Defender xtreme traction control

Just to throw it out there...

Tc sapping forwards power ummmmmm...


ok so TC works by briefly applying the brakes to the wheel(s) that is spinning... The brain box works out which wheel is spinning via the ABS sensors then applies the brakes to any wheel going x% faster than the slowest wheel.

with the CDL on because (barring something broken) both axle diffs are turning at the same speed in theory it should only ever be applying the brakes to one wheel of the axle at a time....

as I see it this does 2 things for me...

1. The free spinning wheel(s) is slowed down to the point where it is regaining traction. (AFAIC if a wheel is spinning forwards its not offering lateral traction either) which is good.

2. by applying a braking force to the spinning wheel its redirecting torque to the wheel that isnt going so fast because it has the restrictive effort of the ground acting on it. This provides drive, also good.

now If I turn the CDL off thats a different kettle of fish...

as both axle diffs are able to turn at differeing rates the axles can, in theory, turn at 2 different rates which means you can now have up to 3 of the 4 wheels being braked at the same time That I can see being bad as now you will have a braking force applied across an axle which I can see sapping forwards movement but not power.

you seem to loose power when the TC is on as the vehicle brakes are being applied to keep the wheel speed equal to the road speed.

now IMHO.

If your trying to get through an obstacle (call it a long soft stretch of sand) by sheer horsepower and momentum alone TC isnt going to help you get through but will limit the amount by which you get bogged. because instead of letting your wheels spin and chew the ground out from under you they will slow down and stop.(the hummers can be setup to automatically pick neutral) If you didnt have enough momentum and power on in the begining to make it through with TC then you probabley werent going to make it through without TC.

However the best reason I can think of for being able to switch it off, and Id want to be able to do it on the fly, is when recovering the vehicle when I want to be able to spin the wheels a little (especially on wet clay) or when Im being recovered and want the wheels turning to assist.


or Am I too "driving miss daisy" when it comes to the loud pedal offroad?

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Originally Posted by Blknight.aus

Just to throw it out there...

Tc sapping forwards power ummmmmm...


ok so TC works by briefly applying the brakes to the wheel(s) that is spinning... The brain box works out which wheel is spinning via the ABS sensors then applies the brakes to any wheel going x% faster than the slowest wheel.
?

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Just on this point, it will try and brake the spinning wheels as a first course of action. If this is unsuccessful and it cannot control what it believes to be wheel spin as a last resort is can reduce the throttle.

We drove off piste through the simpson last year and only at one point do I remember feeling as though the throttle was being reduced on me and even then I wasn't really sure, it was so subtle it was just a hunch. Many road cars will intervene severely if they cannot control wheelspin, and the whole thing seems to die. LR TC as fitted to the fender is not like this at all. :)

The other advantage of TC is it can stop the spin-grip-snap syndrome that breaks expensive bits :(

:)

Once again.. IMHO not as good as lockers but much better than open diffs.

My TC experience says swamps is where TC can let you down. 5 attempts to attack 100+ meters deep ruts of mud in Rocklands... went in, bogged, winched back. In total 7 hours of winching and Tirfor finished the job.

Or may be I have to learn how to drive with TC in swamp :)

Cheers,
Ruslan

the TC only works under 37kph.

mine dosent even turn on anymore since the detroit and true track.

cheers phil

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Originally Posted by Captain_Rightfoot

Just on this point, it will try and brake the spinning wheels as a first course of action. If this is unsuccessful and it cannot control what it believes to be wheel spin as a last resort is can reduce the throttle.

We drove off piste through the simpson last year and only at one point do I remember feeling as though the throttle was being reduced on me and even then I wasn't really sure, it was so subtle it was just a hunch. Many road cars will intervene severely if they cannot control wheelspin, and the whole thing seems to die. LR TC as fitted to the fender is not like this at all. :)

The other advantage of TC is it can stop the spin-grip-snap syndrome that breaks expensive bits :(

:)
Once again.. IMHO not as good as lockers but much better than open diffs.

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The WSM has quite a detailed write-up on ABS & TC and makes no reference to reducing engine power.

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Originally Posted by Micka

I agree.

<snip>

Bottom line was that the factory TC was just as good as the HTC, but it overheated LONG before the HTC did.

<snip>

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The D2 TC doesn't have any heat sensors - it guesses the amount of heat being generated.

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Originally Posted by discowhite

the TC only works under 37kph.

mine dosent even turn on anymore since the detroit and true track.

cheers phil

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mine buzzes and the light comes on at 100kmh on the dirt, especially on corrugations????

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Originally Posted by Robocop

I can see the advantages and dis-advantages of having this option on your vehicle. Has anyone pulled the fuse when of road or rigged up ABS/Traction control switch?

Rob

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Yep, on my D2 - today, after being reminded that its been on my to-do list for a while when I was stopping a bit quickly on a dirt road, then ABS/EBD cut-in and I was no longer stopping so quickly.

I've rigged-up a switch in the line from the SLABS ecu to the ABS pump relay coil (beats jumping out and pulling the relay). It lights-up the dash until next startup. Even if its switched back on, ABS/TC doesn't work again until next startup. The WSM says that EBD will still be partially active.

I don't intend to drive with ABS/TC disabled, but have it there as an option if I'm getting stuck and it can be disabled on the fly.

The only testing I've done so far is a small comparison of an emergency stop from 40kph on a sandy track, and both times appeared to stop at the same spot, although I can't be sure that I applied the brakes at identical times. Hard acceleration over rutted hard gound did not invoke TC, as expected.

no problems getting TC to cut in on my driveway,,
though the immovable chicane becomes a worry:eek:

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Originally Posted by crump

mine buzzes and the light comes on at 100kmh on the dirt, especially on corrugations????

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Yep, up to 100kph. but dIfferent parameters over 50kph.