Electrohydraulic manual transmission
Electrohydraulic manual transmission is a type of semi-automatic transmission system, which uses an automated clutch unlike conventional manual transmissions where the driver operates the clutch. The clutch is controlled by electronic computers and hydraulics. To change gears, the driver selects the desired gear with the transmission shift lever, and the system automatically operates the clutch and throttle to match revs and engage the clutch again. Also, many such transmissions operate in sequential mode where the driver can only upshift or downshift by one gear at a time.
Depending on the implementation, some computer-controlled electrohydraulic manual transmissions will automatically shift gears at the right points (like an automatic transmission), while others require the driver to manually select the gear even when the engine is at the redline. Despite superficial similarity, clutchless manual transmission differ significantly in internal operation and driver's 'feel' from manumatics, the latter of which is an automatic transmission (automatics use a torque converter instead of clutch to manage the link between the engine and the transmission) with ability to signal shifts manually.
Use in road cars
In 1984, Isuzu introduced the "NAVi5", a semi-automatic gearbox with electronically controlled hydraulics, for their domestic-market Aska. Initially available with an automatic mode only, the later incarnations added a manual mode. It was operated with an H-pattern shift lever, not a sequential lever or paddles popular in today’s cars.
Ferrari offered the Mondial T model with a clutchless manual, called Valeo transmission. In this system the gear stick of a traditional manual transmission is retained. Moving the shifter automatically engages the electro-hydraulic clutch. This transmission was featured in an episode of Top Gear. In 2017 Toyota unveiled the GR HV SPORTS concept with what looks like a similar transmission.
The most famous application of a sequential transmission on road-cars would be their use in some Ferraris since the late-nineties, beginning with the 355 F1. Their system, the most current version of which is called "F1-Superfast," with shift times of 60 ms is designed to serve as a link to their Formula One efforts. This technology has also trickled down to the cars of their sister company, Maserati, where it is known as "Cambiocorsa". In 1999 Alfa Romeo 156 was the first mainstream car with a sequential transmission derived from the Ferrari system (Selespeed).
BMW offered a system simply called "sequential manual gearbox" (SMG) on the E36 M3(Starting in 1997), and later "SMG-II" on the E46 M3. BMW's first generation SMG was also partly a Magneti Marelli system similar than used in Ferrari and Alfa. The BMW SMG transmission has both automatic and manual shift modes. Inside the different modes there are different programmes, with six settings to control the upshift/downshift speed for manual operation, and five settings for automatic mode. BMW's final SMG gearbox, known as SMG III, was the fastest shifting gearbox at the time (2006), recording a 65 millisecond shift time in its most aggressive mode - a time only surpassed by Ferrari with the 599 GTO (60 milliseconds) and later the Lamborghini Aventador (55 milliseconds).
The 3rd generation Toyota MR2 used Toyota's version, known as the "Sequential Manual Transmission" (SMT).
|Production Year (*)||Manufacturer||Model||Version||Transmission Name|
|1996||Alfa Romeo||156||2.0 TS/JTS/GTA||Selespeed|
|2007||8C Competizione & 8C Spider||-||Q-Select|
|2001-2007||Aston Martin||Vanquish / Vanquish S||All||Sequential Shift Manual (SSM)|
|2006||Audi Sport GmbH||type 42 R8||-||R-Tronic|
|1992||BMW||E36 M3||-||SMG (Sequential Manual Gearbox)|
|2000||E46 M3||-||SMG II|
|2002||E85 Z4||-||SMG II|
|2005||E60 M5||-||SMG III|
|2005||E63/64 M6||-||SMG III|
|2004||Citroën||C4||equipped with a HDI engine||EGS|
|1983||Isuzu||Aska||2.0 (option available from 1984)||NAVi5|
|1985||Gemini||FF (option available from 1986)|
|2003||Lancia||Ypsilon||(option available from 2006)||DFN (Dolce Far Niente)|
|2010||Lexus||LFA||-||ASG (Automated Sequential Gearbox)|
|2001||Maserati||Coupé and Spyder||-||Cambiocorsa|
|2005||Proton||Savvy||-||AMT (Automated Manual Transmission)|
|1999||Toyota||MR2 mk3 (aka MR-S)||-||SMT (Sequential Manual Transmission)|
(*) "Production Year" is the first production year of the entire car (if multiple generations are available, this is the year of the one that introduced the electrohydraulic manual transmission), it's not the first year the electrohydraulic manual transmission was available (because there is currently not enough information available) and it's definitely not the first "Model Year" of the car.
- "Toyota to Unveil GR HV SPORTS concept at Tokyo Motor Show 2017". Toyota. 2017-10-06.
- Neff, John (2007-07-18). "Ferrari reveals F430 Scuderia, not Challenge Stradale". Autoblog.com. Retrieved 2009-10-03.
- Ciferri, Luca. "FERRARI LAUNCHES F1-STYLE GEARBOX ON F355". Automotive News Europe. Retrieved 12 June 2018.
- "BMW 330i SMG". evo.co.uk. Retrieved 2007-05-08.
- Lewin, Tony. The BMW Century: The Ultimate Performance Machines. Motorbooks. p. 137. ISBN 9780760353042. Retrieved 21 July 2017.
- "FAQ E36 M3 3.2". BMW M Registry. Retrieved 2009-10-03.