Manumatic

Manumatic, a portmanteau of the words manual and automatic, is a term referring to a class of automotive transmission.

Manumatic refers to an automatic transmission that allows convenient driver control of gear selection. For most of automotive history, automatic transmissions already allowed some control of gear selection using the console or column shifter, usually to limit the transmission shifting beyond a certain gear (allowing engine braking on downhills) and/or locking out the use of overdrive gears when towing. Manumatics enhanced such features by providing either steering wheel mounted paddle shifters or a modified shift lever, allowing the driver to enter a "manual mode" and select any available gear, usually in a sequential "upshift/downshift" manner. Different car manufacturers use a variety of labels for their manumatic transmissions, such as 'Tiptronic', 'Geartronic', 'Touchshift', 'Sportronic', 'clutchless-manual' and others.

Some manumatic and semi-automatic transmissions allow the driver to have full control of gear selection, though most will intervene to prevent engine stalling and redlining by shifting automatically at the low end and/or high end of the engine's normal operating range. Hydraulically-coupled Manumatics and most semi-automatic transmissions also provide the option of operating in the same manner as a conventional automatic transmission, by allowing the transmission's computer to select gear changes. A few manumatics also allow an alternate automatic mode, often called "sport" mode, where gear selection is still fully automatic but the transmission will favor higher engine speeds (at which the engine will produce the highest horsepower and/or torque) by upshifting later when accelerating and downshifting earlier when slowing.

Two-pedal operation

The Automotive Products Manumatic and Newtondrive systems are also known as "two-pedal transmissions". They relieve the driver of the need for skill in operating clutch and engine speed in conjunction with the gear change.

Manumatic

A clutch servo powered by the vacuum at the induction manifold operated the automatic clutch - a conventional clutch incorporating centrifugal operation. A switch in the gear lever operated a solenoid valve so that when the gear lever was moved the clutch was disengaged. A control unit made throttle adjustments to keep the engine speed matched to the driven clutch plate and also varied the speed of clutch operation appropriate to road speed.[1]

Newtondrive

The Newtondrive system differed in making a provision for choke control and a cable linkage from clutch operating mechanism to the throttle.

The systems could be fitted to smaller cars such as the Ford Anglia.

Tradenames

Tiptronic

Tiptronic is a registered trademark, owned by German car maker Porsche, who license it for use by other manufacturers, such as Land Rover and the full Volkswagen Group (Audi, SEAT, Škoda, Bugatti, Lamborghini, Porsche and Volkswagen).

Many people use the term 'tiptronic' to refer generically to any type of torque converter automatic transmission that incorporates a manual upshift/downshift feature.

A tiptronic transmission can operate in the same manner as a conventional type of automatic transmission, but also offers the driver an additional method of manually overriding the automatic shift changes. By moving the shift lever into a second operating plane of the shift gate, equipped with two spring-loaded positions: "upshift" and "downshift", the driver takes over most of the gear shifting decisions, which would ordinarily be performed by the transmission's computer. For example, this allows delayed upshifts for increased acceleration, increased engine braking, gear holding in curves, downshifting before passing, or early upshifting for cruising. On some models, the upshift and downshift operations can also be controlled by push-buttons or "paddle shifters" installed on the steering wheel, with an optional display in the instrument panel indicating the current gear selection. Since adding Tiptronic to a semi-automatic transmission involves an additional shift gate into the computer and update to the transmission software, it is inexpensive and lightweight to implement. Although tiptronic transmissions allow the driver a certain measure of discrete control, the tiptronic design is implemented using a torque converter like other automatic transmissions. A true tiptronic transmission is not a computer controlled manual transmission (with a conventional clutch), or semi-automatic transmission. Most tiptronic implementations still make some shifts automatically, primarily to protect the engine and transmission. For example, as used by licensee Audi, the five-speed tiptronic will automatically make the upshift from 1 to 2 when moving off from a stop, even when in manual mode; the transmission then waits for the user's upshift command before proceeding from 2 to 3, 3 to 4 and 4 to 5, although the transmission will still upshift if the redline is approached. On deceleration, the transmission will make all downshifts automatically when close to the tick-over or idle speed, to prevent the engine from stalling at too-low an RPM, although the user can accelerate any downshift that would not exceed the redline.

Most luxury vehicles with a tiptronic transmission have two fully automatic modes: the primary mode, identified as "Drive", "Comfort" or similar; and another, usually called "Sport," which delays upshifts higher up the engine rev range (and will also downchange higher up the rev range) for a sportier driving and enhanced engine braking — at the expense of fuel, wear, comfort, and noise. Furthermore, because modern tiptronic-type transmissions use an electronic control unit (ECU), sometimes specifically referred to as the transmission control unit, the transmissions are able to adapt to the user's driving style through "fuzzy logic". Shift points are tailored to the habits of the driver, through an evolutionary process.

Tiptronic S

The Tiptronic S is an upgrade to the original Tiptronic, with the ability to adapt to driver's behaviour, and also allows driver to change gears without entering manual mode.[3] In manual mode, if there is no driver input for a period of eight seconds, the system reverts to automatic mode.[4] It was used as early as 2000 in the Porsche Boxster.[5]

In the Porsche Cayenne, the Tiptronic S was upgraded to six-speed.[6]

See also

References

  1. ↑ Staton Abbey (ed) Practical Automobile Engineering Clutch Systems p 193-194
  2. ↑ "Twin Clutch SST, Mitsubishi-Motors.com Technology Library". Retrieved 2014-12-07.
  3. ↑ "Porsche Technical Highlights". Carpages.co.uk. Retrieved 2011-07-31.
  4. ↑ "Tiptronic S details". Porsche.com. Retrieved 2011-07-31.
  5. ↑ "2000 PORSCHE BOXSTER". Auto123.com. 2000-01-15. Retrieved 2011-07-31.
  6. ↑ "MotorBar Road Test: Porsche Cayenne S". Motorbar.co.uk. Retrieved 2011-07-31.
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