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                                                21st February 2009, 02:53 PM
                                        
                                
                                
                                        
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			 FL2 Technology FL2 Technology
 
			
				
					Cleaning up my computer and came across this article which I saved, probably back when I was looking at buying one. Anyway it explains some of the technology behind the FL2 and how it helps on road.
 
 Off-road it is a class-leader. Its capability starts with 210 mm
 (minimum) of ground clearance to overcome rocky, sandy, rutted or
 muddy terrain. This also helps Freelander 2 to wade through water
 up to 500 mm deep - better than most rivals. Approach and departure
 angles are also excellent.
 
 Full-Time Intelligent 4x4 System
 
 An innovative full-time intelligent 4x4 transmission is fundamental
 to delivering Freelander 2's class-leading breadth of capability.
 Its front-rear torque split varies continuously to suit dynamic
 conditions. Only a small amount of torque is fed to the rear wheels
 under normal conditions, such as on a straight tarmac road, but in
 tough off-road situations, almost all the engine torque can be fed
 to the rear wheels, if required. This is an ideal arrangement that
 always offers maximum grip in difficult conditions, yet minimises
 rear drive - and therefore rotational losses and, in turn, fuel
 consumption - when not required.
 
 "The torque balance adapts continuously," says chief programme
 engineer Andrew Foster. "So, for example, if you encounter mud or
 snow on the road, torque distribution between front and rear can be
 adjusted, to give you optimal traction and primary safety at all
 times."
 
 The intelligent 4x4 system has been developed in conjunction
 with Haldex, whose acclaimed centre-coupling technology
 continuously alters the front-rear torque split, normally through a
 hydraulically operated multi-plate wet clutch. However, Land Rover
 wanted an electronically controlled centre coupling - linking the
 propshaft to the rear differential - that could pre-engage at rest
 to reduce wheelspin from standing starts, engage quickly when
 traction loss was detected and disengage quickly without
 compromising stability control systems. The system also had to
 transmit the necessary torque to achieve Freelander 2's off-road
 traction demands.
 
 The result is used exclusively on Freelander 2, and proactively
 engages full-time 4x4 rapidly and completely. A new high-pressure
 pre-charge pump charges the hydraulic system as soon as the engine
 is started, allowing for full-time 4x4 from rest. It also reduces
 the time taken to achieve full torque once wheel-slip has been
 detected - within 15 degrees of wheel-slip rotation (compared with
 over 60 degrees of wheel-slip rotation with more conventional
 units).
 
 The Freelander 2's Haldex unit is designed to allow up to 1500
 Nm of torque transmission. An accumulator also speeds up the unit's
 response. Full torque transmission can be achieved in just 150
 milliseconds. In effect, the new Haldex coupling gives the
 proactive engagement benefits of full-time 4x4 and the efficiency
 and fuel economy of an on-demand system. Representing the best of
 both worlds, it is ideal for a compact 4x4 such as Freelander
 2.
 
 Terrain Response Enhances Go-Anywhere Ability
 
 Terrain Response is one of the core Land Rover technologies that
 gives the Freelander 2 its outstanding breadth of capability.
 Standard on all models, it adapts the responses of the vehicle's
 engine, gearbox, centre coupling and chassis systems to match the
 demands of the terrain. It optimises driveability and comfort, as
 well as maximising traction.
 
 On the Freelander 2, there are four Terrain Response settings
 which the driver can choose via a rotary control:
 
 
 General Driving - provides a broad span of ability suitable for
 most on-road driving and easier off-road conditions
 Grass/Gravel/Snow - for slippery conditions, on-road or
 off-road
 Mud and Ruts
 Sand
 
 "Each of the settings optimises Freelander 2's suite of
 electronic and mechanical controls to suit the chosen terrain,"
 says Andrew Foster. "It's like having an off-road expert to
 assist."
 
 Terrain Response also controls the following range of stability
 and traction aids:
 
 
 Dynamic Stability Control (DSC): is designed to help stop
 torque to a wheel after loss of traction, but in some off-road
 situations torque feed is still desirable, even when traction is
 being lost. Terrain Response automatically adjusts the DSC so that
 appropriate torque is maintained.
 Electronic Traction Control and Anti-lock Brakes: these slip
 and braking control systems are all adjusted and tuned by Terrain
 Response to offer optimum grip, braking power and safety on the
 chosen terrain.
 Hill Descent Control (HDC): the latest generation of the
 award-winning Land Rover technology that automatically restricts
 speed downhill, using the anti-lock brakes, and improves driver
 control on slippery descents. HDC is automatically engaged on
 appropriate Terrain Response programmes. Downhill speed rates vary
 according to which surface is selected.
 
 Terrain Response also changes the setting of the electronic
 centre coupling, to optimise 4x4 drive in tough conditions. It
 works continuously, and made its production debut in the Land Rover
 Discovery 3 in 2004.
 
 Large and Powerful Brakes
 
 The Freelander 2 has large vented discs front and rear, providing
 stopping power comparable to that of a good compact sports saloon.
 The large front discs - 316 mm on the petrol model, 300 mm on the
 diesel - are 'reverse vented', so they draw cool air into the disc
 over the central bell, which is then vented out from the rim of the
 disc. This approach improves thermal stability under severe
 braking. Rear brake discs are also substantial - 302 mm in
 diameter, for both diesel and petrol. The handbrake is a
 drum-in-disc device featuring two shoes per wheel. This achieves
 superior hill-hold performance compared with conventional disc-only
 systems.
 
 The electronic modulator at the heart of the stability control
 systems on Freelander 2 constantly monitors and, if necessary,
 adjusts both braking and engine traction to ensure the driver
 maintains control of each wheel. As well as reducing brake
 pressure, as in a conventional anti-lock (ABS) braking system, the
 modulator is designed to help generate positive hydraulic pressure
 to increase braking force in an emergency.
 
 In addition to the latest-generation four-channel anti-lock
 brakes, the modulator also controls Electronic Brakeforce
 Distribution (EBD), which balances the distribution of braking
 force between front and rear, Emergency Brake Assist (EBA), which
 boosts pedal pressure when full braking is required, and Corner
 Brake Control (CBC), which enhances rear-end stability when braking
 in corners. It also helps to control the Hill Descent Control,
 Electronic Traction Control and Dynamic Stability Control
 systems.
 
 Roll Stability Control
 
 Roll Stability Control is the most sophisticated roll-over
 prevention technology ever fitted to a Land Rover. Gyroscopic
 sensing allows this system - linked to the electronic modulator -
 to compare the rate of change of body roll angle with the steered
 course. If necessary, incremental brake force is applied at the
 outer wheels, widening the turn radius to help prevent the
 roll.
 
 Gradient Release Control
 
 Another innovation which makes its debut on Freelander 2 is Land
 Rover's patented Gradient Release Control system. Linked to the
 Hill Descent Control, this system ensures that, when releasing the
 brakes on extremely steep hills, brake-line pressure is released
 progressively, helping to maintain full driver control.
 
 Towing Capability
 
 Freelander 2's powerful engines, strong body and 4x4 transmission
 make it an ideal tow vehicle. Both petrol and diesel automatic
 models are able to tow a 2000 kg braked trailer - which is more
 than the vehicle's kerb weight - making them suitable for most
 single horseboxes, medium-sized caravans and many boats.
 
 
 
 
 
 
 
	
	
	
	
	
	
	
	
	
	
	
	
		
		
		
		
			
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