Joined: Mon May 05, 2014 11:50 am Posts: 1246
Vehicle: Vitara 1994
Posted: Tue Apr 14, 2015 10:56 pm
So most on here would disagree, but I have driven a few newer rides (with diff lock and without) recently and am very surprised how good some traction control systems are. For example a mate has a newer defender with TC and an arb rer diff lock. Unfortunately to engage the diff lock you have to disengage the ABS. Generally the car goes further with TC on than locked.
There are huge benefits to TC as well such as no understeer associated with front lockers etc. The major down side that I see is that the systems can overheat on long tough trails.
The 2014 Jimny has TC as far as I understand. I have not driven it so can't comment on that particular system.
So what are peoples opinions on TC. Will it ever replace locking differentials? Is it the way of the future? Discus.
Joined: Tue Jan 17, 2012 1:40 am Posts: 2979 Location: Darwin, NT
Vehicle: WT sierra, GU CRD
Posted: Wed Apr 15, 2015 12:49 am
I think you're crossing wires there and missing his point. He's talking about the systems that come in when you engage low range, that brake the wheels that are slipping to get drive, rather than the ones that stop "fun" in hi range caused by big inputs. Apparently LR's system is quite good. Well the reviews said it was anyway.
Joined: Mon May 05, 2014 11:50 am Posts: 1246
Vehicle: Vitara 1994
Posted: Wed Apr 15, 2015 2:26 am
Marko_SJ wrote:
I think you're crossing wires there and missing his point. He's talking about the systems that come in when you engage low range, that brake the wheels that are slipping to get drive, rather than the ones that stop "fun" in hi range caused by big inputs. Apparently LR's system is quite good. Well the reviews said it was anyway.
In the case of non-heavily modified or stock vehicles i think its a real winner. My mates Dmax ute is unbelievably capable stock as a rock and its 100% down to the TC system applying the brakes etc. It really is quite impressive to watch... all the driver needs to do is keep a steady foot on the accelerator and let the system work out which wheel has grip. So in the case of a jimny, if it has this sort of low speed TC it will likely be very beneficial, however we all know suzuki are only doing this in order to continue to sell the car so they will have fitted the cheapest, least intelligent system possible just to make do - so it is likely it will be one of those on-road focused systems that cuts in right when you don't want it to =)
Land Rover actually removed the linkage to the centre diff lock on later Disco 2s, reasoning that the traction control worked so well it didn't need it. Though right at the end of production they reinstated the diff lock. Dunno what disco 3+ and modern rangies run, I've never really paid attention to those. I was pretty impressed with the disco 4 on the first Low Range DVD how crawling up that scrabbly hill it hardly spun a tyre until it got to that rock step where it couldn't go any further.
A hot setup for Rover guys is running ATBs instead of diff locks to increase the effectiveness of the traction control, apparently it works pretty well. Something like that seems like the way of the future to me. My quad bike has a kind of ATB in the front and the way it locks the diff up with a light touch on the front brake is just magic, with some sort of traction control and those front and rear it'd be a doddle to drive and maneuver on any surface. In mud it always spins both, it's only when it lifts a wheel it acts like a normal open front diff and it steers very nicely for a quad bike (quads almost all run spool rear ends, so they're pretty under/oversteer prone).
I talked to a Suzuki dealer about the Jimnys, he said it's not traction control, it's ESC. He said it wont help you out offroad and it's disabled in low range range anyway.
Joined: Mon May 05, 2014 11:50 am Posts: 1246
Vehicle: Vitara 1994
Posted: Wed Apr 15, 2015 1:32 pm
I have not driven a 2014+ Jim yet but my understanding is that it runs the esc above 30kmh and when engaging low gear and doing below 30kmh it uses the braking TC I was referring to. It would be a waste to put one on without the other as it's just a case of programming the system.
Sideways I have spent some time behind the wheel of a disco 2 and it's not bad, but no where near as good as the new defender system or even the xterra system. I think the disco 2 would have benifited from a center locking diff.
When old mate bought his xterra he got given a loan car with the factory locking rear diff and being a loan car we went out and deliberately tried to get the car stuck to compare the diff lock on an off. In some situations the car went further with the diff lock off. For example a boggy sandy hill undeflated the TC would alternate spinning wheels helping the car crab up the hill where the diff lock would big down. I was a little surprised. However by the same token I have seen the new patrol (same manufacture) get stuck due to the TC. I was camping on a rather boggy beach and woke up to a patrol trying to make his way down the beach with undeflated low profile tyres. You could see it spinning and crabbing along and then engine would die and the car would just come to a halt. The behavior of the car was as if the driver lifted and slammed on the brakes. In fact this is what I thought the driver was doing before I spoke to him. So it's strange as I never felt that same halt on the same brand of car and we where giving it to it also car stunk of brakes etc.
It's the way of the future Wether we like it or not. We will learn to use it. Get around it, find its advantages etc. Smart aftermarket bods will soon sell mods and back yard hacks will find ways, too. I used to be scared of efi off road, I guess I will have to get used to Tc in future.
Joined: Tue Dec 06, 2011 9:30 am Posts: 2155 Location: Nhulunbuy 0880
Vehicle: 2010 jimny
Posted: Thu Apr 16, 2015 12:51 pm
TC controlled in this manor stops the wheel in pulses. this increases cv and axle breakage frequency by lining the peak torque applied. when systems get advanced enouth to apply only the correct pressure to equalise the speed between 2 wheels without pulseing will they be truly effective
_________________ your daily dose of questionable sanity
when the xv come out you could see the tc working in the add when it was climbing that hill at the end when the wheel spins you see the brake grab. there a few guys in the subaclub that are happy with the tc in their outbacks.
I have no idea why you'd think Subaru's traction control is in any way superior to anyone else's. When I had my 2005 STi (which had three LSD's but thankfully no traction control) I'd get a loner Outback or whatever, which invariably had traction control. It was universally terrible. Drive off an angled driveway under power and it would shut the motor down for what felt like about 25 minutes until it worked out that all wheels were safely on the ground. Ugh. Slow, clunky and dimwitted.
BMW's TC is generally pretty good, but in 80,000km or so in my X3 I don't recall it ever really activating, the Xdrive torque management seemed to be much smarter than braked traction control even with 550Nm.
The TC on the current Defender is incredibly good.
Many years ago a technical trainer at Bosch did some experiments with Bosch TC. He could get it to maintain wheel speeds within 5% of each other. That's very aggressive, and would feel like a very tight LSD in practice. Murder on brakes, no doubt, but I'm sure it was very effective. He also disabled the torque limiting on the TC on his 350Z, so it wouldn't cut power when the TC sensed excessive wheelspin.
Potentially, TC, or more properly torque vectoring, could be more effective than a locker as it prevents tyre slip at all. With a locker, we're frequently reducing grip on one wheel to provide grip on another. (watch a car with a locker engaged turning on a loose surface - one wheel is overspeeding which means it has less grip than a wheel that's matching road speed)
Ferrari have set up their TC to "learn" how much traction a surface has. Do a hard launch, it might slip or grip. Do another in succession and it will apply what it's learned and feed just enough torque in to keep both wheels at the limit of traction. That's so far ahead of a mechanical locker it's silly.
Joined: Tue Dec 06, 2011 9:30 am Posts: 2155 Location: Nhulunbuy 0880
Vehicle: 2010 jimny
Posted: Wed Apr 22, 2015 10:00 am
next step is 4 variable frequency drives powering 4 electric motors, inside 4 rims, powering 4 wheels. torque is controlled all the time. breaking is regenerative and discs for emergency. electricity comes from whatever you like, battery's for cars doing short trips, hydrogen for trucks, 4x4's and long range cars.
solar/pedels for hippies.
_________________ your daily dose of questionable sanity
Joined: Thu Jun 02, 2011 9:53 pm Posts: 361 Location: Independence, MO USA
Vehicle: 1993 RHD Suzuki Escudo Tintop
Posted: Thu Apr 23, 2015 3:19 pm
At first I thought Traction Control was some sort of marketing gimmick. Once I saw it in action, I saw the value.
Way back in the early 2000s when Toyota introduced the new FJ Cruiser to the world, I had the opportunity to drive one provided by a travelling demo team from Toyota. They showed up at a ZookiMelt event at The Badlands ORV park.
As an explanation, the Badlands was originally a quarry. However, they also had used the property as a place to dump sand dredged from a nearby river. Giant piles of sand!
The Toyota reprsentative first drove a stock FJ up the face of one of these incredibly steep dunes that even a prepared Samurai/SJ413/Sierra would struggle to drive up with me sitting in the passenger seat. It was pretty amazing. Then they handed me the keys and let me try it. It was quite easy to make the climb - you could feel the traction control adjusting the speed of the wheel rotation on all four corners as each wheel lost or gained traction. It was described a an ABS braking system that worked in reverse.
Joined: Mon May 16, 2011 7:03 pm Posts: 686 Location: Brinkworth, England
Posted: Thu Apr 30, 2015 6:26 am
atari4x4 wrote:
torque vectoring FTW
From what I've seen torque vectoring is usually used on a clutch pack AWD like the Haltech system, I don't know how well that would stand up to a lot of off-road abuse.
Joined: Mon May 16, 2011 7:03 pm Posts: 686 Location: Brinkworth, England
Posted: Thu Apr 30, 2015 6:30 am
Gwagensteve wrote:
The TC on the current Defender is incredibly good. Many years ago a technical trainer at Bosch did some experiments with Bosch TC. He could get it to maintain wheel speeds within 5% of each other. That's very aggressive, and would feel like a very tight LSD in practice. Murder on brakes, no doubt, but I'm sure it was very effective. He also disabled the torque limiting on the TC on his 350Z, so it wouldn't cut power when the TC sensed excessive wheelspin. Steve.
When the LR system was first released it was programmed to disable itself when it determined that the brakes may be overheating. At a press day that lead to an LR careering down a hill and crashing into a bunch of others at the bottom - I believe they've fixed that now.
Joined: Mon May 05, 2014 11:50 am Posts: 1246
Vehicle: Vitara 1994
Posted: Mon Aug 17, 2015 11:28 pm
So I ended up buying a new jimny and have done around 3500kms with it. Also tried to test the TRC where possible. So far I have found on road I notice nothing, I generally hate esc in cars for on road driving, but in the Jim it's just not noticeable I don't think I have ever felt it kick in. I guess 62.5kws helps with this.
Offroad I notice it and find it helpful. If you just mash the gas the system will give up and single peg, but if you keep a nice steady foot on the gas you feel it adjusting and braking the wheels that need braking. I haven't consciously tested it with a wheel in the air yet to see what it does so I guess that wi be next.
Does it replace lockers? I would say no, it's not that advanced but it does bridge the gap and no longer makes lockers a necessity. For those wanting not wanting to go lockers it's rely worth it.
Joined: Mon May 05, 2014 11:50 am Posts: 1246
Vehicle: Vitara 1994
Posted: Tue Aug 18, 2015 2:52 pm
Rhinoman wrote:
Does the ESC work in 4-low?
According to the manual ESC is turned of and brake traction control is activated. Tbh I am not even sure mine even has esc on high range as I have need felt it kick in and there is no button to turn it off and I never see the light turn on even when I switch on the ignition. But I do feel the brake TRC kick in when low range is engaged.
Offroad I notice it and find it helpful. If you just mash the gas the system will give up and single peg,
this is the complete opposite of my experience with every traction control quipped vehicle I have ever driven.
Traction control works on differential of wheelspeed. The higher differential wheelspeed it sees, the harder it applies. If it "single pegs" under full throttle, it's not working properly. Which might be a good thing, but it's not how its supposed to work, or actually works in my experience.
I'd be extremely surprised if ESC was detectable at low range speeds.
Joined: Mon May 05, 2014 11:50 am Posts: 1246
Vehicle: Vitara 1994
Posted: Wed Aug 19, 2015 4:39 pm
Gwagensteve wrote:
vet 180 wrote:
Offroad I notice it and find it helpful. If you just mash the gas the system will give up and single peg,
this is the complete opposite of my experience with every traction control quipped vehicle I have ever driven.
Traction control works on differential of wheelspeed. The higher differential wheelspeed it sees, the harder it applies. If it "single pegs" under full throttle, it's not working properly. Which might be a good thing, but it's not how its supposed to work, or actually works in my experience.
I'd be extremely surprised if ESC was detectable at low range speeds.
Steve.
I can see how you would come to that conclusion for slow speed rock crawling. I am yet to test it out on a challenging real slow speed wadi, I am interested to see how it feels. I get that the system relies on a difference in wheel speed. However most of the testing so far has been either in the soft low speed technical dunes or very slippery sandy cliff faces. In these situations you can feel the ABS pulsing and the car crab forward. If you just mash the throttle the wheel speed goes over 30kph and the brake traction disengages and the car will single peg. Most 4x4's with low range brake traction act in a similar way, some needing more throttle than others.
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