2023 Author: Eric Donovan | [email protected]. Last modified: 2023-05-21 15:44
In the past, an automatic was frowned upon by sporty drivers. Over the years these transmissions have become socially acceptable and are increasingly replacing the manual switches.
By Holger Holzer
For a long time the classic manual transmission was the measure of all things for sporty cars. Anyone who moves a lot of horsepower wanted to tame it with a strong hand. Complete control over the vehicle is what makes it so attractive. However, this is paid for by the need to switch gears frequently in city traffic. An automatic was nevertheless frowned upon by sporty drivers for a long time. In the meantime, however, these transmissions have developed massively and are increasingly finding their way into super sports cars. The range of modern automatic variants ranges from sequential transmissions to classic automatic torque converters to double clutches.
AMG unrivaled
The so-called multi-clutch transmission goes to work without competition. The technology, which was previously only available for the Mercedes-Benz SL 63 AMG super sports car, offers extremely sporty starting behavior and enables very quick gear changes. The transmission developed by Mercedes-Haustuner AMG combines the advantages of the automatic converter with those of the increasingly popular double-clutch transmission. Its structure is similar to that of a conventional planetary gear, only that a special clutch is used instead of the torque converter. The multi-plate clutch developed by the transmission specialist ZF runs in an oil bath that keeps the temperature in the housing low and can therefore also transfer particularly high torques without wear - the V8 engine of the SL 63 AMG delivers up to 630 Nm shortly after starting. With the so-called HCC clutch, the usual slip losses of the converter are reduced, and the comparatively lower weight also reduces the mass inertia.
At the same time - unlike with a dual clutch transmission - individual gears can be skipped when shifting up or down. And this is used extensively in the SL 63 AMG in order to achieve better acceleration. The advantages of the technology are also noticeable when starting up. Such toxic agility is not desired in comfort-oriented cars, so the multi-clutch transmission will probably be reserved for particularly powerful sports cars.
DSG in trend
Other manufacturers rely on less exotic, but also powerful automatic transmissions. In addition to the classic automatic torque converter, which has lost its original unsportsmanlike nature in recent years, the dual clutch transmission is also gaining in popularity. After the large-scale debut of the technology, often abbreviated as DSG, in the VW Golf, more powerful versions for sports cars also became acceptable.
The dual clutch transmission shifts particularly quickly because it has two clutches, one of which is responsible for the power transmission, while the other has already preselected the next required gear. The gear change itself takes place by alternately closing and opening the clutches, which only takes milliseconds. The elaborate construction also works without any loss of traction and is therefore particularly sporty and comfortable. DSG technology is offered for the Porsche 911, which uses a ZF system, or in the BMW M3, which uses Getrag technology. Even the fastest series sports car in the world, the Bugatti Veyron, shifts with a double clutch from Ricardo. However, since these gear boxes are elaborately designed in order to be able to transmit the high speeds and torques,they cost a hefty surcharge compared to the alternatively available automatic converter.
Shift paddles on the steering wheel
The sequential transmission, which has long been the most common automatic variant in sports cars, is now disappearing. The technology, which is closely related to the conventional manual transmission, was and is offered by Maserati, Lamborghini and BMW. The transmission is constructed like a conventional manual gearbox, but the clutch and gears are controlled electrically or electro-hydraulically. The driver therefore does not have to operate the clutch pedal or gearshift lever himself, but the gear changes do not take place without an interruption in traction, which the passengers sometimes notice from the rough body nod. This solution is therefore not ideal, which is why most manufacturers now favor other technologies.
Regardless of which automatic variant you choose, the gears can also be changed there by hand if you wish. This usually works using paddle shifters on the steering wheel so that the driver no longer has to take his hands off the wheel. (mid)
