PRODUCT INFORMATION - Alloytec V6 Transmissions

In VZ and WL models the Alloytec 190 variant will operate with either a new 5L40 five-speed automatic transmission with Active Select or a new six-speed manual transmission.

The Alloytec variant will operate with the current 4L60 four-speed automatic, to which Holden has made significant refinement upgrades.

Five-speed auto transmission (5L40)
The new 5L40 five-speed automatic uses the latest generation production-released hardware strategy from GM.

A team of Holden and GM powertrain engineers based in Strasbourg invested three years of design and development work in this 5L40 transmission. Cold testing in Sweden, altitude testing at Pikes Peak in Colorado and hot testing in Western Australia were part of a development and durability program which resulted in multiple improvements to the original design to ensure that the transmission successfully mates to Alloytec.

Transmission Controller
A new separate T68 transmission controller accurately determines current vehicle operating conditions – such as engine speed, transmission input speed, throttle position, torque converter slip, altitude and temperature – to create a strategy for optimum shift performance. An ability to sense and compensate for all these variables allows this transmission to maintain consistent shift quality.

An additional gear allows shift points to be engineered to deliver an improved launch while delivering improved fuel economy. This is achieved by the increased ratio spread, a taller 2.87 final drive ratio and the ability of the transmission to shift at up to 6500rpm.

5L40 EC Cubing
The Electronic Torque Converter Clutch Control, or EC cubing, controls the amount of converter clutch slip – the difference between engine rpm and transmission input shaft rpm – in third, fourth and fifth gears. This increases the efficiency of the transmission during low torque applications. EC cubing can be activated at lower vehicle speeds, allowing fuel efficiency improvements to be delivered earlier.

Shift Stabilisation and Performance Algorithm Liftfoot
The transmission control system continuously evaluates driving conditions and driver inputs through the software functions Shift Stabilisation and Performance Algorithm Liftfoot (PAL).

Shift stabilisation reacts to differing vehicle loads and is active during constant speed driving. If the controller determines that optimum performance would be adversely affected by an upshift at that moment, the control system blocks this request. In real world scenarios, when driving uphill for instance, this algorithm reduces busy shifting or hunting.

PAL also responds to driver requests or driving style. To operate it requires greater than three quarters throttle pedal travel with a rapid release. This function is available while in Performance mode, and it considers the current driving style. Once the control system determines that the vehicle is being driven in a spirited manner, the current gear is held during deceleration. This assists with acceleration out of a corner, preventing unwanted upshifts, which results in the vehicle being in a more suitable gear during cornering and providing a more stable exit feel.

Active Select
The 5L40 Active Select feature is for drivers who wish to take more direct control, as it allows selection of the most appropriate gear for prevailing conditions. Safety features in this mode include maximum and minimum allowable engine speeds.

Four-speed auto transmission (4L60)
Upgrades to the 4L60 four-speed automatic transmission have improved shift feel and shift-to-shift variation through a new calibration that times shift events to ensure favourable use of available engine torque. It results in a more integrated powertrain feel between the ETC and transmission, resulting in better shift stabilisation and consistency.

This is made possible by new electrical architecture and the introduction of a more advanced transmission control module and software language.

The TCM software introduces more calibration variables – 8448 compared with 625 in the previous TCM – in the new language that allows it to process larger amounts of information, more quickly.

4L60 EC Cubing
Due to new TCM software, an upgraded 4L60 EC Cubing feature now allows for partial lock-up or controlled slip, improving the feel and fuel economy of an already efficient transmission

A new torque converter has been manufactured specifically for this application to better match the new torque characteristics of the engine. A combination of increased accuracy and a change to the coupling point of the converter allows matching of engine torque characteristics to vehicle response, providing improved engine-transmission integration, increased heat rejection and improved fuel economy.

Six-speed manual transmission (D173)
A new, premium application six-speed manual transmission replaces the current five-speed.

A lighter alloy remote shifter design and shorter shift throws improve shift feel and result in more direct-feeling changes. The short throw and light effort combine for quick shifting, balanced with Alloytec V6 engine characteristics.

The gate pattern has changed. Reverse is now next to first gear, the opposite side to the Holden V8 manual.

Clutch
Clutch diameter is 14mm larger at 254mm. Clutch pedal engagement is more progressive and has been developed specifically for the ratios and torque character of the engine. The clutch friction lining is now lead-free.

The clutch cover is self-adjusting, so that pedal effort does not increase as the clutch wears, ensuring a more consistent feel over the life of the component. Wear is further reduced by the use of an integrated concentric slave cylinder and release bearing.

Ratios
Ratio selection has been optimised by computer simulation, matched to the torque curves and tyre sizes. The ratio spread from first to sixth provides a more responsive first gear for better launch feel while allowing a sixth gear ratio of 0.75. This produces cruising revs of about 1800 rpm at 100kmh with resultant reductions in noise and vibration.

The new first gear ratio and the increase in clutch diameter enables towing of 1600kg – an increase of 30 per cent over ECOTEC V6 models.

Noise and Vibration
Noise and vibration improvements include increased casing stiffness and gear set tuning specifically for Holden use.

A new dual mass flywheel is tuned to engine characteristics and brings the benefits of reduced torque fluctuations in the transmission and lower driveline noise and vibration levels.