Sequential manual gearbox
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A sequential manual gearbox is a type of manual transmission designed for high-performance driving or auto racing, where random access to specific gears is no longer required (or in fact possible).
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[edit] Overview
With traditional manual transmissions, the driver can move from any gear, to any gear, by moving the shifter to the appropriate position. A clutch pedal must be depressed before the new gear is selected, to disengage the running engine from the transmission. In auto racing, this process is inefficient and prone to human error; hence the development of the sequential transmission.
Sequential manual transmissions (sometimes referred to by commercial names such as Jerico transmissions) work by providing the driver the ability to select the gear directly before or after the gear currently engaged, usually by pulling a "paddle" (rocker switch) or (in cases where paddle shifts are banned) moving a lever. For example, if the transmission is in 2nd gear, pulling on the "up" paddle or lever would up-shift, selecting 3rd gear. Conversely, using the "down" paddle or lever would cause the transmission to downshift into 1st gear.
Sequential gearboxes are also used in all modern motorbikes as it is too combersome to have a manual shifter and would take up too much space in the confines of a motorbike frame. The gears are formatted normally as being one down and 4 or 5 up, neutral being in the middle of 1st and 2nd. Having control over the gear shifter with your left foot, this frees up the rider's hands to opperate both the clutch and brake, not having to take his/her hands off the handle bars.
Sequential manual transmissions are true manual transmissions, and should not be confused with automatic transmissions that provide some degree of user shifting input. One commercial example of this type of automatic transmission is the Tiptronic transmission. User shifting input through buttons or lever does not necessarily mean that the transmission is a manual transmission.
[edit] Benefits
Beyond the ease of use from a driver's standpoint, an additional benefit of sequential manual gearboxes is that use of the clutch via foot pedal or hand control can be minimized or completely obviated, especially after coming to speed in first gear. Formula One cars of the 1980's and 90's made the most high-profile debut of this technology in motor sports, and enhanced variations on this theme are still in use in many forms of road racing and drag racing today.
[edit] Use in road cars
The most famous application of a sequential transmission on road-cars would be their use in Ferraris since the mid-nineties. Their system, the most current version of which is called "F1-Superfast," is designed to serve as a link to their Formula 1 efforts. This technology has also trickled down to the cars of their sister company, Maserati where it is known as "Cambiocorsa." BMW also has a system simply called "SMG" (an acronym for sequential manual gearbox), but it is not a true sequential, as gears can be selected out of order.
