Device and technical description Turbocharger (Discovery 3)

Item name	Spare part catalog number	Description
1	-	Oil supply pipe
2	-	Left exhaust manifold
3	-	Drive motor
4	-	Drive lever
5	-	Oil drain pipe
6	-	Turbocharger

In a turbocharger with a variable nozzle device, the amount of exhaust gas passing through the turbine is regulated depending on the operating conditions. The turbocharger is installed on the left exhaust manifold of the TdV6 engine. This leads to an increase in the power realized on the turbine and compressor, especially in the low crankshaft speed range, and to an increase in boost pressure. As the engine speed increases, the device blades gradually move to an open position, maintaining a balance of the power realized on the wheel in accordance with the requirements of the speed and load modes. Compared with a traditional turbocharger, which uses wastegates, a turbocharger with a variable nozzle device ensures higher engine efficiency due to better use of the energy of the exhaust gases.

Advantages:

• High engine torque at high and low rpm
• Continuous optimal control at all engine speeds
• No need for a boost pressure regulator, better use of exhaust gas energy, lower back pressure with the same compressor operation
• Low thermal and mechanical load improves engine energy performance
• Reducing exhaust toxicity
• Optimization of specific fuel consumption throughout the entire engine operating speed range

The turbochargers are of the same design as those in the Freelander's Td4 engine. However, instead of a vacuum diaphragm, the electronic control of the blades is performed by a stepper motor.



The drive shaft of the nozzle unit is rotated by a DC motor. The drive shaft is connected to the blades by a drive lever. The movement of the lever causes the blades of the unit to move. The rotation of the drive shaft generates a feedback signal that carries information about the angular position of the blades. This information is transmitted to the engine control module (ECM).

The control unit contains a temperature sensor that moves the stepper motor to a safe position. (completely open) when the maximum permissible temperature is exceeded. The engine control unit monitors stepper motor faults and generates fault codes.

Item name	Spare part catalog number	Description
A	-	Closed (high speed)
B	-	Open (low speed), default position
1	-	Turbine
2	-	Blades of the device
3		Drive lever

At low crankshaft speeds, the blades are positioned such that the relatively slow exhaust gas flow accelerates and enters the turbine wheel blades at the greatest angle. Accordingly, a large torque is generated on the turbine wheel, and the wheel develops a high rotation speed.

(The article was copied from the website: LRMAN.RU)



At high crankshaft speed, the blades gradually open and a large amount of exhaust gas slows down and is directed toward the turbine wheel axis.

The torque on the turbine wheel is artificially reduced. In this way, the speed of the turbine wheel and thus the intake air flow are adjusted in accordance with the engine crankshaft speed. The boost pressure remains approximately constant over the entire engine speed range.

Operating parameters are controlled by the ECM using data from transmission sensors and driver commands. For more information, refer to Electronic Engine Controls (303-14C Electronic Engine Controls - 2.7L Diesel)

The turbocharger provides fail-safe operation. If a control failure occurs, the device's blades default to a fully open position to reduce boost to a minimum.