Let's talk Traction Control

[Chris Stoffel]

Chris,

Are you saying that TC can do all the obstacles that DL can?


Sent from my SM-G998B using Tapatalk

I think so Shane, yes. With a little bit of talent. But one must know how to drive a TC vehicle. Not that know but I will find out soon.

[KurtG]

Very true Manny. The Paj from 2014 up has TC and DL.

I have had more success with TC in loose rocky inclines (like Road to hell), but DL was way better on solid rock inclines like Briekmerk.

The Paj switches off TC when DL is engaged so if you have decent rear axle grip, the DL is the bomb, in certain situations when you need all 4 wheels to help with traction, then the TC was better (in my experience).

If I was to choose what to have if only one option was available, it would be the DL.

[Chris Stoffel]

A great and experienced 4x4 wheeler mentioned on another thread that with TC the driver needs to ad a little momentum and not lift off the throttle when the wheels start losing traction. I watched some YouTube videos with the New Jimny TC and it is clear that a bit of momentum is the way to go. The TC do not engage immediately but none off them do. Some criticism on the Jimny TC is that it it do activate a bit late.

[Apocalypse]

there are a whole lot of acronyms that are somewhat confusing as a lot of manufacturers use different ones for the same things.

ABS - Anti lock Braking system is the basic nanny function - Early ones had speed sensors in all 4 wheels , when one of the wheels was turning more slowly than the others it would ease off pressure to that brake - The problem was if you stamped on the brake and locked all 4 up, it just believed it was stopped and did nothing. Horrible on Gravel as it would just give you no brakes at all (early ones had a switch to turn off). Later versions have a logic function that reads deceleration and prevent that from happening, and also 'reads' the surface traction and decides how much 'lock' a wheel can have to allow some locking/dragging on loose surfaces.

this is extended further to EBD - whereby the computer calculates the maximum force to apply to any given wheel under emergency/panic braking.

The next step after ABS was to use the brakes as a kind of limited slip diff across an axle. eLSD or electronically braked diff is a common name for this feature, but there are lots. The same 4 sensors measure wheel slip across the wheels and apply braking force to the faster spinning driven wheel to transfer torque across the differential to the slower wheel . Not to be confused with an Electronic Limited slip diff, or a mechanical limited slip diff. This is a TRACTION AID rather than traction control.

Actual Traction control requires either electronic throttle or injection - the system will cut power to the engine by closing the throttle or retarding the timing to limit power and thus wheelspin - it allows a certain amount of wheel spin in launch control modes.

Then there is Stability control - ESP, ASC are common names. That uses the brakes as well as controls power to control the stability of the vehicle when it leans or slides dramatically.

They are ALL a pain in the arse if you want to have some proper fun. with the exception of eLSD they all interfere with offroad driving and reduce the performance of the vehicle. Totally useless for mud or sand or even rocks. Great for Mom's taking the kids to the mall.

They will make even the most useless driver look pretty good up to the limit of the system though. But those limits are not very high.

even the eLSD function is a bit of a pain sometimes, but mostly useful.

Some vehicles will have electronically controlled torque splits across differentials (whether left/right or front rear) which can allow up to 100% of torque to transfer to a single wheel via various systems - clutches or variable viscosity oil amongst them.

But every system listed above requires a wheel to slip before it will kick in, then it kicks out to 'test' if there is traction.

In the case of a mechanical LSD and most electronically controlled diff slip systems it will ensure that each wheel on the axle will receive a minimum amount of torque that is set by the drag on the slipping device, whatever it might be , so there is never a no torque situation on a wheel (but that means you still get 100% slip to one wheel, which many imagine doesn't happen when they see e.g. 70/30 torque split)


Diff locks are the only way (whether mechanically engaged or electronically activated via clutch etc) that you can have 100% of torque on one side of a differential at all times, and where both half shafts will turn at the same speeds at all times.

As clever as nanny systems might get - and vehicles like the new Land Rovers as an example are very good - you simply cannot beat a fully locked vehicle for traction on loose or uneven surfaces.

[Saxj]

In most situations TC works great. There are 2 problems with it though, and in both situations diff locks, and sometimes open diffs are better.

1. It's too slow to kick in. This causes you to lose momentum in situations where that momentum is critical.
2. It stops wheels. e.g. In sand, mud or wet grass you need all the wheels to be moving (sometimes spinning is necessary).

[Saxj]

Chris,

Are you saying that TC can do all the obstacles that DL can?


Sent from my SM-G998B using Tapatalk

No it can't

[Shane]

Pretty much what I've been able to figure out since this thread.

Any obstacle requiring a fair amount of sustained momentum requires dl..

Sent from my SM-G998B using Tapatalk