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C6REW
Member Since: 10 Mar 2007
Location: Devizes, Wiltshire
Posts: 576
  
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All of this still does not answer the fact that from re set the D3 goes when you put your foot down as witnessed by me with two cars. However after a period of time this changes and there appears to be lag.
With this in mind I am sure it is not turbo lag but more to do with the adaptive memory in the gearbox. I have never experienced this in any other car and certainly not in my BMW 530D.
Regards
Chris
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 10th May 2007 12:14 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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barryp wrote:I thought that the delay was due to turbo lag.
Could be a combination of turbo lag and fluid dynamics of the torque converter
barryp wrote:A couple of technical differences are that I understand that the X5 has a variable inlet nozzle on the turbo which changes its geometry dependant on the airflow allowing a quicker increase in turbo speed.
The Disco3 has a variable vane turbo also.
barryp wrote:Another issue is that as I understand it the D3 deisel is derived from the Jaguar engine however on the Jaguar they use two smaller turbos one on each exhaust bank. When modified for the D3 it uses one bigger turbo unit on the left side of the engine with the exhaust from the right bank travelling around behind the engine before entering the turbo unit. To me the physics of accelerating the single larger turbo must take more time than the two smaller units in the Jaguar application.
yes it does, the main reason for the single larger turbo (with variable vanes) is to produce low-down torque, the Jag engine (which is itself a derivative of a Peugeot designed unit) cannot match the D3 for torque. IIRC, the Jag has two different sized turbos for performance
barryp wrote:I have found with my D3 that easing the throttle open gently initially then a smooth and progreesive opening appears to give a more reliable and rapid takeoff. If I open the throttle wide on mine it definately hesitates untill the turbo boost pressure builds.
all diesel engines work better this way, again, there is some 'lag' induced due to fluid dynamics in the auto box & torque converter. a simple test to confirm that the fluid solenoids are operating corectly within the auto box is to decent a fairly steep hill (on or off road) with TR set to 'Mud & Ruts' but with HDC off and transmission command shift 1st gear selected, with no braking or throttle input, engine braking should be evident. Also check that when in command shift, the gear indicator numbers increment without delay when shifting up & down the gears. For immediate take-off, try using left foot braking whilst gently applying throttle, this will pre-lock the torque converter and give you instant action 
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| 10th May 2007 3:26 pm |
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Slimer
Site Moderator
Member Since: 06 Jan 2005
Location: Last Exit to Nowhere
Posts: 16295
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10forcash wrote:barryp wrote:I have found with my D3 that easing the throttle open gently initially then a smooth and progreesive opening appears to give a more reliable and rapid takeoff. If I open the throttle wide on mine it definately hesitates untill the turbo boost pressure builds.
all diesel engines work better this way, again
Which leads me to wonder (again) if a lot of the complaints about lag are from petrol heads that aren't used to the differences of driving a diesel  Instant foot to the floor stuff is probably always going to lead to hesitation on a diesel, lighty does it and learn to drive using all that torque instead The End
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| 10th May 2007 3:35 pm |
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Gareth
Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26701
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Quote:try using left foot braking whilst gently applying throttle, this will pre-lock the torque converter and give you instant action
TFC, this produces an "Engine system fault" on mine, which goes away when I release the brake. Its the only time I see a fault these days, but its very repeatable.
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| 10th May 2007 4:41 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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There's a software update to get rid of that
LTB00025
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| 10th May 2007 5:00 pm |
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DirtyDisco
Member Since: 21 Oct 2006
Location: County Durham
Posts: 76
 
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Would I be correct in assuming that the D3 owners on this site with a manual box have none of the problems? If I i have the car out of gear (Park or Neutral) any pressure on the throttle gives an instant reaction. I therefore assume that the delay is not related to the engine itself but the electronics giving it the throttle inputs. All this leads me to ask does a remap from our sponsors solve the problem as has been suggested? For me I would buy on the strength of this benefit. If it provided a little more economy too then it would be self funding. Serial Depreciation Victim
07 D3 TDV6 HSE. Side Steps. Privacy. TV. Stornoway + Alpaca.
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| 10th May 2007 10:25 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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Throttle response will be improved in P or N as there is no engine load....
a remap will minimise turbo lag but won't help with transmission losses or torque converter lock-up
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| 10th May 2007 10:38 pm |
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DirtyDisco
Member Since: 21 Oct 2006
Location: County Durham
Posts: 76
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I agree, with no load the revs should increase rapidly as with any car. In drive the throttle response should be just as quick until the load is 'felt' by the engine i.e. the drive starts to load up through the box, but nothing happens, no noise, no increase in revs, no engine pitch change. I am convinced that there is a gremlin. Do I just have to accept it? Serial Depreciation Victim
07 D3 TDV6 HSE. Side Steps. Privacy. TV. Stornoway + Alpaca.
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| 10th May 2007 10:55 pm |
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Simong
Member Since: 26 Feb 2006
Location: Spectacular Yorkshire
Posts: 94
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Quote:Which leads me to wonder (again) if a lot of the complaints about lag are from petrol heads that aren't used to the differences of driving a diesel Instant foot to the floor stuff is probably always going to lead to hesitation on a diesel, lighty does it and learn to drive using all that torque instead
Well I am a petrolhead, but I've never experienced the lack of throttle response that I am getting with the D3. And I've driven plenty of diesels in the past without this hesitation.
So what are the differences you refer to?
I don't think it's got anything to do with the fact it's a diesel engine and from my conversations with LR neither do they, I just think it's poor mapping- after all people are stating that the 07 cars are better along with the aftermarket maps.
Unfortunately, nobody seems to have a definitive answer, or have I missed something?
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| 10th May 2007 10:55 pm |
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Jads777
Member Since: 03 Sep 2005
Location: Channel Islands
Posts: 697
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10forcash wrote: For immediate take-off, try using left foot braking whilst gently applying throttle, this will pre-lock the torque converter and give you instant action
What are the implications of this regarding wear on components? I have tried this occasionally when trying to leave some smartarse behind at the lights, but should we reserve this for infrequent use?
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| 10th May 2007 11:00 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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DirtyDisco, The torque converter will start absorbing engine torque before it can properly develop, have you tried a comparison drive in a similar milage vehicle? this will prove or disprove your gremlins...
Simong, The D3 isn't a racing machine - it's 2.7 tonnes of Landrover... The basic changes in the 07MY are to the engine mapping, fuel rail pressure, EGR system and (due to the increased pressure) fuel injectors, as far as i'm aware, the transmission control is unchanged. Without being patronising, I suppose it depends upon your perception of what you expect of it, and TBH, once the D3 gets going, it's very easy to forget how big & heavy it is. I've driven several D3's both auto and manual transmission and there are differences, how noticable they are depends upon how you drive them and how much you focus on the D3's 'individuality'. In some cases, the adaptiveness of the engine & gearbox may be seen as a weakness, not a strength
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| 10th May 2007 11:07 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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Jads777, no premature wear or stress, the gearbox fluid may heat up slightly more but this should have no more impact than sitting in traffic with your foot on the brake and the gear selector in drive
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| 10th May 2007 11:09 pm |
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Jads777
Member Since: 03 Sep 2005
Location: Channel Islands
Posts: 697
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10forcash wrote:Jads777, no premature wear or stress, the gearbox fluid may heat up slightly more but this should have no more impact than sitting in traffic with your foot on the brake and the gear selector in drive
That is good news. Wait until I see that flash git in the Porsche tomorrow morning. 
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| 10th May 2007 11:19 pm |
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Simong
Member Since: 26 Feb 2006
Location: Spectacular Yorkshire
Posts: 94
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TFC- Fully appreciate the 2.7 tonnes scenario, however I don't believe that when you put your foot down you have to wait for 3 secs before anything happens and I do mean before anything happens at all.
Once it's moving, then it moves very well for a big lump. My issue is that when I press the pedal nothing at all happens for 3 seconds, then whoosh.
LR have admitted that there is a delay, they just won't tell me what is acceptable to them. That's all I'm after finding out.
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| 10th May 2007 11:31 pm |
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bkehoe
Member Since: 25 Feb 2006
Location: Wexford
Posts: 1481
 
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I think this delay is normal - mine certainly has it, but 99.9% of the time I don't notice it any more and have adapted my driving style to work around it. It was far worse before TC with the original 2005 software (LR released newer ECU maps to help reduce the lag in early 2006). I could easily recreate a situation where driving along I could then floor the accelerator and count to 3 or 4 before there was any reaction.
However, I agree, sometimes, usually at the worst possible time, it'll catch you out. Most recent was this week, edging out of a fairly blind junction when I caught sight of a van rapidly approaching and floored it - the result was the D3 creeping slowly out in front of the van untill suddenly a massive surge of power pushed me out of the way with only seconds to spare. Last time was over 6 months ago and involved a rather larger artic lorry in the same kind of a situation. So yes, it's going from no to full throttle suddenly that seems to result in this big delay.
Maybe also related to the kickdown being triggered upon a sudden full press of the pedal? As in both those situations with the threat of impending doom I would be pretty sure I'd have pressed the pedal enough to trigger a kickdown in the autobox, whereas in normal situations I'd never press the pedal that much. IE - 05 D3 TDV6 HSE - Zambezi Silver
SA - 07 VW Golf TDI - White - Sold!
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| 10th May 2007 11:50 pm |
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