To reduce engine vibration when the engine is turned off, a new throttle closing strategy has been implemented, allowing fuel injection to be reduced more smoothly and controllably. At the same time, the generator is turned off to reduce the load on the engine.
Changes to the ECM software and new engine calibration make engine shutdown even smoother. In addition, optimized engine mounting and tuning reduce vibration during startup.
Components directly involved in starting and stopping the engine have been upgraded or replaced to accommodate the increased number of shutdowns and starts over the life of the vehicle. This section describes these upgraded and longer lasting components.
CAUTION: To ensure correct operation of the automatic Stop/Start system, only use recommended parts when replacing components, as some components from previous vehicle models are compatible with the TD4_e.
Starter
To increase reliability, taking into account the increased starting requirements, the starter has undergone the following modifications:
- The seals have been modernized.
- Wear-resistant contact material is used to reduce wear on the starter solenoid.
- The drive gear is made of a stronger grade of steel.
Flywheel ring gear
Due to increased starting requirements, the flywheel ring gear is made from stronger steel with a 25% higher carbon content, increasing the strength of the unit.
Double flywheel
As in previous diesel models, a dual flywheel is installed, which allows for smoother operation when starting, stopping and running the engine at low speeds.
To ensure even smoother operation with increased stopping and starting requirements, a new friction disc has been developed for the TD4_e dual flywheel. The new friction disc, which can withstand seven times the pressure of a conventional disc, is made from polyetheretherketone (PEEK).
PEEK is a semi-crystalline thermoplastic that is resistant to organic and aqueous environments. It has a high melting point, making it resistant to thermal degradation. It is also one of the few plastics that can work in ultra-high vacuum. It is commonly used in bearings, piston parts, and pumps.
Battery pack with glass microfiber absorbent partitions
Conventional batteries lose their ability to hold a charge over time as the internal lead plates deteriorate during normal use due to constant vibration and erosion. The rate of aging depends on many factors, including charge and discharge cycles. Therefore, the high power consumption of the Stop/Start system negatively affects the service life of this type of battery.
To counteract the extended discharge and charge cycles of the Stop/Start system, a high-performance battery was developed using glass microfiber absorbent baffle technology, which helps reduce battery aging due to intensive use. The battery owes its success to the absorbent baffles, which are thin sheets of glass microfiber between lead plates. The glass absorbent baffle also absorbs battery acid, allowing for more efficient use of can space.
The glass absorbent partition ensures the correct functioning of the electrolyte and also creates mechanical support for the lead plates, reducing vibration and, accordingly, aging. This technology significantly increases the effective number of charge/discharge cycles of the battery. The battery also has an extremely low internal resistance, which ensures a faster reaction between the acid and the plate material.
The technology of batteries with glass absorbent partitions has the following advantages:
- The battery remains completely sealed due to the absorption of the glass fibre plates.
- Under freezing conditions, the expanding liquid cannot damage the plates because they are sealed with fiberglass gaskets; accordingly, there is almost no displacement of the plates.
- Vibration and shock do not harm the battery.
- Since the electrolyte is retained in the partitions, there is no need for battery maintenance.
The battery capacity is 80 Ah, meaning it can theoretically deliver 80 amps of current for one hour. During a typical engine start, a very large current is drawn for a fraction of a second, so it has little effect on the overall charge of the battery. Restarting the engine requires approximately 0.001% of the full charge of a new battery.
If a new battery is installed in the vehicle, the BMS (battery monitoring system) unit requires recalibration to take into account the increased battery capacity; this is done using Land Rover approved diagnostic equipment. If diagnostic equipment is not available, the BMS will automatically recalibrate, but this may take up to 48 hours depending on vehicle usage. The Stop/Start system will not function correctly until the BMS has been recalibrated.
If the BMS unit is replaced, it will be calibrated automatically; for more information, see the Battery Monitoring System section below.
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