Is the Freelander 2 really a full-time 4x4? My understanding is that it starts 4x4 and then goes to front-wheel drive if there is enough grip. Also, does different Terrain Response modes make it a more full-time 4x4? And finally, what are the front-to-rear-drive ratios on the different modes? 2007 Freelander 2 HSE i6
stornoway grey
black leather

I seem to recall from my LRE day, that a minimum of 15% of power is always to the back, and this changes with the terrain response setting

Just read on the WhatCar review of the FL2, that at least 3% of power is sent to the back. (this seems to make more sense!)

boiledgnat wrote:

Just read on the WhatCar review of the FL2, that at least 3% of power is sent to the back. (this seems to make more sense!)

I've just asked the technical guys at Haldex to answer all of our questions with a brief explanation of how the system works at start up and during driving etc. so we'll see what they come back with.

Gambba.

3% minimum at the back was also my understanding, think I got that from the LRE guys.

Hats off to Haldex and a guy by the name of Mats (Who drives an LR2 and was involved in the project) for coming back so quickly on my question.

My question:

Quote:

I was looking for a brief overview of exactly how the Land Rover Freelander 2 (LR2) Haldex system operates on the vehicle i.e. start-up process, standard front rear power split etc.. Some magazines and information say that the standard (lowest) amount of power sent to the rear wheels is 3% or 5% depending on source of information. I was hoping for some information that I could share with fellow car enthusiasts on a Freelander 2 forum www.freel2.com.

Quote:

The Haldex system use several CAN (controller area network) signals from the vehicle to operate such as accelerator, brake pedal, wheel speed, engine speed, engine torque, gear position, lateral acceleration, yaw rate etc. The signals are read every 20ms and processed in the Haldex ecu and from that the ecu decide what the proper torque transfer from the front to rear should be.

When the vehicle is powered up the haldex system will activate a feeder pump and close the valves to build up a base pressure for instant traction. The system will then wait for the signal from the engine speed to show a value higher then 400 rpm before it is ready to transfer any torque, this to allow you to perform two wheel tows etc. But as soon as the signals are there the system will be ready to give an immediate 500 Nm torque transfer until the system tells it otherwise (that is higher or lower torque).

It is unfortunately impossible to say what the standard torque level is since this is completely dependant on what surface are you driving on, what speed, what angle of your steering wheel etc, the computer in the haldex will take all this in consideration each time and from that select the torque level.

What the magazines are talking about is the dragtorque, the torque that will always be there due to the energy used to turn the coupling, differential etc and that will be around 3-5 Nm.

Mats of Haldex has a presentation that he made for the system used on the LR2 that will better describe the systm, but needs to slim it down a bit and then will arrange for me to download it from their FTP site, which then I guess I can upload it into the gallery? or ask Martin to sort something out for it.

to Haldex (and Mats).

Well done Gambba, and Mats of course.
Thanks for the beautiful details and scientific description!
I wish I could get such details about some other FL2 systems, as the Auto box and the 'spooky' a/c humidity sensor (which I have no clue how or when it works). Actually trusting my FL2 I never put the A/c on recycling the air, expecting that when a big truck spits 500gr/km of CO2 and particles on me, the polution/humidity sensor does it for me automatically. I then visit my clients with an inch of carbon on my face.

An excellent bit of research. Looking forward to seeing the additional stuff when it comes through.