Electrohydraulic manual transmission
|This article needs additional citations for verification. (November 2009)|
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.
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 F355 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". Alfa Romeo's Selespeed in 1999 was the first sequential transmission in a mainstream car, derived from the Ferrari system.
BMW offered a system simply called "sequential manual gearbox" (SMG) on the E36 M3, and later "SMG-II" on the E46 M3. 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 at 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).
Later, the 3rd generation Toyota MR2 used Toyota's version, known as the "Sequential Manual Transmission" (SMT).
- Alfa Romeo 156 2.0 TS/JTS/GTA (Selespeed)
- Alfa Romeo 147 2.0 TS/GTA (Selespeed)
- Alfa Romeo GT JTS (Selespeed)
- Alfa Romeo 159 2.2 JTS (Selespeed)
- Alfa Romeo Brera 2.2 JTS (Selespeed)
- Alfa Romeo Spider 2.2 JTS (Selespeed)
- Alfa Romeo 8C Competizione & 8C Spider (Q-Select)
- Aston Martin (certain models)
- Audi R8 (R-Tronic)
- 1997 BMW E36 M3 (SMG)
- BMW E46 M3 (SMG II)
- BMW E60 M5 (SMG III)
- BMW E63/64 M6 (SMG III)
- BMW E85 Z4 (Optional SMG)
- Fiat Stilo Abarth (Selespeed)
- Fiat Bravo Brazil (Dualogic)
- 1997 Ferrari F355 (F1)
- Ferrari FXX
- Ferrari 360
- Ferrari Enzo
- Ferrari F430
- Ferrari 612 Scaglietti
- Ferrari 599
- Isuzu Aska (NAVi5)
- Isuzu Gemini (NAVi5)
- Lamborghini Gallardo (E gear)
- 2010 Lexus LFA (ASG)
- Maserati (certain models)
- Proton Savvy AMT
- 2002 Toyota MR2 (SMT)
- Neff, John (2007-07-18). "Ferrari reveals F430 Scuderia, not Challenge Stradale". Autoblog.com. Retrieved 2009-10-03.
- "FAQ E36 M3 3.2". BMW M Registry. Retrieved 2009-10-03.