Anti-Stall and Traction Control Defender

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Originally Posted by Ruslan

Have read it twice and can't see anything about TDCi in the tread :eek:

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Nah... It's not mentioned in this thread but I'm fairly sure that's what CapeLandy is running.

M

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Originally Posted by Tusker

Can't follow this. Sliding is a matter of grip as much as it is speed.

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Yes... But depending on the conditions, you can get to a point where you're going too slow for the conditions and the car will start to slide even though you're on tick-over. (The tell tale sign for this is the car getting faster but the engine note staying the same.)

I hear what you're saying about crawler gearing & rock crawling but I suspect this isn't a large part of the Defender market....

M

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Originally Posted by camel_landy

Yes... But depending on the conditions, you can get to a point where you're going too slow for the conditions and the car will start to slide even though you're on tick-over. (The tell tale sign for this is the car getting faster but the engine note staying the same.)

I hear what you're saying about crawler gearing & rock crawling but I suspect this isn't a large part of the Defender market....

M

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You are seriously a LR driver trainer???

I would much prefer to have to accelerate slightly down a hill than try to brake, all the time fighting the engine.

There are plenty of tracks over here that are incredably steep, but have great traction, on these you need to go as slow as possble, there is never any question of losing traction.

On many tracks I will pull out the (mechanical) diesel engine stop on one of my landies, even though I have 49:1 gearing already - just to get it to slow down that extra bit without having to brake.

But many tracks are so steep that you will have to brake fairly hard as well.

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Originally Posted by ashtrans

good theory but I think you will find there isn't a sensor,

Dave

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care to explain how it knows that its in first gear or low range then...

is it one of those new star wars things and it just uses the force?

counts engine RPM vs speedo?

detects the overall velocity change of the vehicle from the ABS/TC sensors/inertia detection sensors and then using the glow plugs as a bimetalic couple thermal sensor calculates the combustion temp + pressure after cross referencing the desired engine torque requested VS the injector duty cycle and boost level has a calculated guess at the acceleration of the vehicle from the calculated engine torque output then solves out the maths to work out that its in 1/low so turns on the anti stall till the clutch hydraulics pressure sensor turns it all off before allowing the process to restart post gear change?

Im tipping there will be a simple switch/hall effect sensor on both the box and tcase in series with each other at some point that will tell the ECU to hit the antistall setting.

One thing I was not impressed is the salesman never explained in detail how the vehicle actually works or what it all does.
The manual is very basic and just gives an overview type explanation.
My motor I know is the Ford motor - I never new any TD5 dfender models came with TC/ABS or anti-stall.
Thanks for all the advise chaps.

[QUOTE=Blknight.aus;743202]

detects the overall velocity change of the vehicle from the ABS/TC sensors/inertia detection sensors and then using the glow plugs as a bimetalic couple thermal sensor calculates the combustion temp + pressure after cross referencing the desired engine torque requested VS the injector duty cycle and boost level has a calculated guess at the acceleration of the vehicle from the calculated engine torque output then solves out the maths to work out that its in 1/low so turns on the anti stall till the clutch hydraulics pressure sensor turns it all off before allowing the process to restart post gear change? QUOTE]

Ha! That brought a tear to my eye! Brillaint! I wouldn't put it past LR to use something that complicated.

All diesels have a form of anti stall yes even the antiquated 2.25 series diesel ( ditto all the way back to the first stationary single cylder open crank diesels) Its called a govenor.

if the engine RPM start to dip below the set speed then it opens up the injector duty cycle and feeds it more fuel. The electronic ones do it much faster and much better than the old mechanical ones to the tune of being technically capable of adjusting individual cylinders on the same turn of the crank (Ie if its fast after pot 1/4 has fired then 3 will get less fuel and if its slow after 3 has fired then 4 will get a touch more)

the ford 4 pot has it included as a feature but essentially its just a higher idle setting Ive only ever seen em test it on loose gravel/sand. Give me one for a couple of hours so I can load it up, bag down the tires and hook it up to something and I'll make it stall.

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Originally Posted by isuzurover

You are seriously a LR driver trainer???

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Exactly, I'm a trainer, not the guy that designs or builds the thing so I can't tell you chapter and verse why that decision was made. I've been talking about how it works so hopefully you'll read, understand and then use it to your advantage.

However, I do understand that the Defender is not designed specifically for you or me but has to accommodate a very broad spectrum of requirements & driving conditions.

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Originally Posted by isuzurover

I would much prefer to have to accelerate slightly down a hill than try to brake, all the time fighting the engine.

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Have you driven one of these yet? Once you understand what's going on (se previous posts), it's quite easy to work with. I haven't done the math but I think that even with the idle speed raised, it's still slower in 1st Lo than the TD5.

BTW - If you've ever been in the situation where you've started to slide coz the gearing is too low... You have to do more that 'accelerate slightly' and TBH most people in that situation would probably panic and slam on the brakes.

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Originally Posted by isuzurover

There are plenty of tracks over here that are incredably steep, but have great traction, on these you need to go as slow as possble, there is never any question of losing traction.

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If that's the type of track you only ever drive on, great. Personally, I've been on gentle slopes over in Oz that have had almost zero traction...

I suspect that you're sort of making the assumption that whoever drives these vehicles will only ever be driving in well worn ruts with good traction. In my experience, steep slopes with great traction is the minority. A damp, grassy slope is going to be one of the toughest challenges for any vehicle and when you factor in that farming is one of the biggest markets for the Defender, it all starts to make a little more sense...

M

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Originally Posted by Blknight.aus

Im tipping there will be a simple switch/hall effect sensor on both the box and tcase in series with each other at some point that will tell the ECU to hit the antistall setting.

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I'm with you on that one. There'll be a switch/sensor there somewhere.

M

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Originally Posted by camel_landy

Exactly, I'm a trainer, not the guy that designs or builds the thing so I can't tell you chapter and verse why that decision was made. I've been talking about how it works so hopefully you'll read, understand and then use it to your advantage.

However, I do understand that the Defender is not designed specifically for you or me but has to accommodate a very broad spectrum of requirements & driving conditions.



Have you driven one of these yet? Once you understand what's going on (se previous posts), it's quite easy to work with. I haven't done the math but I think that even with the idle speed raised, it's still slower in 1st Lo than the TD5.

BTW - If you've ever been in the situation where you've started to slide coz the gearing is too low... You have to do more that 'accelerate slightly' and TBH most people in that situation would probably panic and slam on the brakes.



If that's the type of track you only ever drive on, great. Personally, I've been on gentle slopes over in Oz that have had almost zero traction...

I suspect that you're sort of making the assumption that whoever drives these vehicles will only ever be driving in well worn ruts with good traction. In my experience, steep slopes with great traction is the minority. A damp, grassy slope is going to be one of the toughest challenges for any vehicle and when you factor in that farming is one of the biggest markets for the Defender, it all starts to make a little more sense...

M

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I haven't had a chance to drive one yet - the Perth LR dealer will just about hang up on you if you say you are interested in a defender.

The new defender has a 1st low of 62.9:1 - which is pretty impressive. 1000rpm at 62.9:1 is the same speed as 680rpm in an earlier model defender. Not sure what the idle rpm of a Tdi/Td5 is??? However, my 2.25D idles at 500rpm, and with 49:1 low range, has lower effective gearing than the new one...

However - I agree that for the average Nuffy defender owner, a device which stops them from slamming on the brakes and getting them into trouble (when going downhill) is a good idea. However the experienced user should be able to switch it off.