit by CAN (Controller Area Network) and can be grouped in two large subgroups. In one, the data from the gearbox area, which make it possible to identify the engagement position, the selection, the clutch, and the operating pressure of the hydraulic kit, as well as the rotating speed of the clutch.

In the other, all the signals coming in from the control lever on the tunnel or the levers on the steering wheel (which are optional), that let the driver decide when he wants to change gear, and those from the other systems on the Fiat 500 (for example, the engine and braking system), which help to define the gear change precisely and repeatably. For example, coordination with the engine control unit makes it possible to change up without having to release the accelerator pedal or to automatically increase engine speed when changing down (double de-clutch).

Using these two groups of signals, the Dualogic gearbox can manage gear changes in a comfortable or sporty way, in the manual or automatic mode, interpreting the driver�s needs by analyzing the pedal position and the engine speed.



Once the engine on the Fiat 500 is started, any pressure on the brake pedal confirms that the driver is at the wheel, and enables first or reverse to be engaged (on a slippery surface it is also possible to set off in second). And to guarantee safety and prevent incorrect gear engagement, the system engages neutral automatically when a door is open with the engine running. The Dualogic device also prevents errors that might damage the engine or gearbox, by notifying the driver of emergency situations or incorrect maneuvers with warning lights and beeps.

The automatic mode of the Dualogic system offers two settings on the 1.2 version: Normal and Economy.

The Normal setting provides outstanding driving comfort, with brilliant acceleration and gear changes in all conditions. The Economy setting, on the other hand, is used to reduce fuel consumption, while still maintaining outstanding handling and comfort.

On the version for the 1.4 16v engine, the two settings are Normal and Sport (with the Sport button on the facia). The Sport setting activates a faster gear change logic that minimizes the torque gap and thus makes the car more �fun to drive� for the driver.

In automatic mode, the system recognizes the road gradient (by means of a software algorithm) and modifies the gear shift point to ensure the best possible compromise between the driver�s needs, ground conditions and vehicle situation (speed and engine rpm).

Another feature peculiar to the Dualogic gearbox is its ability to measure the vehicle deceleration and adapt gear changes accordingly. For example, in semiautomatic mode, and particularly with a sporty driving style, the system changes down when the driver asks for a lower speed to take a corner with more gusto. In automatic mode, the system anticipates the change down so that the driver has the best speed to maintain the level of comfort or fuel economy.

The Dualogic system is the best compromise for drivers who prefer the enjoyment and entertainment of a manual shift, but like to know they can count on the convenience of an automatic.

With help from Fiat Group Press/Magnetti Marelli

*photo courtesy of Archivio Perini

No comments:

Post a Comment