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Thread: Defender "slow race" - TDCi vs TDi

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    Defender "slow race" - TDCi vs TDi

    Gang - would be VERY interested to test empirically whether the TDCi is faster or slower than TDi at idle in low first and low reverse.

    Has anyone got both vehicles? Mind doing a test? Of course having similar size tyres and no gearing mods would be a prerequisite.

    Reason for asking:
    - TDCi's have this feature that should be transparent to vehicle operator and it's called "idle jack"
    - idle jack in TDCi simply raises idle speed from 800rpm to 1100rpm but only in low first and low reverse (and when clutch pedal is fully up)
    - the reasoning from LR for this feature is that apparently the TDCi gearing in low 1&R is lower than older models, apparently deemed to low for safely driving steep descents, and so they raise engine idle to compensate.

    Some TDCi owners feel the vehicle speed in low 1&R is too high, higher than older models, and I'd love to test this empirically.

    Can you help?
    Neil
    (Really shouldn't be a...) Grumpy old fart!
    MY2013 2.2l TDCi Dual Cab Ute
    Nulla tenaci invia est via

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    I've got both,the TDCi is slower.Mine only rev's up when anti stall kicks in,I've found it's better to let the clutch right out and let anti stall do it's thing when pulling a heavy load off idle or driving over a rough piece of ground.The Tdi stalls. Pat

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    I ran the numbers, as Pat says the TDCi (dotted line) still travels a touch slower even at 1100rpm than the TDi (solid line) does at 800-850rpm. We're talking a fraction of a km/h though (TDCi at 2.65 km/h, TDi at 3.25 km/h - again, purely mathematically [on 235/85r16s]).

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    Quote Originally Posted by Dervish View Post


    I ran the numbers, as Pat says the TDCi (dotted line) still travels a touch slower even at 1100rpm than the TDi (solid line) does at 800-850rpm. We're talking a fraction of a km/h though (TDCi at 2.65 km/h, TDi at 3.25 km/h - again, purely mathematically [on 235/85r16s]).
    Hows about the numbers for low range reverse gear? What does that look like?
    Neil
    (Really shouldn't be a...) Grumpy old fart!
    MY2013 2.2l TDCi Dual Cab Ute
    Nulla tenaci invia est via

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    Quote Originally Posted by PAT303 View Post
    I've got both,the TDCi is slower.Mine only rev's up when anti stall kicks in,I've found it's better to let the clutch right out and let anti stall do it's thing when pulling a heavy load off idle or driving over a rough piece of ground.The Tdi stalls. Pat
    Hey Pat - are you saying the TDCi moves slower than the TDi in low first and also in low reverse?
    Neil
    (Really shouldn't be a...) Grumpy old fart!
    MY2013 2.2l TDCi Dual Cab Ute
    Nulla tenaci invia est via

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    TDCi reverses at 2.95 km/h (1100rpm), TDi (R380) at 3.2 km/h (850rpm).

  7. #7
    MrLandy Guest
    Quote Originally Posted by Dervish View Post
    TDCi reverses at 2.95 km/h (1100rpm), TDi (R380) at 3.2 km/h (850rpm).
    Is that on the flat? ...Are you able to factor in a steep downhill descent, so that engine braking, or lack thereof, in low reverse comes into play, rather than just acceleration speed? IME the higher rpm is the issue reversing down hill in low in the Tdci compared to the 300 Tdi. .

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    Quote Originally Posted by MrLandy View Post
    Is that on the flat? ...Are you able to factor in a steep downhill descent, so that engine braking, or lack thereof, in low reverse comes into play, rather than just acceleration speed? IME the higher rpm is the issue reversing down hill in low in the Tdci compared to the 300 Tdi. .
    There is no shortage of compression braking available with the TDCi 2.2 engine in my experience. Where there is good traction - mine reverses slowly down the steepest inclines and doesn't start to run away at all. (On a slippy steep slope - have to use some throttle at times to keep wheels turning at a rate that approximates vehicle speed to avoid uncontrolled sliding)

    I wonder if the TDCi behavior that has you worried is that other behavior I wrote up in the other thread: the one about how the TDCi takes its time to drop revs to back to idle (any gear, low or high range, on or off road).
    ( Idle-Jack Dangerous in low range reverse Puma )

    This does give the impression of a lack of compression braking available in the TDCi. But what is really happening is the electrickery just takes its merry time to drop right back to idle revs. (And as described in the other thread - this is a pure GOLD asset on slippery descents in any gear)
    Neil
    (Really shouldn't be a...) Grumpy old fart!
    MY2013 2.2l TDCi Dual Cab Ute
    Nulla tenaci invia est via

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    Quote Originally Posted by Dervish View Post
    TDCi reverses at 2.95 km/h (1100rpm), TDi (R380) at 3.2 km/h (850rpm).
    Mines much slower,mine doesn't do the 1100 rpm bit until it loads up and then anti stall takes over. It trundles along until it hits a rut,the rev's kick up as it goes over and then settles down again,the Tdi labours and then goes over or stalls.I find the TDCi to be excellent when towing,feet off all the peddles and just steer,the low rev's and deep gearing are light years ahead of the Jap crap. Pat

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    Quote Originally Posted by PAT303 View Post
    Mines much slower,mine doesn't do the 1100 rpm bit until it loads up and then anti stall takes over. It trundles along until it hits a rut,the rev's kick up as it goes over and then settles down again,the Tdi labours and then goes over or stalls.I find the TDCi to be excellent when towing,feet off all the peddles and just steer,the low rev's and deep gearing are light years ahead of the Jap crap. Pat
    That's interesting, Pat. In low first/reverse, mine ramps up to 1100 rpm a few seconds after its feet off pedals - Every time. Then it behaves as you describe with anti-stall doing its thing to keep revs at 1100 (I don't think it ever overruns 1100).

    (Of course in other gears its ~800rpm, not 1100)

    You have a 2.4 TDCi, right? Mine is a 2.2. I wonder if LR made some changes along the way...
    Neil
    (Really shouldn't be a...) Grumpy old fart!
    MY2013 2.2l TDCi Dual Cab Ute
    Nulla tenaci invia est via

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