Pelyma
Member Since: 06 Jan 2005
Location: Patching, Sussex
Posts: 15496
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Can anyone tell me if this guy is correct about DSC on a FFRR compared to a D3, " but only in the description of DSC for the Range Rover HSE and Vogue does it explictly state that it acts "selectively to individual wheels". Most DSC systems act on the front and rear axles but do not balance between left and right and I suspect that the Disco has that type. While still providing some anti-snake protection, it is obviously not as good as one which can apply brakes independently to each of the four wheels. It would figure that the HSE and Vogue have a more sophisticated (and therefore more expensive) version." DS3 TDV6 HSE - Silver with Alpaca (old one) Gone
DS3 TDV6 HSE- Silver with Alpaca (new one) Gone
D4 HSE Lux - Montalcino Red Gone
Porsche Cayenne V8 Diesel S
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3rd Jan 2007 12:34 pm |
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simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
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I was under the impression that the DSC worked on all 4 wheels as well as engine retardation.
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3rd Jan 2007 12:51 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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DSC operates on any (or all ) wheels that are losing traction in addition to backing off the throttle, hence the four channel ABS on the D3
It is not 'per axle' -this would futher amplify any instability... sounds like he's talking out of his @rse
Quote:ABS
ABS controls the speed of all road wheels to ensure
optimum wheel slip when braking at the adhesion limit.
This prevents the wheels from locking, which helps to
retain effective steering control of the vehicle.
On the front axle, the brake pressure is modulated
separately for each wheel. On the rear axle, brake
pressure is modulated by select low. Select low applies
the same pressure to both rear brakes, with the pressure
level being determined by the wheel on the lower
friction surface. This maintains rear stability on split
friction surfaces.
CBC
CBC influences the brake pressures, below the DSC
and ABS thresholds, to counteract the yawing moment
produced when braking in a corner. CBC produces a
correction torque by limiting the brake pressure on one
side of the vehicle.
DSC
DSC uses the brakes and powertrain torque control to
help maintain the lateral stability of the vehicle. While
the ignition is on the DSC function is permanently
enabled unless selected off by the DSC switch. Even if
DSC is deselected, driving manoeuvres with extreme
yaw or lateral acceleration may trigger DSC activity to
assist vehicle stability.
DSC enhances driving safety in abrupt manoeuvres and
in understeer or oversteer situations which may occur
in a bend. The ABS module monitors the yaw rate and
lateral acceleration of the vehicle, and the steering input,
then selectively applies individual brakes and signals
for powertrain torque adjustments to reduce understeer
or oversteer.
In general: in an understeering situation, the inner
wheels are braked to counteract the yaw movement
towards the outer edge of the bend; in an oversteering
situation, the outer wheels are braked to prevent the rear
end of the vehicle from pushing towards the outer edge
of the bend.
The ABS module monitors the tracking stability of the
vehicle using inputs from the wheel speed sensors, the
steering angle sensor and the yaw rate and lateral
acceleration sensor. The tracking stability is compared
with stored target data and, whenever the tracking
stability deviates from the target data, the ABS module
intervenes by applying the appropriate brakes. On
vehicles with an automatic transmission, when the DSC
function is active, the ABS module also signals the
Transmission Control Module (TCM) to prevent gear
shifts. If necessary, the ABS module also signals:
• The ECM, to reduce engine torque.
• The transfer box control module, to adjust the
locking torque of the center differential.
• The rear differential control module, to adjust the
locking torque of the rear differential.
The DSC function overrides the differential locking
torque requests from the terrain response system.
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3rd Jan 2007 1:06 pm |
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DiscoDunc
Member Since: 08 May 2006
Location: Bristol
Posts: 16390
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Would this explain why on Saturday, when I was on very wet slippy grass uphill I wasnt going anywhere. I had TR set to grass, dsc on, low range auto and my foot planted to the floor, but the D3 didnt want to move
Q, do the diff locks still work if TR is OFF. The "locks" dont appear on the 4x4 display ?
Thanks Duncan
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If I'd known I was going to be so thirsty this morning I'd have drunk more beer last night.
FFRR Autobiography 4.4 SDV8 MY17
D4 HSE MY13 SOLD
FFRR 3.6 Vogue TDV8 SOLD
D4 HSE MY10 SOLD
D4 SE TECH MY15 SOLD
D4 XS MY12 SOLD
D4 HSE MY10 SOLD
D3 HSE MY06 - Re-Cycled Worldwide
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3rd Jan 2007 1:22 pm |
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simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
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The diff locks will work in 'Special Programs Off' mode.
They are optimised and have their state changed depending on the program - open, closed, half open/closed etc. Ready to react in a way LR deems to be the best way.
The grass may have made the traction on all four wheels very low and the TC would have tried to brake them to gain traction... ie confused it.
DSC would kick in if the D3 was sliding under power and would have reduced engine revs.
Thats my understanding so is probably wrongish.
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3rd Jan 2007 1:27 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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it may be more to do with the application of power, type of tyres, tyre pressures and gear selected, just 'planting it' generally doesn't induce traction
The centre and rear (if fitted) differentials will ultimately progressively lock without TR but the thresholds are much higher that with TR on. if all four wheels were spinning at more or less the same speed TC and difflock won't come on because the D3 doesn't know it's not moving, it needs to sense different wheel speeds for the system to kick in. Sometimes blipping the throttle or changing the steering angle can induce TC & differentials to lock
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3rd Jan 2007 1:30 pm |
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DiscoDunc
Member Since: 08 May 2006
Location: Bristol
Posts: 16390
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Thanks Simon,
that makes sense. I should have switched it all off. It was alittle embarrasing as I had just pulled a couple of D2's and a 110 out of some ruts, then totally failed on a grassy hill .
Ive got my LRE tomorrow, so lots of questions to ask. Ive done quite a bit of Offroading in the D3 but its almost like the "Terrain Response" needs a manual of its own to make the best of it Duncan
-----------------------------------------------------
If I'd known I was going to be so thirsty this morning I'd have drunk more beer last night.
FFRR Autobiography 4.4 SDV8 MY17
D4 HSE MY13 SOLD
FFRR 3.6 Vogue TDV8 SOLD
D4 HSE MY10 SOLD
D4 SE TECH MY15 SOLD
D4 XS MY12 SOLD
D4 HSE MY10 SOLD
D3 HSE MY06 - Re-Cycled Worldwide
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3rd Jan 2007 1:31 pm |
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DiscoDunc
Member Since: 08 May 2006
Location: Bristol
Posts: 16390
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Thanks 10Forcash,
"planting" the throttle was my last resort. I had tried "tickling" it ! etc. I then got impatient. I was on road tyres though
cheers Duncan
-----------------------------------------------------
If I'd known I was going to be so thirsty this morning I'd have drunk more beer last night.
FFRR Autobiography 4.4 SDV8 MY17
D4 HSE MY13 SOLD
FFRR 3.6 Vogue TDV8 SOLD
D4 HSE MY10 SOLD
D4 SE TECH MY15 SOLD
D4 XS MY12 SOLD
D4 HSE MY10 SOLD
D3 HSE MY06 - Re-Cycled Worldwide
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3rd Jan 2007 1:34 pm |
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simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
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Just keep in mind that wet grass is THE worst surface next to ice to drive on.
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3rd Jan 2007 2:03 pm |
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Pelyma
Member Since: 06 Jan 2005
Location: Patching, Sussex
Posts: 15496
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We've all ben there DD!! TFC do you think FFRR DSC is the same as D3/RRS? DS3 TDV6 HSE - Silver with Alpaca (old one) Gone
DS3 TDV6 HSE- Silver with Alpaca (new one) Gone
D4 HSE Lux - Montalcino Red Gone
Porsche Cayenne V8 Diesel S
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3rd Jan 2007 2:13 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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Can't see why it'd be anything else, a lot of the systems are common across the range now although the braking components will be different (Brembo?)
Why develop new systems when it's easier to adapt existing technology? Sounds to me like someone's trying to justify the price difference to themselves...
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3rd Jan 2007 2:20 pm |
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Duncster
Member Since: 25 Nov 2006
Location: Midlands
Posts: 755
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Off topic what does FFRR stand for??? 15 3.0 RRS HSE - Silver
05 2.7TDV6 S AUTO Silver - Retro-fitted Leather.
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3rd Jan 2007 2:28 pm |
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Pelyma
Member Since: 06 Jan 2005
Location: Patching, Sussex
Posts: 15496
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Full Fat Range Rover as opposed to RRS DS3 TDV6 HSE - Silver with Alpaca (old one) Gone
DS3 TDV6 HSE- Silver with Alpaca (new one) Gone
D4 HSE Lux - Montalcino Red Gone
Porsche Cayenne V8 Diesel S
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3rd Jan 2007 2:29 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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Full Fat Range Rover
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3rd Jan 2007 2:29 pm |
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Slimer
Site Moderator
Member Since: 06 Jan 2005
Location: Last Exit to Nowhere
Posts: 16295
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Full Fat Range Rover The End
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3rd Jan 2007 2:29 pm |
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