What went wrong....

[Phoenix12]

Out at Stockton beach on Sunday arvo and having an awesome time until I tried a few steeper dunes. (2011 Puma)
Hopped into low w/ difflock and then gunned it....didnt make it the first time, but made it the second !
Then tried a steeper section, but no go....everything else was making it up, just not me.....Looked like a bit of a tosser (or so I felt anyway !)

It just seemed like I was bogging down, couldnt get a run up to keep the revs up, and found I was dying in the ass big time. Then started to smell that lovely "I am working this vehicle to hard" smell. So,........tail between the legs.....I am outta there, shaking my head in disbelief at how all the jappys could do me in........

Stock standard tyres (A/T) run at around 14 -16 psi (dependant on what gauge I read it with !!)

Clutch dying ? (smell ?)

What was I doing wrong ?

I cant have this happen again, fellow deefers you must help !!!!!!!

[ugu80]

Stock standard tyres (A/T) run at around 14 -16 psi (dependant on what gauge I read it with !!)


Try 8-10 psi.

[87County]

if the mates you are doing it with are used to doing it, and if you haven't had much experience at it ....

lower pressures may help but there is a downside....

not very helpful I know, but some training in technique might assist - you'd reckon they would have helped with advice :o

also - did they have bigger tyres ?

[Allan]

What gear low range did you use. I've found most times I have only needed high range on most dunes, the first two or three ratio's in low range are not really the best choice for dune climbing IMO.

Allan

[Hoges]

when traversing sand, the idea is to try and maintain momentum and "float" over the top in the highest gear practicable, not dig yourself in.. hence the low tyre pressure to maximise footprint and spread the "point load" ...it is possible that you may have been in too lower gear so instead of floating you started to dig in with too much torque. Were you in high or low range? Did you try it for example in a low (2nd) gear in high range?

It's a different technique for example in mud and snow where, with slightly thinner tyres and aggressive tread you maintain the tyre pressure with a view to increasing the pressure of the tyres' footprint and force surface compaction to get a grip...sand will not let you do this...

Regarding tyre pressure: let the tyres down just a tad more, but too much as you might damage the side walls and roll one off the rim.

As 87County says... technique is important and with practice you start to get a "feel" for the conditions... Maybe with your set up for those particular conditions, the laws of physics were not on your side.. :(

Choose your battles carefully :eek::twisted:

[Loubrey]

We had a long thread/discussion on the 2011 Puma's Traction Control recently where I described the exact same thing.

Decent run up, nice low pressures, but the moment the wheels "kick" on the way up the dune the TC engages to stop the spin, systematically ending up doing it to all 4 wheels and the car stalling. This is not an "urban legend" regarding Pumas, but a unique occurence on steep dunes. As I also own one, I'm allowed to mention it! ;)

Like the guys mentioned:

Tires as low as you dare.
Higher gear for more speed/momentum
If you really, really want do race up dunes - remove the ABS fuse (but it will record an error on the ECU)

The main thing is that your car still outclasses them in every other environment and if you want to race around dunes, get a VW Baja Bug...

[Hoges]

or a camel:eek::p

[PAT303]

I've never found low range any good in sand,stockton has the softest sand I've ever driven on and needs low tyre pressure and high range with lots of rev's. Pat

[lambrover]

Laubry is correct it's the traction control kicking in mate, the smell is not clutch it's brake pads. Not sure if there is a mod for it ie some one has a switch and harness made to turn the TC off. Removing the fuse will disable the TC, remember to refit once off the beach. You could look into wiring up your own switch to disable.

[Allan]

We had a long thread/discussion on the 2011 Puma's Traction Control recently where I described the exact same thing.

Decent run up, nice low pressures, but the moment the wheels "kick" on the way up the dune the TC engages to stop the spin, systematically ending up doing it to all 4 wheels and the car stalling. This is not an "urban legend" regarding Pumas, but a unique occurence on steep dunes. As I also own one, I'm allowed to mention it! ;)

Like the guys mentioned:

Tires as low as you dare.
Higher gear for more speed/momentum
If you really, really want do race up dunes - remove the ABS fuse (but it will record an error on the ECU)

The main thing is that your car still outclasses them in every other environment and if you want to race around dunes, get a VW Baja Bug...

In regards to the code on the e.c.u. Does it record it as a single fault or multiple i.e. switch of the traction control ten times ten recorded faults or does one override the other.

Allan

[KarlB]

I've never had an issue with traction control in my 2010 D90 in sand and doubt that it is the issue. It is all most certainly a gearing and momentum issue. I have find times in very soft sand that if I backed off the accelerator I actually surged forward as the wheels stop spinning. Try starting in third or fourth low and tackle the dunes in fifth or sixth low. If still a problem then try high range. What you are trying to achieve is good momentum with low engine revs while still having full directional control of your vehicle. If you can feel you are going down don't plant your foot, that will dig you deeper. I normally run at 18 psi in sand on standard tyres.

Cheers
KarlB
:)

[Blknight.aus]

This thread is the very reason I maintain that all the acronym add ins should only ever be relied upon as a warning that you are approaching the limits of your vehicles native ability......

If you got there by raping your mechanicals via the electronics,,, what happens when the electronics go west or you burn out the brake pads....

Ive been on trips where badly driven and setup electronic vehicles have gotten to the end of some sections with smoke coming off the brakes, not steam, smoke.



Decent run up, nice low pressures, but the moment the wheels "kick" on the way up the dune the TC engages to stop the spin, systematically ending up doing it to all 4 wheels and the car stalling. This is not an "urban legend" regarding Pumas, but a unique occurence on steep dunes. As I also own one, I'm allowed to mention it! ;)


Im sorry, allegedly this can NOT happen, the puma is supposed to have stall control...

[newhue]

Anti stall only exist in low 1.

Nugget had a similar problem. Traction control brakes the vehicle looking for traction which hinders the cars momentum on steep slippery slopes like sand or clay. It has to be steep however, and no aids may still achieve the same result.

[scarry]

What you have to do is go back when no one else is there& have a go in high range,try a few different things ,i also doubt TC is the issue.

My son has never had an issue with his in real soft sand,and he is often with his mates that have jap things with diff locks.They actually cannot believe how good the deefer is stock.

I did a lot of sand driving in the D2,TC was never an issue.In fact against a mate with a LC TD trayback,it would beat it easily up any dune.

Speed & momentum is the go

Good luck

[lambrover]

I remember reading threads about the D2's TC making it hard going in the sand, the fix was to remove the fuse.

What's changed

[slug_burner]

If you crawl up at walking speed and have traction on some wheels TC is your friend. If you are going for a bit of the old slipper (right foot) TC will be your enemy unless you have enough grip on the majority of wheels to retain traction and forward momentum.

Remember that TC is the intermittent application of the brakes, on sand you end up with all wheels with an intermittent application (i.e., reduced duty cycle) of the brakes. This kills your momentum.

[MR LR]

We had a similar problem with our D2, before fitting the CDL lever, the front brakes would constantly, rides and hence burn and kill momentum, with the CDL locked there is little if no problem at all, maybe a front locker is needed if you want to go real extreme (or rear aswell).

Cheers
Will

[KarlB]

Can somebody explain how ETC kills momentum in a sand driving situation?

[camel_landy]

Anti stall only exist in low 1.

Wrong... That is the 'Idle Jack'.

M

[101RRS]

Can somebody explain how ETC kills momentum in a sand driving situation?

There is a complete thread on this http://www.aulro.com/afvb/90-110-130-defender-county/148643-traction-control.html

Issue raised a few times but not resolved - as TC is working on the wheel that has no traction, I also would like to know how momentum is destroyed.

Garry

[camel_landy]

To cover the initial question, it sounds as though you have selected too low a gear.

Wheel spin is caused by torque... The lower the gear, the greater the torque.

When climbing, you need to select a higher gear, not lower. That will increase momentum as well as reduce the amount of torque at the wheels.

If you're in soft sand, dropping the tyre pressures will help too.

Anti-Stall
Anti-Stall is available in all gears... It is actually more a feature of ANY engine with EFi, not just Land Rover engines. The engine ECU on any car will monitor the engine speed, if the engine speed drops, it adjusts to maintain the steady engine speed. Hence why TD5 has 'anti-stall' too.

All that Land Rover do, is take this effect, get it to operate within different parameters and call it a 'feature'. ;)

Idle Jack
1st gear, lo-range... When the car is moving, the idle speed is raised slightly to prevent the car from providing too much engine brakeing and reducing the chances of the car sliding on steep descents.

M

[slug_burner]

Can somebody explain how ETC kills momentum in a sand driving situation?

In this case for simplicity we will say the centre diff lock is engaged that way you can consider each axle as operating without transferring torque to the other axle.

A break of traction results in the application of the brakes to the spinning wheel, when the brake is applied to the spinning wheel that wheel stops spinning forcing the wheel on the other end of the axle to break traction if it is not already spinning. The cycle repeats over and over again. Each time the brakes are released if there is enough traction for the torque applied then the vehicle will move forward but in the case of sand it is likely to have insufficient traction and the wheel spin will just help to dig you in further.

In order to maintain your momentum you must deliver enough power to overcome the friction of the sand, if you don't get it right you slow down and stay on top of the sand without breaking traction or you break traction and start digging in. Even the short application of the brakes as is done by the TC system (over and over again) converts energy out of the system into heat in the brake pads/rotors. Every time the brakes are released the sudden rotation of the wheel breaks traction and starts digging in.

[101RRS]

A break of traction results in the application of the brakes to the spinning wheel, when the brake is applied to the spinning wheel that wheel stops spinning forcing the wheel on the other end of the axle to break traction if it is not already spinning.

No it doesn't, the wheel that has drive transferred to it will normally be stationary or turning much slower than the spinning wheel and when it gets drive it bites and pulls the vehicle. If the it looses traction (no drive) and it starts to spin faster than the other wheel, drive is transferred to the other wheel and so on.

At no stage is any wheel that has traction braked - only those wheels, that not only have no traction but are spinning faster than another wheel with traction are braked.

Cheers

Garry

[newhue]

To cover the initial question, it sounds as though you have selected too low a gear.

Wheel spin is caused by torque... The lower the gear, the greater the torque.

When climbing, you need to select a higher gear, not lower. That will increase momentum as well as reduce the amount of torque at the wheels.

If you're in soft sand, dropping the tyre pressures will help too.

Anti-Stall
Anti-Stall is available in all gears... It is actually more a feature of ANY engine with EFi, not just Land Rover engines. The engine ECU on any car will monitor the engine speed, if the engine speed drops, it adjusts to maintain the steady engine speed. Hence why TD5 has 'anti-stall' too.

All that Land Rover do, is take this effect, get it to operate within different parameters and call it a 'feature'. ;)

Idle Jack
1st gear, lo-range... When the car is moving, the idle speed is raised slightly to prevent the car from providing too much engine brakeing and reducing the chances of the car sliding on steep descents.

M

Idle Jack, never head of it. That is not what Land Rover called it. My car will stall in all gears but low 1. In low 1 it may brake traction but will keep spinning regardless of what it's up against. I'd imagine for just about everyone, common sense would prevail and the clutch disengaged before any drive line components could be damaged. But it acts like a hand throttle.

I have head what you are calling Anti Stall is required by modern motors to maintain anti pollution requirements. Not sure how that helps when I change gears the motor runs on for a half second, but I don't make the rules.

[Allan]

T.c fault code question:- In regards to the code on the e.c.u. Does it record it as a single fault or multiple i.e. switch of the traction control ten times ten recorded faults or does one override the other?

Allan

[Loubrey]

The car ONLY does it on steep dunes - not in any other sand driving condition as has been said on a number of times now...

As Slug Burner explained - on a steep dune the TC functions correctly in stopping the wheel with least traction, but if there is no traction for any of the 4 wheels what would you expect to happen...? The TC does at that point apply brakes to all 4 wheels thus slowing the car and eventually stalling it pretty violently. This is not just a theory, but something I've seen on many occations on a number of Pumas.

The solution is the basics of sand driving taken as far as you dare - VERY soft tyres and a LOT of momentum.

[101RRS]

but if there is no traction for any of the 4 wheels what would you expect to happen...? The TC does at that point apply brakes to all 4 wheels thus slowing the car and eventually stalling it pretty violently.

That is not the case - TC only works on wheels that are spinning faster than its opposite wheel. If all four wheels have lost traction and are spinnning at roughly the same speed then TC will not activate. If one of the wheels gains a bit more traction and slows it down so the other wheel is spinning faster then TC will momentarily brake that wheel and transfer power to the wheel that has traction.

TC cannot brake all four wheels at once.

Garry

[slug_burner]

Originally Posted by slug_burner View Post
A break of traction results in the application of the brakes to the spinning wheel, when the brake is applied to the spinning wheel that wheel stops spinning forcing the wheel on the other end of the axle to break traction if it is not already spinning.





No it doesn't (that is a pretty emphatic no), the wheel that has drive transferred to it will normally be stationary or turning much slower than the spinning wheel and when it gets drive it bites and pulls the vehicle (it can also bite and brake the surface of the sand and start digging in until the the TC applies the brake to that wheel). If the it looses traction (no drive) and it starts to spin faster than the other wheel, drive is transferred to the other wheel and so on. (Therefore digging with one wheel at a time on each axle unless there is enough traction to allow the vehicle to move on)

At no stage is any wheel that has traction braked - only those wheels, that not only have no traction but are spinning faster than another wheel with traction are braked.

Cheers

Garry

On dunes where the sand is expansive enough sand has pretty uniform traction properties, if one wheel brakes traction, forcing all the drive over to the other wheel will also result in a loss of traction.

This is a known issue and much has been written about it before.

[Phoenix12]

To all who have posted so far.......really good to get advice when needed ;) !I will expand on my experience and get back to basics.....:D

I was attempting to start in low 3rd with diff lock........and am aware that any gear lower is just too slow, but did not attempt high as on a previous day a mate had informed me that I was getting a lot of spin for no reward. This time the sand was pretty rutty and plenty soft after so many attempts up the dune by all drivers.....it was like a traffic light at some points with all comers lining up for a go !!

I did notice the TC light coming on and off intermittantly.....and found that I just could not get a run up. And we are not talking "ultra steep" at all.....just the usual steeper longer dune which I would certainly expect the defender to blow away.

I do believe that lowering the tyres would have been a option....I did get out and check them at 14psi (on the better gauge i have). But maybe 12 psi next time.

I am having Daniel at MULGO install a hard wired compressor on Friday morning so now am not so worried about going down the extra few psi.....(but rolling over the rim does not sound like fun !!) I will go back to Stocko on Sunday and attempt the same dune....and get back to you !!

As for operator error........absolutely 100 percent probability...... I really do need to get myself some lessons, and believe it would assist my skills in all areas of using my machine. Does any one know of a local mob (Newcastle) that do it ?

Cheers to all.

[slug_burner]

Try your local LR or 4x4 club, they usually run training days otherwise get another member with more experience to go out onto the sand with you.

[101RRS]

On dunes where the sand is expansive enough sand has pretty uniform traction properties, if one wheel brakes traction, forcing all the drive over to the other wheel will also result in a loss of traction.

This is a known issue and much has been written about it before.

You make some good points - the red bits - and for sure if there is no traction on any wheels TC is no use - exactly the same if TC was not activated or fitted to a vehicle. You would still be bogged - terrain is the fault not the TC.

TC works well in those situations where progress is stopped because of cross axles - if the terrain is bad all round Tc ain't going to help.

Cheers

Garry

[camel_landy]

Idle Jack, never head of it.

You have now... Every day is a school day. :D


That is not what Land Rover called it.

Errr.... Yes it is. (You might want to check where I work before you want to argue the toss ;))


My car will stall in all gears but low 1. In low 1 it may brake traction but will keep spinning regardless of what it's up against.

That's the combination of the idle jack & anti-stall. The increased revs & lower gearing means it will just keep going!!!

M