FROM: "Ziggy" SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 29 Apr 2002 06:18:05 GMT ORGANIZATION: BigPond Internet Services (http://www.bigpond.net.au) NEWSGROUPS: aus.cars.offroad "Ballina boy" wrote in message news:3c9e5594@news.comindico.com.au... > This was a comment made about the Ford Escape. > > "But don't kid yourself, for a softroader it is a capable vehicle especially > because the centre differential can be locked. > Most soft roaders - the likes of Freelander's, CRV's, > > Liberty's etc.. do not have this ability. > > > Correct me if I'm wrong, but with the centre diff locked aren't you limited to > 50/50 to the wheels? So what happens when you get diagonal cross up? > Isn't it better that you have a viscous coupling so that the front and rear > can vary as much as 95/5, 5/95, linked with traction control and put the > power to the wheels that have the best traction, Freelander has this ability > and works > superbly. > Scotty > > Correct! FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 29 Apr 02 12:55:38 GMT NEWSGROUPS: aus.cars.offroad In article , "Ziggy" wrote: > >"Ballina boy" wrote in message >news:3c9e5594@news.comindico.com.au... >> This was a comment made about the Ford Escape. >> >> "But don't kid yourself, for a softroader it is a capable vehicle especially >> because the centre differential can be locked. >> Most soft roaders - the likes of Freelander's, CRV's, >> > Liberty's etc.. do not have this ability. >> >> >> Correct me if I'm wrong, but with the centre diff locked aren't you limited to >> 50/50 to the wheels? So what happens when you get diagonal cross up? >> Isn't it better that you have a viscous coupling so that the front and rear >> can vary as much as 95/5, 5/95, linked with traction control and put the >> power to the wheels that have the best traction, Freelander has this ability >> and works superbly. >> Scotty >> >> >Correct! > First: a viscous *coupling* (instead of the much better concept of a viscous LSD on top of a normal diff) means that it only engages the other axle *when*, *after* and _as long as_ slip occurs. On fragile surfaces like sand and ice this can be way too late, in a fast driven slippery corner idem ditto. Nothing beats a true (open) center diff onroad, or a locked one offroad (unless in tight corners). Second: traction control spoils 50% of available power/torque....with a heavily loaded vehicle you won't get as far uphill as you can with a mechanically locked vehicle (or even one with viscous coupling). For more about this see: http://www.a1.nl/phomepag/markerink/tad_elec.htm -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Tue, 30 Apr 2002 09:27:22 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > First: a viscous *coupling* (instead of the much better concept of a viscous LSD > on top of a normal diff) means that it only engages the other axle *when*, > *after* and _as long as_ slip occurs. On fragile surfaces like sand and ice this > can be way too late, in a fast driven slippery corner idem ditto. Nothing beats > a true (open) center diff onroad, or a locked one offroad (unless in tight > corners). > > Second: traction control spoils 50% of available power/torque....with a heavily > loaded vehicle you won't get as far uphill as you can with a mechanically locked > vehicle (or even one with viscous coupling). For more about this see: > > http://www.a1.nl/phomepag/markerink/tad_elec.htm Are we talking constant or permanent 4wd here? as I've heard comments saying that with a viscous coupling you get an "on again, off again" effect with them. I have given some thought to this and could understand this with a constant 4wd system but with a permanent 4wd you wouldn't get this. In my instance, the Freelander is a permanent 4wd and with the set up of the diffs, it has no less than 5% of power going to the back wheels and in the instance that the fronts do slip, the back can have as much as 95%, so you don't get that off again effect, it just moves the power where it is needed most. I agree with you that if something that is mechanically locked would be stronger, but than you have a disadvantage of not being able to move the power around where it is needed. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Tue, 30 Apr 02 01:16:40 GMT NEWSGROUPS: aus.cars.offroad In article <3ccdd59d@news.comindico.com.au>, "TD4GRUNT" wrote: > >> First: a viscous *coupling* (instead of the much better concept of a viscous LSD >> on top of a normal diff) means that it only engages the other axle *when*, >> *after* and _as long as_ slip occurs. On fragile surfaces like sand and ice this >> can be way too late, in a fast driven slippery corner idem ditto. Nothing beats >> a true (open) center diff onroad, or a locked one offroad (unless in tight >> corners). >> >> Second: traction control spoils 50% of available power/torque....with a heavily >> loaded vehicle you won't get as far uphill as you can with a mechanically locked >> vehicle (or even one with viscous coupling). For more about this see: >> >> http://www.a1.nl/phomepag/markerink/tad_elec.htm >> >> > >Are we talking constant or permanent 4wd here? as I've heard comments saying >that with a viscous coupling you get an "on again, off again" effect with >them. Yup, that's what I meant with my 'when, after and as-long-as' comment above. Only applies to couplings, which does *not* comply with my strict definition of fulltime-4wd ('All wheels are driven all the time', in contrast to the old/original definition of 'can be left engaged all the time' (in those days there were no viscous/hydraulic couplings, only center diff or locked 4wd)). >I have given some thought to this and could understand this with a >constant 4wd system but with a permanent 4wd you wouldn't get this. I think you just invented one more definition....;)) To most folks, including me, 'constant' and 'permanent' are one and the same (I *could* imagine constant being my strict definition, and 'permanent' the old one, but that is way to subtle for others) >In my >instance, the Freelander is a permanent 4wd No, it has not....it has automatic parttime 4wd.... (most of the coupling-concepts even bind quite noticeably in tight/fast corners) >and with the set up of the >diffs, it has no less than 5% of power going to the back wheels and in the >instance that the fronts do slip, the back can have as much as 95%, so you >don't get that off again effect, it just moves the power where it is needed >most. But only *when*, *after* and _as long as_ slip occurs.... >I agree with you that if something that is mechanically locked would be >stronger, but than you have a disadvantage of not being able to move the >power around where it is needed. >Scotty As I said, it's much nicer to have that viscous clutch as an LSD, on *top* of a normal center diff....that way you start with 50/50, and have much less chance of spinning a wheel in the first place than if you start with 95/5.... -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Tue, 30 Apr 2002 17:45:25 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > I think you just invented one more definition....;)) > To most folks, including me, 'constant' and 'permanent' are one and the same (I > *could* imagine constant being my strict definition, and 'permanent' the old > one, but that is way to subtle for others) Constant and permanent are not the same, a constant 4wd is driven by 2 wheels and only when slip is detected then it is driven by the other 2 and becomes 4wd, it *constantly* monitoring slip, as permanent it is permanently in 4wd 100% of the time, and as far as I know this is a Land Rover trait, the only one to have permanent 4wd. > >In my > >instance, the Freelander is a permanent 4wd > > No, it has not....it has automatic parttime 4wd.... > (most of the coupling-concepts even bind quite noticeably in tight/fast corners) Have a look at a Land Rover web site and you will find it isn't automatic part time but a permanent 4wd. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Tue, 30 Apr 02 14:23:14 GMT NEWSGROUPS: aus.cars.offroad In article <3cce4a56@news.comindico.com.au>, "TD4GRUNT" wrote: >> I think you just invented one more definition....;)) >> To most folks, including me, 'constant' and 'permanent' are one and the same (I >> *could* imagine constant being my strict definition, and 'permanent' the old >> one, but that is way to subtle for others) >> > >Constant and permanent are not the same, a constant 4wd is driven by 2 >wheels and only when slip is detected then it is driven by the other 2 and >becomes 4wd, it *constantly* monitoring slip, as permanent it is permanently >in 4wd 100% of the time, and as far as I know this is a Land Rover trait, >the only one to have permanent 4wd. Oh no, you now even reversed the only subtle logical difference there was....8-)) As in 'constant driven' and 'permanently engaged' (the other way around ('permanently driven' & 'constant engaged') is semantically worse IMNSHO) Nor is it an exclusive LR-trait btw.... >> >In my >> >instance, the Freelander is a permanent 4wd >> >> No, it has not....it has automatic parttime 4wd.... >> (most of the coupling-concepts even bind quite noticeably in tight/fast corners) >> > >Have a look at a Land Rover web site and you will find it isn't automatic >part time but a permanent 4wd. All axles that only engage *when*, *after* and _as long as_ slip occurs are automatic parttime-4wd....as the words say: 'part of the time'. And that 5% limit is only present to prevent drivetrain slop, and banging when engaging. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Wed, 1 May 2002 09:38:42 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > >Have a look at a Land Rover web site and you will find it isn't automatic > >part time but a permanent 4wd. > > All axles that only engage *when*, *after* and _as long as_ slip occurs are > automatic parttime-4wd....as the words say: 'part of the time'. That is why the rear diff ratio is different to the front, so that it in sense tricks the viscous coupling that there is slip and drive the rear wheels....Bob's your Uncle...you have permanent 4wd! > And that 5% limit is only present to prevent drivetrain slop, and banging when > engaging. There's nothing to engage! it's always in 4wd Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Wed, 01 May 02 14:28:56 GMT NEWSGROUPS: aus.cars.offroad In article <3ccf29c3$1@news.comindico.com.au>, "TD4GRUNT" wrote: > >"> > >> >Have a look at a Land Rover web site and you will find it isn't automatic >> >part time but a permanent 4wd. >> >> All axles that only engage *when*, *after* and _as long as_ slip occurs are >> automatic parttime-4wd....as the words say: 'part of the time'. >> > > >That is why the rear diff ratio is different to the front, so that it in >sense tricks the viscous coupling that there is slip and drive the rear >wheels....Bob's your Uncle...you have permanent 4wd! While that is a known trick, it falsifies the claim of an initial 95/5 ratio....;)) >> And that 5% limit is only present to prevent drivetrain slop, and banging when >> engaging. > > >There's nothing to engage! it's always in 4wd 5% is just enough to avoid having to drag it along....just a wee bit more than idling along....:)) A proper fulltime system has a 50/50 to 33/66 ratio (the latter is questionable on steep/slippery downhill sections however, unless it can be locked completely....uphill it's nice....:)). Only such ratio's allow the best spread torque in fast driven corners....preventing slip is the key issue here, not curing it (nor disengaging as soon as it has cured it). See also another thread in this newsgroup, about the Honda CRV....same concept. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Wed, 01 May 02 14:35:59 GMT NEWSGROUPS: aus.cars.offroad In article , w.j.markerink@a1.nl (Willem-Jan Markerink) wrote: >In article <3ccf29c3$1@news.comindico.com.au>, > "TD4GRUNT" wrote: >> >>> >Have a look at a Land Rover web site and you will find it isn't automatic >>> >part time but a permanent 4wd. >>> >>> All axles that only engage *when*, *after* and _as long as_ slip occurs are >>> automatic parttime-4wd....as the words say: 'part of the time'. >>> >> >> >>That is why the rear diff ratio is different to the front, so that it in >>sense tricks the viscous coupling that there is slip and drive the rear >>wheels....Bob's your Uncle...you have permanent 4wd! > >While that is a known trick, it falsifies the claim of an initial 95/5 >ratio....;)) (in the context of *significant* drive to the rear wheels that is....it really only exists to avoid slop) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Thu, 23 May 02 13:15:48 GMT NEWSGROUPS: aus.cars.offroad In article <526e114e.0205230345.2ff301b5@posting.google.com>, prometheus_au@excite.com.au (Dave) wrote: >w.j.markerink@a1.nl (Willem-Jan Markerink) wrote in message news:< >> >I have given some thought to this and could understand this with a >> >constant 4wd system but with a permanent 4wd you wouldn't get this. >> >> I think you just invented one more definition....;)) >> To most folks, including me, 'constant' and 'permanent' are one and the same (I >> *could* imagine constant being my strict definition, and 'permanent' the old >> one, but that is way to subtle for others) > >Well if that's the case "most folks" would be wrong. Constant 4WD and >Permanent 4WD are not the same thing.... Well, since most folks seem to listen to markedrones, trying to sell cheap (reactive) 4wd systems as the best thing since sliced bread, they *are* wrong. And as I said, in *my* definition 'constant' is a higher grade (active) than 'permantent' (reactive). If yours is even the other way around, you are also semantically wrong (and better consider them equal). -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Fri, 24 May 2002 11:18:14 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad "Dave" wrote in message news:526e114e.0205230345.2ff301b5@posting.google.com... > w.j.markerink@a1.nl (Willem-Jan Markerink) wrote in message news:< > > >I have given some thought to this and could understand this with a > > >constant 4wd system but with a permanent 4wd you wouldn't get this. > > > > I think you just invented one more definition....;)) > > To most folks, including me, 'constant' and 'permanent' are one and the same (I > > *could* imagine constant being my strict definition, and 'permanent' the old > > one, but that is way to subtle for others) > > Well if that's the case "most folks" would be wrong. Constant 4WD and > Permanent 4WD are not the same thing.... > > Dave. Here,here!! Dave. I agree. They are different because constant has a lazy axle until slip is detected, and permanent, all wheels are "permanently" driven up to some degree. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 02 13:15:03 GMT NEWSGROUPS: aus.cars.offroad In article <3ced9390@news.comindico.com.au>, "TD4GRUNT" wrote: >Here,here!! Dave. I agree. They are different because constant has a >lazy axle until slip is detected, and permanent, all wheels are >"permanently" driven up to some degree. >Scotty Jeezz....you too get a semantical spanking! *If* you want to distinguish 'permanent' and 'constant', then at least refer to 'permanently engaged' and 'constant driven'....'permanently driven' & 'constant engaged' makes *much* less sense, semantically speaking. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: prometheus_au@excite.com.au (Dave) SUBJECT: Re: Locked centre diff v traction control DATE: 23 May 2002 19:42:00 -0700 ORGANIZATION: http://groups.google.com/ NEWSGROUPS: aus.cars.offroad Definitions of 4WD Systems... PART-TIME 4WD Part-time 4WD is th most basic system available. Quite simply, it gives the driver the choice of driving around in 2WD or 4WD. that sounds great until you realise that you really can't engage 4WD on the road unless it's slippery - and when you do, you lock the front and rear axels together - great for straight ahead traction, but virtually impossible to steer around a corner on tarmac without producing torque wind-up in one of your axels. Most modern systems, through the use of automatic hubs have "Change on the fly" capability so you can engage 4WD while the vehicle is moving (an example of this is the Suzuki Vitara and Kia Sportage). But with some, you may still have to stop or slow down considerably to engage it. It's also important to note that may of the safety advantages of driving a 4WD do not apply to part-time 4WDs. This is for the reason that a 4WD system makes no difference - unless it is engaged - which may not be the case in an emergency situation. Why choose it? Primarily because it's simple, less costly to build and therefore cheaper to buy. FULL-TIME 4WD Full-time 4WD offers a 2WD mode for normal driving, an "auto 4WD" mode for changing conditions and a "4WD Lock" mode for the tough stuff. The automatic aspect of this system makes it convenient for many drivers, as the system automatically changes to 4WD when the vehicle senses the driving conditions change. By placing some type of viscous coupling between the front and rear axels, full-time 4WD can work automatically, depending on driving conditions (Examples include the Escape, Tibute, Pathfinder, X-Trail). These systems detect wheel slippage and progressively lock the front and rear axels together to optimise traction. But full-time 4WD, especially in the automatic mode, still has a disadvantage off-road. On steep hills and over large rocks, the system can shift power from axel to axel at the wrong time, upsetting the vehilce's balance and cause a loss of traction. the manual "lock" feature of these vehilces when fitted and engaged overcomes this. PERMANENT 4WD Permanent 4WD is definitely an improvemnet over full-time 4WD - it has no 2WD mode. Becaus the vehicle is always in 4WD, you never have to determine whether the conditions are right for 2WD or 4WD (examples include Discovery and Freelander). On -road, permanent 4WD automatically delivers power where it's needed with no driver action required. Off-road you can lock the centre diff and if necessary engage low range to maxime traction and control. The biggest difference between Full-time and Permanent 4WD systems is that in a permanent 4WD system all 4 wheels are driving the car at any given stage. A slip diff (or on more modern vehicles - a viscous coupling) between the front and rear axels stops axel wind-up on corners and can be over-ridden by the diff lock. ******************* So what's best for you? If you are planning to spend most of your time on-road and will not encounter much extremes you might consider a part time 4WD. Throw in some sand, rain or snow or some mountainous tracks and the argument for a full-time or permanent 4WD system becomes compelling. ******************* Cheers Dave FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 02 15:00:19 GMT NEWSGROUPS: aus.cars.offroad In article <526e114e.0205231841.25ac9739@posting.google.com>, prometheus_au@excite.com.au (Dave) wrote: >Definitions of 4WD Systems... > >PART-TIME 4WD > >Part-time 4WD is th most basic system available. Quite simply, it >gives the driver the choice of driving around in 2WD or 4WD. that >sounds great until you realise that you really can't engage 4WD on the >road unless it's slippery - and when you do, you lock the front and >rear axels together - great for straight ahead traction, but virtually >impossible to steer around a corner on tarmac without producing torque >wind-up in one of your axels. Most modern systems, through the use of >automatic hubs have "Change on the fly" capability so you can engage >4WD while the vehicle is moving (an example of this is the Suzuki >Vitara and Kia Sportage). But with some, you may still have to stop or >slow down considerably to engage it. It's also important to note that >may of the safety advantages of driving a 4WD do not apply to >part-time 4WDs. This is for the reason that a 4WD system makes no >difference - unless it is engaged - which may not be the case in an >emergency situation. Why choose it? Primarily because it's simple, >less costly to build and therefore cheaper to buy. > >FULL-TIME 4WD Semantically identical to 'constant 4wd'....*unlike* the below 'permanent 4wd' (in the/our strict definition, most markedrones consider them equal, sadly) >Full-time 4WD offers a 2WD mode for normal driving, an "auto 4WD" mode >for changing conditions and a "4WD Lock" mode for the tough stuff. The >automatic aspect of this system makes it convenient for many drivers, >as the system automatically changes to 4WD when the vehicle senses the >driving conditions change. By placing some type of viscous coupling >between the front and rear axels, full-time 4WD can work >automatically, depending on driving conditions (Examples include the >Escape, Tibute, Pathfinder, X-Trail). These systems detect wheel >slippage and progressively lock the front and rear axels together to >optimise traction. But full-time 4WD, especially in the automatic >mode, still has a disadvantage off-road. On steep hills and over large >rocks, the system can shift power from axel to axel at the wrong time, >upsetting the vehilce's balance and cause a loss of traction. the >manual "lock" feature of these vehilces when fitted and engaged >overcomes this. > > >PERMANENT 4WD > >Permanent 4WD is definitely an improvemnet over full-time 4WD - it >has no 2WD mode. Becaus the vehicle is always in 4WD, you never have >to determine whether the conditions are right for 2WD or 4WD (examples >include Discovery and Freelander). On -road, permanent 4WD >automatically delivers power where it's needed with no driver action >required. Off-road you can lock the centre diff and if necessary >engage low range to maxime traction and control. The biggest >difference between Full-time and Permanent 4WD systems is that in a >permanent 4WD system all 4 wheels are driving the car at any given >stage. A slip diff (or on more modern vehicles - a viscous coupling) >between the front and rear axels stops axel wind-up on corners and can >be over-ridden by the diff lock. > > ******************* >So what's best for you? If you are planning to spend most of your time >on-road and will not encounter much extremes you might consider a part >time 4WD. Throw in some sand, rain or snow or some mountainous tracks >and the argument for a full-time or permanent 4WD system becomes >compelling. Anything above 100hp & 300Nm should have fulltime 4wd....way to easy to spin a rear tire when pulling into a busy road, on a wet street (especially with offroad tires) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "Rob2" SUBJECT: Re: Locked centre diff v traction control DATE: Fri, 24 May 2002 12:07:30 +0800 NEWSGROUPS: aus.cars.offroad Excellent description Dave. However, having now owned 2 part time (Patrol & Pajero) and 1 permanent (Landcruiser) 4WDs, personally I think the difference is overrated. If you're going offroad, you have to 'switch over' in both - button on the dash or a lever makes no real difference (though having to stop in the older part-time vehicles is a little bit of an inconvenience). The 'on-road' advantage of permanent 4wd is negligible as a vehicle as heavy as a mid to large 4WD ain't exactly a sports car, and the only practical use of permanent 4wd in 'unlocked' config may be when going up a very steep hill on a wet road or one with a bit of snow on - both scenarios not common in Oz as steep hills and snow aren't things we're over-endowed with. Both 'part-time' and 'permanent' though are both superior off road to the 'full-time' systems for the reasons you've stated. Makes you wonder why they bother. If they want to improve the on-road performance, I reckon the money would be better spent on improving the braking systems - ie- antiskid brakes (as long as you can turn the system off when you want). Rob FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 02 15:07:14 GMT NEWSGROUPS: aus.cars.offroad In article <3cedbc5e$0$3432@echo-01.iinet.net.au>, "Rob2" wrote: >Excellent description Dave. >However, having now owned 2 part time (Patrol & Pajero) and 1 permanent >(Landcruiser) 4WDs, personally I think the difference is overrated. If >you're going offroad, you have to 'switch over' in both - button on the >dash or a lever makes no real difference (though having to stop in the >older part-time vehicles is a little bit of an inconvenience). The >'on-road' advantage of permanent 4wd is negligible as a vehicle as heavy >as a mid to large 4WD ain't exactly a sports car, and the only practical >use of permanent 4wd in 'unlocked' config may be when going up a very >steep hill on a wet road or one with a bit of snow on - both scenarios >not common in Oz as steep hills and snow aren't things we're >over-endowed with. >Both 'part-time' and 'permanent' though are both superior off road to >the 'full-time' systems for the reasons you've stated. Superior?? *Inferior* A fulltime 4wd can always be switched into center-lock (if not, it doesn't belong offroad), and be equal to a (engaged) parttime 4wd). >Makes you wonder >why they bother. If they want to improve the on-road performance, I >reckon the money would be better spent on improving the braking >systems - ie- antiskid brakes (as long as you can turn the system off >when you want). Anything above 100hp & 300Nm should have fulltime 4wd, to avoid spinning a wheel on wet roads, when pulling off into a busy main road, especially with offroad tires....*very* nasty to fishtail into oncoming traffic (or not get going at all, at the speed you expected). Even on a HJ-60 I often wish I had fulltime 4wd....once drove a HJ61, and it's grunty/barking nature made me wish for fulltime 4wd even on dry roads....would be an absolute nightmare on snow/ice (a HDJ80 shows this behaviour in a milder form). -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Fri, 24 May 2002 16:57:20 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad I'm not aware that there was a permanent 4wd Landcruiser, what model was that? I do know they were and are constant 4wd. Scotty FROM: "Rob2" SUBJECT: Re: Locked centre diff v traction control DATE: Fri, 24 May 2002 19:16:06 +0800 NEWSGROUPS: aus.cars.offroad "TD4GRUNT" wrote in message news:3cede30d@news.comindico.com.au... | I'm not aware that there was a permanent 4wd Landcruiser, what model was | that? I do know they were and are constant 4wd. | Scotty Mines a '93 GXL, which is called 'Constant 4wd' by Toyota, but falls into the "Permanent" category of Dave's descriptions. I have to admit being a bit mystified by the different descriptions - how can you call something "Full-time 4WD" when it offers a 2WD mode. If you can use it in a 2WD mode, then it obviously ain't in 4WD mode "Full-time". The GXL centre diff (including when unlocked) is always sharing the driving force to both the back and front diffs. Who or what is the final word on what exactly are the correct meanings are for the terms 'Constant', 'Permanent' and 'Full-Time' 4WD. They all sound like the same thing to me - that is that the vehicle is always in 4WD and that the power is always shared in some manner between the front and rear shafts. Always = constantly, permanently and full-time. Choose your adjective. 'All Wheel Drive' on the other hand, doesn't necessarily imply that all are being at all times, it just implies that all wheels *can* be driven. It seems to be pretty well accepted that this is the term that applies to the 'reactive' 4WD systems, such as on the poor little things that get stuck with the term 'softroader'. I've seen lots of different interpretations of the terms, here and elsewhere. It'd be nice to get it sorted out once and for all. Rob FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 02 15:16:09 GMT NEWSGROUPS: aus.cars.offroad In article <3cee20c5$0$3432@echo-01.iinet.net.au>, "Rob2" wrote: >Mines a '93 GXL, which is called 'Constant 4wd' by Toyota, but falls >into the "Permanent" category of Dave's descriptions. I have to admit >being a bit mystified by the different descriptions - how can you call >something "Full-time 4WD" when it offers a 2WD mode. If you can use it >in a 2WD mode, then it obviously ain't in 4WD mode "Full-time". While it is not impossible to have '2wd' on a fulltime-/constant-4wd vehicle (Pajero/Montero & Jeep SelecTrac), it does *not* exist with Toyota. >The GXL centre diff (including when unlocked) is always sharing the >driving force to both the back and front diffs. Do you have unlocking hubs at the front? In that case you have a parttime Cruiser (like the Standard/poverty-pack models). Or someone changed the knob on your T-case handle....8-)) >Who or what is the final word on what exactly are the correct meanings >are for the terms 'Constant', 'Permanent' and 'Full-Time' 4WD. They all >sound like the same thing to me - that is that the vehicle is always in >4WD and that the power is always shared in some manner between the front >and rear shafts. Always = constantly, permanently and full-time. Choose >your adjective. Semantically it's a bit more subtle, as in 'permanently engaged' vs 'constantly driven' (= fulltime-4wd)....it *is* a stricter defintion, where 'permanent' is equal to 'reactive', not necessarily driving all wheels all the time (which *used* to be the old definition (in those days there *were* no reactive systems/couplings!)) (the VW Golf/Rabbit & Bus/Vanagon Syncro were the first in the early 80's) >'All Wheel Drive' on the other hand, doesn't necessarily imply that all >are being at all times, it just implies that all wheels *can* be driven. >It seems to be pretty well accepted that this is the term that applies >to the 'reactive' 4WD systems, such as on the poor little things that >get stuck with the term 'softroader'. > >I've seen lots of different interpretations of the terms, here and >elsewhere. It'd be nice to get it sorted out once and for all. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 2002 12:29:16 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad To make it more simple: All wheel drive: all wheels are capable of being driven Constant, Full Time, Part Time, Real Time: all of these have a lazy axle(2wd) until slip is detected (unless already chosen) and then drive is transferred to the other axle to make it 4wd.(Constantly monitored) Permanent: the name suggests it's operation, it's permanently 100% of the time in 4wd to some degree. for example: it could be a 90% front driven and 10% to the rear until the fronts slip and the percentage is then changed more towards the rear. Your Landcruiser falls in the constant 4wd group, I also believed at one stage the Landcruiser was in 4wd 100% of the time because it was called full time. Do you remember the Ford Explorer add, when it was climbing the rock sculpture, it said that it was in 2wd until slip is detected and then 4wd kicks in, in other words, Traction is "constantly" being monitored, not being driven constantly. The manufactures use these different names to confuse you and want to make you believe what the name suggests, it can be very deceiving. I hope this helps you understand a little clearer Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 02 15:19:05 GMT NEWSGROUPS: aus.cars.offroad In article <3ceef5ba@news.comindico.com.au>, "TD4GRUNT" wrote: >To make it more simple: > >All wheel drive: all wheels are capable of being driven > >Constant, Full Time, Part Time, Real Time: all of these have a lazy >axle(2wd) until slip is detected (unless already chosen) and then drive is >transferred to the other axle to make it 4wd.(Constantly monitored) Watch it! 'Real time 4wd' is a term already (ab)used by markedrones, describing a *reactive* 4wd system (on USA-SUV's I believe). >Permanent: the name suggests it's operation, it's permanently 100% of the >time in 4wd to some degree. for example: it could be a 90% front driven and >10% to the rear until the fronts slip and the percentage is then changed >more towards the rear. I wouldn't even set a lower limit....0/100 systems also exist (only ads a bit more banging while engaging, due to drivetrain-slack). >Your Landcruiser falls in the constant 4wd group, I also believed at one >stage the Landcruiser was in 4wd 100% of the time because it was called full >time. > Do you remember the Ford Explorer add, when it was climbing the rock >sculpture, it said that it was in 2wd until slip is detected and then 4wd >kicks in, in other words, Traction is "constantly" being monitored, not >being driven constantly. > >The manufactures use these different names to confuse you and want to make >you believe what the name suggests, it can be very deceiving. >I hope this helps you understand a little clearer >Scotty -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "Rob2" SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 2002 12:43:10 +0800 NEWSGROUPS: aus.cars.offroad I've gone on a little bit of a quest for knowledge. Having a read of the Toyota 'Owners Manual' revealed very little information (as expected). It did however reveal however that there was a difference in the operation of the centre diff between vehicles fitted with ABS and those that are not (which includes mine). Apparently you can't lock the centre diff in high range if you have an ABS equipped vehicle. I then had a read of my Gregory's manual (I know - I'm a cheapskate) which tells me that there's two types of transfer case - the HF2AV which has a viscous coupling, and the HF2A which doesn't. It says in the description that the selection of the diff lock in high range is deleted in the HF2AV due to the installation of the viscous coupling (which gives the diff a limited slip capability). As I can select centre diff lock in high range in my vehicle, I therefor obviously have the HF2A, which I assume (perhaps incorrectly) means that the centre diff in my transfer case operates like a normal wheel axle differential. I'm far from being a diff expert, but my understanding is that in a standard diff, with equal traction on both sides, delivers about a 60/40 torque split. Can anybody here enlighten me further, or does anybody know of a web site that can shed some more light on the operation of the Landcruiser transfer case (specifically an 80 series GXL one)? Interestingly the Gregory's manual says: "The transfer cases provide constant or full time four wheel drive in high and low range as selected......". This could be interpreted as meaning that the vehicle is EITHER in 'constant' OR 'full time' 4wd, dependent on whether the diff is locked, or it could be interpreted that the two terms are interchangeable. The Toyota owners manual calls the the 4wd system a "full-time type". Rob FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 2002 18:21:16 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad "Rob2" wrote in message news:3cef162a$0$5332@echo-01.iinet.net.au... > I've gone on a little bit of a quest for knowledge. > Having a read of the Toyota 'Owners Manual' revealed very little > information (as expected). It did however reveal however that there was > a difference in the operation of the centre diff between vehicles fitted > with ABS and those that are not (which includes mine). Apparently you > can't lock the centre diff in high range if you have an ABS equipped > vehicle. > > I then had a read of my Gregory's manual (I know - I'm a cheapskate) > which tells me that there's two types of transfer case - the HF2AV which > has a viscous coupling, and the HF2A which doesn't. It says in the > description that the selection of the diff lock in high range is deleted > in the HF2AV due to the installation of the viscous coupling (which > gives the diff a limited slip capability). > > As I can select centre diff lock in high range in my vehicle, I therefor > obviously have the HF2A, which I assume (perhaps incorrectly) means that > the centre diff in my transfer case operates like a normal wheel axle > differential. I'm far from being a diff expert, but my understanding is > that in a standard diff, with equal traction on both sides, delivers > about a 60/40 torque split. > > Can anybody here enlighten me further, or does anybody know of a web > site that can shed some more light on the operation of the Landcruiser > transfer case (specifically an 80 series GXL one)? > > Interestingly the Gregory's manual says: > "The transfer cases provide constant or full time four wheel drive in > high and low range as selected......". > This could be interpreted as meaning that the vehicle is EITHER in > 'constant' OR 'full time' 4wd, dependent on whether the diff is locked, > or it could be interpreted that the two terms are interchangeable. > The Toyota owners manual calls the the 4wd system a "full-time type". > > Rob The way I understand it Rob, and if I'm wrong someone can correct me, is if you have your diff lock on, you would be getting an equal split to front and rear 50/50, but if you have it off, you'll find that even though you have it in 4wd, only 2 wheels will be driving until slip is detected(full time4wd), unless the diff ratios are different to one another, as this tricks the VC in a sense that there is slip and delivers drive. If the diffs have the same ratio, there will be no slip developed in the VC, and thus no lock up. This is how permanent 4wd's get permanent 4wd, they develop slip in the VC to produce some drive. The more slip the more drive basically. Scotty FROM: "Rob2" SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 2002 22:06:50 +0800 NEWSGROUPS: aus.cars.offroad "TD4GRUNT" wrote in message | | The way I understand it Rob, and if I'm wrong someone can correct me, is if | you have your diff lock on, you would be getting an equal split to front and | rear 50/50, but if you have it off, you'll find that even though you have it | in 4wd, only 2 wheels will be driving until slip is detected (full time4wd), | unless the diff ratios are different to one another, as this tricks the VC | in a sense that there is slip and delivers drive. If the diffs have the same | ratio, there will be no slip developed in the VC, and thus no lock up. This | is how permanent 4wd's get permanent 4wd, they develop slip in the VC to | produce some drive. The more slip the more drive basically. | Scotty | I don't think you've got it quite right (except for the bit about with the diff lock on). Mine apparently doesn't have a viscous coupling. From what I've read, only the 80 series GXL with ABS have a viscous coupling in the CD. Looking at the breakdown of the transfer case in the book, the CD just has crown and pinion gears just like a ordinary garden variety banjo type differential. As it looks like an ordinary differential, I'd expect it to act like one. Definitely nothing high tech or 'reactive' in there. The diff lock is just what you'd expect, a splined hub that slides over the output shaft, physically locking the front and rear shafts together. The transfer case for the viscous coupling equipped versions is identical, except for the addition of the VC. This (as I understand it) should work just like a 'normal' differential, with the added benefit of 'limited slip'. It therefor makes some sense that the 'cruisers that have the VC equipped CD, don't have as much need for the diff lock, which is why it can't be engaged when in high range in those ones. My deduction is that both versions (when the CD is unlocked) are 'permanently' in 4WD' - in the same way that a HQ Kingswood is permanently in 2WD. A HQ with Salisbury limited slip diff is (in a manner of speaking) a bit more 2WD than one with a standard banjo diff. As we all know from our boy-racer years, an ordinary (non-limited slip) diff can spin one wheel in low traction conditions while the other stands still, but when both wheels have traction both wheels get a share of the torque. My conclusion is that the GXL 80 series is a 'permanent' 4WD as when all 4 wheels have traction, all 4 wheels are being driven. Obviously with the CD unlocked (in the standard CD without the VC), this isn't a very useful condition in low traction conditions - as if one of the front wheels spins, most of the torque will be lost to that one wheel (taking into account the fact that the back diff is limited slip). With the CD lock engaged, then at least one front and both back wheels will be driven. Maybe I'm missing something. Rob FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 02 15:31:08 GMT NEWSGROUPS: aus.cars.offroad In article <3cef484b@news.comindico.com.au>, "TD4GRUNT" wrote: > >"Rob2" wrote in message >news:3cef162a$0$5332@echo-01.iinet.net.au... >> I've gone on a little bit of a quest for knowledge. >> Having a read of the Toyota 'Owners Manual' revealed very little >> information (as expected). It did however reveal however that there was >> a difference in the operation of the centre diff between vehicles fitted >> with ABS and those that are not (which includes mine). Apparently you >> can't lock the centre diff in high range if you have an ABS equipped >> vehicle. >> >> I then had a read of my Gregory's manual (I know - I'm a cheapskate) >> which tells me that there's two types of transfer case - the HF2AV which >> has a viscous coupling, and the HF2A which doesn't. It says in the >> description that the selection of the diff lock in high range is deleted >> in the HF2AV due to the installation of the viscous coupling (which >> gives the diff a limited slip capability). >> >> As I can select centre diff lock in high range in my vehicle, I therefor >> obviously have the HF2A, which I assume (perhaps incorrectly) means that >> the centre diff in my transfer case operates like a normal wheel axle >> differential. I'm far from being a diff expert, but my understanding is >> that in a standard diff, with equal traction on both sides, delivers >> about a 60/40 torque split. >> >> Can anybody here enlighten me further, or does anybody know of a web >> site that can shed some more light on the operation of the Landcruiser >> transfer case (specifically an 80 series GXL one)? >> >> Interestingly the Gregory's manual says: >> "The transfer cases provide constant or full time four wheel drive in >> high and low range as selected......". >> This could be interpreted as meaning that the vehicle is EITHER in >> 'constant' OR 'full time' 4wd, dependent on whether the diff is locked, >> or it could be interpreted that the two terms are interchangeable. >> The Toyota owners manual calls the the 4wd system a "full-time type". >> >> Rob >> >> >The way I understand it Rob, and if I'm wrong someone can correct me, is if >you have your diff lock on, you would be getting an equal split to front and >rear 50/50, but if you have it off, you'll find that even though you have it >in 4wd, only 2 wheels will be driving until slip is detected(full time4wd), >unless the diff ratios are different to one another, as this tricks the VC >in a sense that there is slip and delivers drive. If the diffs have the same >ratio, there will be no slip developed in the VC, and thus no lock up. This >is how permanent 4wd's get permanent 4wd, they develop slip in the VC to >produce some drive. The more slip the more drive basically. >Scotty > You confuse 'viscous coupling' with 'viscous LSD' (on *top* of a normal geared center diff. You also reverse what happens in lock/unlock, in case of an open diff: an open diff will provide a 50/50 torque split, no matter what; but when being locked it can vary wildly, 0/100 or 100/0, depending which axle is airborn....since an airborn wheel has no traction (only rotational inertia and some internal friction), there is also no torque (nor power, as power is basically torque x rpm)....and all torque goes to the grip-wheels (until they start spinning to; that's the maximum level of torque that can be transferred, regardless whether the engine can supply more). 80-series Land Cruisers 93-98 have a viscous *LSD*, category '30%', according to Toyota; implying that in a worst-case scenario, a maximum of 30% of available engine torque is supplied to the slipping axle, in 1st-gear high-range (which means the bias gets better at higher gears!)....in low-range the normal mechanical diff-lock is engaged anyway. Further: you can modify this system, by disengaging the default lock in low range (pulling a plug just above the T-case), but with the models '93-98 you must then also add a manual diff-lock button (as it didn't have one for high-range; that's what the visco-LSD was for (to allow ABS to work!)). -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: prometheus_au@excite.com.au (Dave) SUBJECT: Re: Locked centre diff v traction control DATE: 24 May 2002 06:25:32 -0700 ORGANIZATION: http://groups.google.com/ NEWSGROUPS: aus.cars.offroad jimf@DELETEME.pobox.com (Jim (from Oz)) wrote in message news:<3cedceea.29824781@mel-news.tpg.com.au>... > On 23 May 2002 19:42:00 -0700, prometheus_au@excite.com.au (Dave) > wrote: > > >Definitions of 4WD Systems... > > Thanks for that Dave, a very good description. > > >So what's best for you? If you are planning to spend most of your time > >on-road and will not encounter much extremes you might consider a part > >time 4WD. Throw in some sand, rain or snow or some mountainous tracks > >and the argument for a full-time or permanent 4WD system becomes > >compelling. > > Now this is where you lost me :) Surely a part time 4WD (with 4WD > engaged) is just the same as a permanent 4WD. Agreed you can > only put a part time vehicle into 4WD in off road conditions but that > is the main (only? in Oz) place I want it. Have I missed a point you > were making? > > Jim (from Oz) Jim, :) You're totally correct - off road a part-time 4WD in lock will act similarly to a Full-Time or Permanent 4WD in lock mode. Depending on of course design alterations that manufacturers add or remove. The differences become apparent on-road where in a Part-time 4WD encountering slippery conditions may not be able to engage 4WD until it's too late, whereas a Full-time 4WD will have detected the wheel slip and compensated or in a Permanent 4WD all 4 wheels would be driving amnyways so there's no need to really do much. Again the obverse is true when in dry conditions on-road a Part-time 4WD cannot be locked up to use all 4 wheels because of axel wind-up going around corners; where as the full-time 4WD will lock as required and compensate for axel wind up through the viscous coupling & the Permanent 4WD is allways driving 4 wheels and makes up for wind-up via again a viscous coupling or centre slip diff. (and I can take a breath here).... The point here is mainly - what level of user friendlyness do you want. If stopping before a track and engaging 4WD isn't a problem fine, if you want to be able to do it on the fly or have a viscous coupling do it for you, then the next level is probably better. If you're lazy as all heck (that was a joke) or you like the fact that when you're on the road - any road - 4 wheels are always driving, and you can afford the bugger then the next level again is for you. My definition above is not meant to belittle any one system. It's all in the eye of the driver. It was meant to differentiate how the systems work and how they operate. I personally own an Escape which fits into the middle category. I've driven my car, Discovery's, Range Rovers, Freelanders and Suzuki's off-road and all perform (in relation to what they're designed for) extremely well. The problem with the different systems and vehicles becomes apparent when people start comparing a Suzuki XL7 to a Discovery or Land Cruiser.... compare apples with apples.... cheers Dave. FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Fri, 24 May 2002 17:10:57 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > Now this is where you lost me :) Surely a part time 4WD (with 4WD > engaged) is just the same as a permanent 4WD. Agreed you can > only put a part time vehicle into 4WD in off road conditions but that > is the main (only? in Oz) place I want it. Have I missed a point you > were making? > > Jim (from Oz) > > -- > Speed doesn't kill - bad driving kills It depends on the system it's running, for example, Honda's CRV's are woffle, because they rely on the front wheels to pump hydraulic fluid to a clutch pack in the rear diff when there is slip detected, and it's a matter of shut the gate after the horse has bolted. There are other types where you engage 4wd, they should only be used on a surface that is slippery so that the drivetrain doesn't wind itself up, this is the difference with permanent, it has the VC to prevent wind up. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 02 15:39:49 GMT NEWSGROUPS: aus.cars.offroad In article <526e114e.0205240525.653a7aca@posting.google.com>, prometheus_au@excite.com.au (Dave) wrote: >jimf@DELETEME.pobox.com (Jim (from Oz)) wrote in message news:<3cedceea.29824781@mel-news.tpg.com.au>... >> On 23 May 2002 19:42:00 -0700, prometheus_au@excite.com.au (Dave) >> wrote: >> >> >Definitions of 4WD Systems... >> Thanks for that Dave, a very good description. >> >> >So what's best for you? If you are planning to spend most of your time >> >on-road and will not encounter much extremes you might consider a part >> >time 4WD. Throw in some sand, rain or snow or some mountainous tracks >> >and the argument for a full-time or permanent 4WD system becomes >> >compelling. >> >> Now this is where you lost me :) Surely a part time 4WD (with 4WD >> engaged) is just the same as a permanent 4WD. Agreed you can >> only put a part time vehicle into 4WD in off road conditions but that >> is the main (only? in Oz) place I want it. Have I missed a point you >> were making? >> >> Jim (from Oz) > >Jim, > >:) You're totally correct - off road a part-time 4WD in lock will act >similarly to a Full-Time or Permanent 4WD in lock mode. Depending on >of course design alterations that manufacturers add or remove. The >differences become apparent on-road where in a Part-time 4WD >encountering slippery conditions may not be able to engage 4WD until >it's too late, whereas a Full-time 4WD will have detected the wheel >slip and compensated or in a Permanent 4WD all 4 wheels would be >driving amnyways so there's no need to really do much. With the added note that locking a fulltime-4wd can improve onroad-handling dramatically, when facing irregular patches of snow/slush....leaving the center diff open means that individual wheels can and will spin, and jerk in the steering wheel when they hit dry road again....locking the center diff makes it amazingly more stable. >Again the >obverse is true when in dry conditions on-road a Part-time 4WD cannot >be locked up to use all 4 wheels because of axel wind-up going around >corners; where as the full-time 4WD will lock as required and >compensate for axel wind up through the viscous coupling & the >Permanent 4WD is allways driving 4 wheels and makes up for wind-up via >again a viscous coupling or centre slip diff. (and I can take a breath >here).... I would not call it a center (slip) 'diff' in a permanent(reactive) 4wd....I would keep the term 'diff' for a true geared unit. (my strict definition of a true diff is that it allows rpm differences *while* not interfering with torque distribution *due* to rpm differences....this excludes *all* reactive couplings/systems) (and even excludes viscous LSD's on top of a normal diff, but those mostly don't react to onroad/corner rpm differences (unlike most viscous couplings!)) >The point here is mainly - what level of user friendlyness do you >want. If stopping before a track and engaging 4WD isn't a problem >fine, if you want to be able to do it on the fly or have a viscous >coupling do it for you, then the next level is probably better. If >you're lazy as all heck (that was a joke) or you like the fact that >when you're on the road - any road - 4 wheels are always driving, and >you can afford the bugger then the next level again is for you. > >My definition above is not meant to belittle any one system. It's all >in the eye of the driver. It was meant to differentiate how the >systems work and how they operate. I personally own an Escape which >fits into the middle category. I've driven my car, Discovery's, Range >Rovers, Freelanders and Suzuki's off-road and all perform (in relation >to what they're designed for) extremely well. The problem with the >different systems and vehicles becomes apparent when people start >comparing a Suzuki XL7 to a Discovery or Land Cruiser.... compare >apples with apples.... > >cheers >Dave. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sat, 25 May 02 15:44:15 GMT NEWSGROUPS: aus.cars.offroad In article <526e114e.0205240525.652d0389@posting.google.com>, prometheus_au@excite.com.au (Dave) wrote: >jimf@DELETEME.pobox.com (Jim (from Oz)) wrote in message news:<3cedceea.29824781@mel-news.tpg.com.au>... >> On 23 May 2002 19:42:00 -0700, prometheus_au@excite.com.au (Dave) >> wrote: >> >> >Definitions of 4WD Systems... >> Thanks for that Dave, a very good description. >> >> >So what's best for you? If you are planning to spend most of your time >> >on-road and will not encounter much extremes you might consider a part >> >time 4WD. Throw in some sand, rain or snow or some mountainous tracks >> >and the argument for a full-time or permanent 4WD system becomes >> >compelling. >> >> Now this is where you lost me :) Surely a part time 4WD (with 4WD >> engaged) is just the same as a permanent 4WD. Agreed you can >> only put a part time vehicle into 4WD in off road conditions but that >> is the main (only? in Oz) place I want it. Have I missed a point you >> were making? >> >> Jim (from Oz) > >Jim, > >:) You're totally correct - off road a part-time 4WD in lock will act >similarly to a Full-Time or Permanent 4WD in lock mode. Depending on >of course design alterations that manufacturers add or remove. The >differences become apparent on-road where in a Part-time 4WD >encountering slippery conditions may not be able to engage 4WD until >it's too late, whereas a Full-time 4WD will have detected the wheel >slip and compensated or in a Permanent 4WD all 4 wheels would be >driving amnyways so there's no need to really do much. I think you now reverse the two again: a fulltime-4wd doesn't detect anything (unless it has an additional center-LSD or electronics), while it is the 'permanent' category that must detect before it can be engaged....that's it's very 'reactive' nature: engaging 4wd only *when*, *after* and _as long as_ slip occurs....and this is what can be way too late in a slippery & fast driven corner....spreading torque 25/25/25/25 over each wheel is much better than 0/0/50/50.... -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "Rob2" SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 2002 02:08:08 +0800 NEWSGROUPS: aus.cars.offroad "Willem-Jan Markerink" wrote in message news:aco9o2$raj28$5@ID-34205.news.dfncis.de... | In article <3cee20c5$0$3432@echo-01.iinet.net.au>, | "Rob2" wrote: | >Mines a '93 GXL, which is called 'Constant 4wd' by Toyota, but falls | >into the "Permanent" category of Dave's descriptions. I have to admit | >being a bit mystified by the different descriptions - how can you call | >something "Full-time 4WD" when it offers a 2WD mode. If you can use it | >in a 2WD mode, then it obviously ain't in 4WD mode "Full-time". | | While it is not impossible to have '2wd' on a fulltime-/constant-4wd vehicle | (Pajero/Montero & Jeep SelecTrac), it does *not* exist with Toyota. Didn't say it did. I was refering to Dave's version of 'full-time'. | >The GXL centre diff (including when unlocked) is always sharing the | >driving force to both the back and front diffs. | | Do you have unlocking hubs at the front? | In that case you have a parttime Cruiser (like the Standard/poverty-pack | models). | Or someone changed the knob on your T-case handle....8-)) Sorry - should have added the words "... when all wheels have traction." to that sentence. Rob FROM: "Rob2" SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 2002 03:14:20 +0800 NEWSGROUPS: aus.cars.offroad "Willem-Jan Markerink" wrote in message | Superior?? | *Inferior* | A fulltime 4wd can always be switched into center-lock (if not, it doesn't | belong offroad), and be equal to a (engaged) parttime 4wd). Once again I was using Dave's version of the term 'full-time'. I think I'm getting the terms under control now. Here's the versions I'm starting to put together in my head after this peripatetic thread: PART-TIME 4WD As per Dave's description. Simple and reliable. A transfer case which can be engaged or disengaged - if disengaged drives only one tail shaft, if engaged drives both CONSTANT &/or FULL-TIME As per Dave's previous description of 'Permanent'. A centre differential, which may or may not have some form of limited slip capability, driving both front and rear shafts *all* of the time. ALL WHEEL DRIVE A reactive/automatic system which may or may not be able to be be overidden by selection. PERMANENT This is the curly one. I reckon this should really be used only for Constant/Full-time systems, but is often used to describe both them, as well as *some* of the All Wheel Drive systems. This is the one you'd probably use if you're a salesman trying to flog something that isn't really a constant 4WD and are a bit embarrassed about it. :) Then again - all of the above is subject to marketing disinformation. The vehicle really needs to be described by the particular system on the vehicle to have any hope of knowing what it's really doing. I really don't think the reactive 4WD systems which only engage 4WD after sensing a loss of traction should be called Constant, Full-time OR Permanent 4WD, as it's plainly none of those things. Rob FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 02 00:33:51 GMT NEWSGROUPS: aus.cars.offroad In article <3cefe256$0$5329@echo-01.iinet.net.au>, "Rob2" wrote: > >"Willem-Jan Markerink" wrote in message >| Superior?? >| *Inferior* >| A fulltime 4wd can always be switched into center-lock (if not, it doesn't >| belong offroad), and be equal to a (engaged) parttime 4wd). > >Once again I was using Dave's version of the term 'full-time'. >I think I'm getting the terms under control now. Here's the versions I'm >starting to put together in my head after this peripatetic thread: > >PART-TIME 4WD >As per Dave's description. Simple and reliable. Well, yes and no. *If* parttime fails, you are stuck in 2wd (stuck in 4wd is also possible, but less common I believe)....this applies in particular to electric- or vacuum-actuated T-cases. A fulltime-4wd system would still be in 4wd, although with an open diff....but that's not nearly as bad as being stuck in 2wd....:)) >A transfer case which >can be engaged or disengaged - if disengaged drives only one tail shaft, >if engaged drives both > >CONSTANT &/or FULL-TIME >As per Dave's previous description of 'Permanent'. A centre differential, >which may or may not have some form of limited slip capability, driving >both front and rear shafts *all* of the time. > >ALL WHEEL DRIVE >A reactive/automatic system which may or may not be able to be be >overidden by selection. > >PERMANENT >This is the curly one. I reckon this should really be used only for >Constant/Full-time systems, but is often used to describe both them, as >well as *some* of the All Wheel Drive systems. This is the one you'd >probably use if you're a salesman trying to flog something that isn't >really a constant 4WD and are a bit embarrassed about it. >:) > >Then again - all of the above is subject to marketing disinformation. The >vehicle really needs to be described by the particular system on the >vehicle to have any hope of knowing what it's really doing. I really >don't think the reactive 4WD systems which only engage 4WD after sensing a >loss of traction should be called Constant, Full-time OR Permanent 4WD, as >it's plainly none of those things. Well, 'permanently engaged' is still semantically correct....'constantly engaged' sounds much worse.... -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 2002 11:07:59 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad "> > PERMANENT > This is the curly one. I reckon this should really be used only for > Constant/Full-time systems, but is often used to describe both them, as > well as *some* of the All Wheel Drive systems. This is the one you'd > probably use if you're a salesman trying to flog something that isn't > really a constant 4WD and are a bit embarrassed about it. > :) My Freelander is a permanent 4wd, and listening to this bull about slip before drive when it too late, is total crap. How do you explain if it wasn't a permanent 4wd, from a standing start, how I can put my front wheels in loose gravel and the rears on firm ground, floor it, and the front wheels don't slip? This to me proves it's in 4wd permanently. So it's not a term that is just made up and to be embarrassed about, but a term that actually works that way. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 02 11:37:25 GMT NEWSGROUPS: aus.cars.offroad In article <3cf03427@news.comindico.com.au>, "TD4GRUNT" wrote: > >"> >> PERMANENT >> This is the curly one. I reckon this should really be used only for >> Constant/Full-time systems, but is often used to describe both them, as >> well as *some* of the All Wheel Drive systems. This is the one you'd >> probably use if you're a salesman trying to flog something that isn't >> really a constant 4WD and are a bit embarrassed about it. >> :) >> > > >My Freelander is a permanent 4wd, and listening to this bull about slip >before drive when it too late, is total crap. How do you explain if it >wasn't a permanent 4wd, from a standing start, how I can put my front wheels >in loose gravel and the rears on firm ground, floor it, and the front wheels >don't slip? This to me proves it's in 4wd permanently. So it's not a term >that is just made up and to be embarrassed about, but a term that actually >works that way. >Scotty If you can't spin all 4 wheels on gravel, you don't have enough power....;)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 02 11:59:22 GMT NEWSGROUPS: aus.cars.offroad In article , w.j.markerink@a1.nl (Willem-Jan Markerink) wrote: >If you can't spin all 4 wheels on gravel, you don't have enough power....;)) Or not enough difflocks of course....:)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "Rob2" SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 2002 15:36:36 +0800 NEWSGROUPS: aus.cars.offroad "TD4GRUNT" wrote in message news:3cf03427@news.comindico.com.au... | | > PERMANENT | > This is the curly one. I reckon this should really be used only for | > Constant/Full-time systems, but is often used to describe both them,as | > well as *some* of the All Wheel Drive systems. This is the one you'd | > probably use if you're a salesman trying to flog something that isn't | > really a constant 4WD and are a bit embarrassed about it. | > :) | > | | | My Freelander is a permanent 4wd, and listening to this bull about slip | before drive when it too late, is total crap. How do you explain if it | wasn't a permanent 4wd, from a standing start, how I can put my front wheels | in loose gravel and the rears on firm ground, floor it, and the front wheels | don't slip? This to me proves it's in 4wd permanently. So it's not a term | that is just made up and to be embarrassed about, but a term that actually | works that way. | Scotty | Don't know anything about the Freelander, and it may be a great system, but if it's normally in 2WD and only engages 4WD when it detects slip, then I think calling it a 'Permanent 4WD' system is handling the truth a bit carelessly. 'Automatic 4WD' or 'Reactive 4WD' system' would be more descriptive, and would save us poor chaps from being confused (and I know I am). Being called a reactive, automatic or all wheel drive system shouldn't necessarily be derogatory. I haven't tried your 'front wheels on gravel' scenario, but if I tried that in my 80 (with the centre diff unlocked) I imagine that at least one of my front wheels would probably spin. With the diff locked, or if I had the version with the viscous coupling, it obviously wouldn't. Horses for courses. From what I've seen and read, some of the reactive systems are very good, some aren't. Some sacrifice some offroad ability for onroad handling or to save a few $$. Some are designed with the snow and ice on North American winter roads in mind, and aren't of much use in Australian conditions. I remember a trip along some muddy NW WA tracks with us in our part-time Pajero, and our friends in their Quadratrak equipped Cherokee. We were just driving along with no fuss, and they were slipping all over the road (and into the ditch a couple of times). The important thing is to understand the pros and cons of the system fitted to the vehicle you have. I reckon having the system described in terms that are truly descriptive would help in this regard. Rob FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 2002 11:32:13 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad "> I think you now reverse the two again: a fulltime-4wd doesn't detect anything > (unless it has an additional center-LSD or electronics), while it is the > 'permanent' category that must detect before it can be engaged....that's it's > very 'reactive' nature: engaging 4wd only *when*, *after* and _as long as_ slip > occurs....and this is what can be way too late in a slippery & fast driven > corner....spreading torque 25/25/25/25 over each wheel is much better than > 0/0/50/50.... This is where you contradict yourself, if it engages "when, after, and as long as slip occurs", what is there to engage when it is permanently engaged? The only thing that happens is, the percentage of slip(when it does) is transferred to the other axle. Why would a full time spread torque 25/25/25/25 and a permanent or part time wouldn't? The transfer case only spread the torque between the front and rear axles, not the individual wheel. It's the job of the diff that determines what each wheel gets, and then LSD can only tolerate so much torque (90nm+-)before letting go, and then your getting 0/0/50/50. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 02 11:52:18 GMT NEWSGROUPS: aus.cars.offroad In article <3cf039d4@news.comindico.com.au>, "TD4GRUNT" wrote: > >"> I think you now reverse the two again: a fulltime-4wd doesn't detect anything >> (unless it has an additional center-LSD or electronics), while it is the >> 'permanent' category that must detect before it can be engaged....that's it's >> very 'reactive' nature: engaging 4wd only *when*, *after* and _as long as_slip >> occurs....and this is what can be way too late in a slippery & fast driven >> corner....spreading torque 25/25/25/25 over each wheel is much better than >> 0/0/50/50.... > >This is where you contradict yourself, if it engages "when, after, and as >long as slip occurs", what is there to engage when it is permanently >engaged? It is engaged in the sense that you don't have to pull another lever to have 4wd *available*.... Or perhaps better: can be *left* permanently engaged, without binding onroad (you could say this is already done at the factory, without user control, but some systems switching between pure 2wd and reactive-4wd (mostly the electronic kind); however, this 'pure 2wd' option doesn't exist among the viscous-clutch category AFAIK, so 'left engaged this way at the factory' would apply here). >The only thing that happens is, the percentage of slip(when it >does) is transferred to the other axle. >Why would a full time spread torque 25/25/25/25 and a permanent or part time >wouldn't? Because fulltime is *always* 25/25/25/25 (all diff's open), while permanent/reactive starts off around 0/0/50/50 (or 50/50/0/0 in case of FWD-based/engined models, and perhaps slightly higher numbers than '0' in case of viscous clutches (but hardly ever with electric clutches)); and part-time (switched into 4wd of course) varies wildly by definition, just like a locked center diff would in a fulltime. >The transfer case only spread the torque between the front and >rear axles, not the individual wheel. It's the job of the diff that >determines what each wheel gets, and then LSD can only tolerate so much >torque (90nm+-)before letting go, and then your getting 0/0/50/50. >Scotty Only with one wheel airborn (or axle in case of LSD on center diff), otherwise you will always have something higher than 0%. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 2002 12:27:59 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > PERMANENT > This is the curly one. I reckon this should really be used only for > Constant/Full-time systems, but is often used to describe both them, as > well as *some* of the All Wheel Drive systems. This is the one you'd > probably use if you're a salesman trying to flog something that isn't > really a constant 4WD and are a bit embarrassed about it. Rob, my freelander falls into this category, and it is a constant, full time, whatever you want to call it, 4wd, it's permanently in 4wd 100% of the time(nothing to turn it on or off), so how do you explain that it's not really a constant (permanent) 4wd? Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Sun, 26 May 02 11:56:58 GMT NEWSGROUPS: aus.cars.offroad In article <3cf046e6$1@news.comindico.com.au>, "TD4GRUNT" wrote: >> PERMANENT >> This is the curly one. I reckon this should really be used only for >> Constant/Full-time systems, but is often used to describe both them, as >> well as *some* of the All Wheel Drive systems. This is the one you'd >> probably use if you're a salesman trying to flog something that isn't >> really a constant 4WD and are a bit embarrassed about it. > > >Rob, my freelander falls into this category, and it is a constant, full >time, whatever you want to call it, 4wd, it's permanently in 4wd 100% of >the time(nothing to turn it on or off), so how do you explain that it's not >really a constant (permanent) 4wd? >Scotty Because it does *not* drive _all the wheels_, _all the time_, with any *significant* percentage of torque (the 5 or 10% is a threshold to overcome drive-train slop). Your system might be more fast/firm than old viscous systems, but it is still only significantly engaging *when*, *after*, and _as long as_ slip occurs. On very delicate surfaces like sand and ice, this is *not* good....any wheelspin, be it before or during 4wd, should be avoided like the plague. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 2002 09:02:37 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > Don't know anything about the Freelander, and it may be a great system, > but if it's normally in 2WD and only engages 4WD when it detects slip, > then I think calling it a 'Permanent 4WD' system is handling the truth a > bit carelessly. This is the point I'm making! It's never in 2wd... NEVER!, ALWAYS, PERMANENTLY, CONSTANTLY,FULLTIME, 100% in 4wd, and yet people say it's automatic part time....part time?? How could it be when it's drive is split 90/10 until slip and then the percentage changes more to the rear. This is achieved by having the diff ratios different, which causes the VC to lock a little and produce drive to the rear always. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 02 01:07:15 GMT NEWSGROUPS: aus.cars.offroad In article <3cf16846@news.comindico.com.au>, "TD4GRUNT" wrote: > >> Don't know anything about the Freelander, and it may be a great system, >> but if it's normally in 2WD and only engages 4WD when it detects slip, >> then I think calling it a 'Permanent 4WD' system is handling the truth a >> bit carelessly. > > >This is the point I'm making! It's never in 2wd... NEVER!, ALWAYS, >PERMANENTLY, CONSTANTLY,FULLTIME, 100% in 4wd, and yet people say it's >automatic part time....part time?? How could it be when it's drive is split >90/10 until slip and then the percentage changes more to the rear. This is >achieved by having the diff ratios different, which causes the VC to lock a >little and produce drive to the rear always. >Scotty Just enough power to overcome the drag of the wheels itself is not my definition of 'driving wheels', but 'driven wheels'....;)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 2002 09:04:18 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad "Willem-Jan Markerink" wrote in message news:acqha3$rkc54$3@ID-34205.news.dfncis.de... > In article <3cf03427@news.comindico.com.au>, > "TD4GRUNT" wrote: > > > >"> > >> PERMANENT > >> This is the curly one. I reckon this should really be used only for > >> Constant/Full-time systems, but is often used to describe both them, as > >> well as *some* of the All Wheel Drive systems. This is the one you'd > >> probably use if you're a salesman trying to flog something that isn't > >> really a constant 4WD and are a bit embarrassed about it. > >> :) > >> > > > > > >My Freelander is a permanent 4wd, and listening to this bull about slip > >before drive when it too late, is total crap. How do you explain if it > >wasn't a permanent 4wd, from a standing start, how I can put my front wheels > >in loose gravel and the rears on firm ground, floor it, and the front wheels > >don't slip? This to me proves it's in 4wd permanently. So it's not a term > >that is just made up and to be embarrassed about, but a term that actually > >works that way. > >Scotty > > If you can't spin all 4 wheels on gravel, you don't have enough power....;)) > > > -- Did I say I had my 4 wheels on gravel...NO!! I said the rears on FIRM GROUND. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 02 01:22:04 GMT NEWSGROUPS: aus.cars.offroad In article <3cf168aa$1@news.comindico.com.au>, "TD4GRUNT" wrote: > >"Willem-Jan Markerink" wrote in message >news:acqha3$rkc54$3@ID-34205.news.dfncis.de... >> In article <3cf03427@news.comindico.com.au>, >> "TD4GRUNT" wrote: >> > >> >"> >> >> PERMANENT >> >> This is the curly one. I reckon this should really be used only for >> >> Constant/Full-time systems, but is often used to describe both them, as >> >> well as *some* of the All Wheel Drive systems. This is the one you'd >> >> probably use if you're a salesman trying to flog something that isn't >> >> really a constant 4WD and are a bit embarrassed about it. >> >> :) >> >> >> > >> > >> >My Freelander is a permanent 4wd, and listening to this bull about slip >> >before drive when it too late, is total crap. How do you explain if it >> >wasn't a permanent 4wd, from a standing start, how I can put my front wheels >> >in loose gravel and the rears on firm ground, floor it, and the front wheels >> >don't slip? This to me proves it's in 4wd permanently. So it's not a term >> >that is just made up and to be embarrassed about, but a term that actually >> >works that way. >> >Scotty >> >> If you can't spin all 4 wheels on gravel, you don't have enough >power....;)) >> >> >> -- >Did I say I had my 4 wheels on gravel...NO!! I said the rears on FIRM >GROUND. You can stand on your head if you want, but the only system capable of biasing torque the very moment it slips is a torsen....anything else will have to detect slip first in a rotational sense, and the only way to do that is by 'allowing' slip in the first place; then engage, release after a while, see whether there still is slip, and engage again if needed, ad infinitum. Your front tires *must* spin before the system can react.... (and the obvious designers preference for a very quick reaction (very little rpm-differences needed) vs a delayed one is countered by the fact that a very quick system will also bind in tight corners, which will *cause* slip on ice....you can't have it both ways) Your 90/10 system is no different than that of the Jeep Quadratrak-II (JGC, 10/90), or the Subaru auto's of earlier models (90/10), and those are *not* as stable in fast driven corners as their 50/50 counterparts.... Read this to understand the difference: http://www.a1.nl/phomepag/markerink/quadrive.htm Now please don't be mad at us....just buy a true fulltime with your next vehicle....;)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 2002 09:20:51 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > >> > Because it does *not* drive _all the wheels_, _all the time_, with any > *significant* percentage of torque (the 5 or 10% is a threshold to overcome > drive-train slop). Bullshit, it is never in 2wd, in fact they warn you about putting it on a single drive dyno and it must be on a double roller because it's a permanent ,constant, whatever you see fit, 4wd. Have you ever driven a Freelander?, I would say not, you've been suck in that Landcruiser that you reckon you can out drag cars towing 3 ton behind you and do 180km/h manoeuvres, I find it very hard to believe and very foolish. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 02 01:28:01 GMT NEWSGROUPS: aus.cars.offroad In article <3cf16c8c@news.comindico.com.au>, "TD4GRUNT" wrote: > >> >> >> Because it does *not* drive _all the wheels_, _all the time_, with any >> *significant* percentage of torque (the 5 or 10% is a threshold to overcome >> drive-train slop). > >Bullshit, it is never in 2wd, in fact they warn you about putting it on a >single drive dyno and it must be on a double roller because it's a permanent >,constant, whatever you see fit, 4wd. Of course they say that, otherwise the rear axle will engage, as it senses rpm differences between front and rear, and will push off the dyno....8-)) >Have you ever driven a Freelander?, I would say not, you've been suck in >that Landcruiser that you reckon you can out drag cars towing 3 ton behind >you and do 180km/h manoeuvres, I find it very hard to believe and very >foolish. Some other fools drive 250km/h with them, or even 300km/h....:)) http://www.a1.nl/phomepag/markerink/80speed.txt Btw, it was 3500kg, and I never went over 130km/h with that combo....even though the trailer was stable enough for that, and the Cruiser all to eager to push further, I considered that the boat on top wasn't designed for such a constant tornado....:)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 2002 17:50:21 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > Of course they say that, otherwise the rear axle will engage, as it senses rpm > differences between front and rear, and will push off the dyno....8-)) I realised after sending it that this was a bad example, I was trying to give an example that the rear wheels aren't lazy until massive slip is detected, but they are actually being driven to drive the car under normal driving conditions. Scotty > Btw, it was 3500kg, and I never went over 130km/h with that combo....even though > the trailer was stable enough for that, and the Cruiser all to eager to > push further, I considered that the boat on top wasn't designed for such a > constant tornado....:)) Yours must be heavily worked to achieve this, because I towed a 1ton+ camper trailer to Cairns, and was passing diesel Landcruiser towing simular weights up hills. And yes... they were trying...belching out the black smoke. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 02 20:45:04 GMT NEWSGROUPS: aus.cars.offroad In article <3cf1e3fb$1@news.comindico.com.au>, "TD4GRUNT" wrote: > >> >> Of course they say that, otherwise the rear axle will engage, as it senses rpm >> differences between front and rear, and will push off the dyno....8-)) >> > >I realised after sending it that this was a bad example, I was trying to >give an example that the rear wheels aren't lazy until massive slip is >detected, but they are actually being driven to drive the car under normal >driving conditions. No, only to drive the wheels itself....;)) >> Btw, it was 3500kg, and I never went over 130km/h with that combo....even >though >> the trailer was stable enough for that, and the Cruiser all to eager to >> push further, I considered that the boat on top wasn't designed for such a >> constant tornado....:)) > >Yours must be heavily worked to achieve this, because I towed a 1ton+ camper >trailer to Cairns, and was passing diesel Landcruiser towing simular weights >up hills. And yes... they were trying...belching out the black smoke. No TDi should be without fullsize intercooler + larger exhaust + snorkel (albeit the latter didn't add much; yet still mandatory at Aussie outfitters)....I consider those more upgrades than modifications. Maximum tweaking (engine surgery, pistons/injectors) would have added another 33% of power & torque (300hp/700Nm)....yet surprisingly enough that's also what Yanmar makes from the same engine with an water/water intercooler, 'stock'....which gives a nice impression of it's mechanical stability. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 2002 16:31:39 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad I'm not disputing that something with a transfer case,centre diff lock, locked diffs and all that good stuff is stronger and better in the bush, in fact I don't really care, because I didn't buy a Freelander to do any really serious rock hopping off roading, but at the same time, it's not as bad(inferior) off road as you make out. In fact a lot of ppl are surprised at 4wd meetings, how well they do off road and get through mud and slippery obstacles better than their bigger brothers. This is a comment from a 4wd meeting. "The course, approximately three miles, was challenging yet fun. There were several mud holes - some very deep- steep hills, ditches to cross, and steep curbs. The traction control and handling of the Freelander was superb! Perhaps the greatest shock was that of the Discovery, Defender, and Range Rover owners. They could not believe the abilities of the Freebie. It actually out-performed the Discoverys climbing hills and pulling out of muddy holes! Of course, the Discos greater ground clearance made it a bit easier for them crossing ditches. There were between 8 to 10 Freelanders on the track throughout the day. Most drivers drove the course three or four times. None of the Freelanders got stuck! At least 10 Discoverys were pulled out of deep muddy holes. I watched three being pulled out of one hole and then proceeded to drive through it with no problems. My vehicle did not fortunately, slide into the deepest part. One of the most helpful things that I learned was to give the little Rover just a few seconds longer for the traction control to take charge. When I thought that I was stuck for the first time, my dealer told me to keep giving it a steady amount of gas and it will pull out. It did so without any hesitation. I was to say the least, overwhelmed with the power and abilities of the traction control! My Freelander survived the day without any damage or scratches". http://www.freelanderowners.com/Gallery.asp And this is a comment from a car review, http://www.newcartestdrive.com/review-intro.cfm?ReviewID=1164 "Technically, the new Land Rover Freelander doesn't match the off-road capability of the bigger Discovery or of the expensive Range Rover. In reality, though, it will go much farther into the backcountry than most anyone will want to go. *Equipped with permanent all-wheel drive*, traction control, Hill Descent Control, and a surprisingly capable suspension, the Freelander easily surpasses the capability of the Ford Escape, Toyota RAV4, Honda CR-V and other so-called cute-utes. For practical purposes, the Freelander matches the off-roadworthiness of the impressive Jeep Liberty". You may say that the back wheels just turn enough to not get dragged along, but let me tell you, it is more than that, I have not had the front wheels spin (on road) where you would expect them to. For example, there is a intersection near me, and it's on hill, in the rain it becomes extremely slippery, in my previous car (Falcon with LSD) with only light acceleration, it used to fish tail out, a 1200cc Corolla could do it. This intersection is notorious for this, so I tested it out one day, and I tried hard, but no spin, so what I'm saying is, there is more drive from the back wheels than you think. Don't get it confused with "Real Time", (more like "unreal time") now this is a system that is a case of shut the gate after the horse has bolted. You should do yourself a favour and drive a Freelander before you shoot your mouth off and experience what sort of traction is achieved. Scotty P.S just to confuse things even more, I have noticed that Renault now has "constant real time", there getting better and better at confusing ppl...LOL FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 02 21:04:21 GMT NEWSGROUPS: aus.cars.offroad In article <3cf1d187@news.comindico.com.au>, "TD4GRUNT" wrote: >I'm not disputing that something with a transfer case,centre diff lock, >locked diffs and all that good stuff is stronger and better in the bush, in >fact I don't really care, because I didn't buy a Freelander to do any really >serious rock hopping off roading, but at the same time, it's not as >bad(inferior) off road as you make out. In fact a lot of ppl are surprised >at 4wd meetings, how well they do off road and get through mud and slippery >obstacles better than their bigger brothers. This is a comment from a 4wd >meeting. > >"The course, approximately three miles, was challenging yet fun. There were >several mud holes - some very deep- steep hills, ditches to cross, and steep >curbs. The traction control and handling of the Freelander was superb! >Perhaps the greatest shock was that of the Discovery, Defender, and Range >Rover owners. They could not believe the abilities of the Freebie. It >actually out-performed the Discoverys climbing hills and pulling out of >muddy holes! Of course, the Discos greater ground clearance made it a bit >easier for them crossing ditches. There were between 8 to 10 Freelanders on >the track throughout the day. Most drivers drove the course three or four >times. None of the Freelanders got stuck! At least 10 Discoverys were pulled >out of deep muddy holes. I watched three being pulled out of one hole and >then proceeded to drive through it with no problems. My vehicle did not >fortunately, slide into the deepest part. One of the most helpful things >that I learned was to give the little Rover just a few seconds longer for >the traction control to take charge. When I thought that I was stuck for the >first time, my dealer told me to keep giving it a steady amount of gas and >it will pull out. It did so without any hesitation. I was to say the least, >overwhelmed with the power and abilities of the traction control! My >Freelander survived the day without any damage or scratches". >http://www.freelanderowners.com/Gallery.asp > > >And this is a comment from a car review, >http://www.newcartestdrive.com/review-intro.cfm?ReviewID=1164 > >"Technically, the new Land Rover Freelander doesn't match the off-road >capability of the bigger Discovery or of the expensive Range Rover. In >reality, though, it will go much farther into the backcountry than most >anyone will want to go. *Equipped with permanent all-wheel drive*, traction >control, Hill Descent Control, and a surprisingly capable suspension, the >Freelander easily surpasses the capability of the Ford Escape, Toyota RAV4, >Honda CR-V and other so-called cute-utes. For practical purposes, the >Freelander matches the off-roadworthiness of the impressive Jeep Liberty". > > > >You may say that the back wheels just turn enough to not get dragged along, >but let me tell you, it is more than that, I have not had the front wheels >spin (on road) where you would expect them to. For example, there is a >intersection near me, and it's on hill, in the rain it becomes extremely >slippery, in my previous car (Falcon with LSD) with only light acceleration, >it used to fish tail out, a 1200cc Corolla could do it. This intersection is >notorious for this, so I tested it out one day, and I tried hard, but no >spin, so what I'm saying is, there is more drive from the back wheels than >you think. If the Aussie-spec Freelander gets the same Michelin XPC tires as in Europe, then a lot of that wet-road traction comes from the tires....neither Falcon nor Corolla would have come with those stock....:)) >Don't get it confused with "Real Time", (more like "unreal time") >now this is a system that is a case of shut the gate after the horse has >bolted. > You should do yourself a favour and drive a Freelander before you shoot >your mouth off and experience what sort of traction is achieved. >Scotty >P.S just to confuse things even more, I have noticed that Renault now has >"constant real time", there getting better and better at confusing ppl...LOL Only if you let them....:)) (you *really* don't want to hear the utter unbelievable nonsense I have witnessed multiple times, by multiple employees, at multiple Mercedes dealerships....bone-shivering utter nonsense....they are just lucky I am such a peacefull character, and managed to turn around, and walk away in severe depression, otherwise blood would have been shed....;)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 2002 17:34:22 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > Now please don't be mad at us....just buy a true fulltime with your next > vehicle....;)) I'm not mad at all, I'm very happy with the amount of traction I have, that works just as well as your Fulltime. BTW I have driven a Fulltime before, and can compare the two, more than you can say. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 02 21:10:43 GMT NEWSGROUPS: aus.cars.offroad In article <3cf1e03c@news.comindico.com.au>, "TD4GRUNT" wrote: > >> Now please don't be mad at us....just buy a true fulltime with your next >> vehicle....;)) >> >> >I'm not mad at all, I'm very happy with the amount of traction I have, that >works just as well as your Fulltime. BTW I have driven a Fulltime before, >and can compare the two, more than you can say. I know what dozens of expert testers have said before over the years, and I know what happens if you put those couplings under a constant strain.... I also know how many VW T2/T3 Vanagon Syncro owners faced a worn-out coupling, and converted to parttime.... While the Freelander might be the best of the reactive-pack, it's still reactive....and it's still a component to fail on you one day, overheated or worn out, unlike diff gears. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 2002 17:37:00 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > Read this to understand the difference: > > http://www.a1.nl/phomepag/markerink/quadrive.htm LOL why do I want to read this when you wrote it? FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 02 20:38:48 GMT NEWSGROUPS: aus.cars.offroad In article <3cf1e0da@news.comindico.com.au>, "TD4GRUNT" wrote: > >> Read this to understand the difference: >> >> http://www.a1.nl/phomepag/markerink/quadrive.htm >> >LOL why do I want to read this when you wrote it? That's the cute thing: I didn't write it, the largest German 4x4 mag did, with German gruendlichkeit....(and matching speeds). -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: "TD4GRUNT" SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 2002 20:28:17 +1000 ORGANIZATION: Comindico Australia Pty Ltd NEWSGROUPS: aus.cars.offroad > You can stand on your head if you want, but the only system capable of biasing > torque the very moment it slips is a torsen....anything else will have to detect > slip first in a rotational sense, and the only way to do that is by 'allowing' > slip in the first place; then engage, release after a while, see whether there > still is slip, and engage again if needed, ad infinitum. Your front tires *must* > spin before the system can react.... > (and the obvious designers preference for a very quick reaction (very little > rpm-differences needed) vs a delayed one is countered by the fact that a very > quick system will also bind in tight corners, which will *cause* slip on > ice....you can't have it both ways) ***Since you think you know so much about it, than please explain this! Giving it a lot of thought to what you were saying, I tried an experiment by which to prove the front and rear are locked together without relying on slip in the VC to lock the rear wheels. However I do agree there must be some slip to prevent axle wind up, so the VC must work like a LSD to a point. I jacked up one side of the rear so that the other wheel was on the ground (no LSD), and if your theory was right, I should be able to spin the wheel because of this slip in the VC before reaction, lazy axle theory, you reckon...Guess what!! Totally locked up, unable to spin the wheel because of the connection with the front axle. So if the VC works like a LSD, the rear wheels are driven always, constantly, fulltime, unless axle wind up happens. This also must happen with a Fulltime system, it has to have something to prevent axle wind up. How do you explain this!! > Your 90/10 system is no different than that of the Jeep Quadratrak-II (JGC, > 10/90), or the Subaru auto's of earlier models (90/10), and those are *not* as > stable in fast driven corners as their 50/50 counterparts.... > Read this to understand the difference: > > http://www.a1.nl/phomepag/markerink/quadrive.htm This system is basically what Real Time is, nothing like the system that is used on mine. I don't have to wait for hydraulic pressure to be created and lock a clutch pack in the diff, and in fact after the experiment I tried, I don't have to wait for anything, it's already driven. Scotty FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Locked centre diff v traction control DATE: Mon, 27 May 02 20:56:58 GMT NEWSGROUPS: aus.cars.offroad In article <3cf20917@news.comindico.com.au>, "TD4GRUNT" wrote: > >> You can stand on your head if you want, but the only system capable of biasing >> torque the very moment it slips is a torsen....anything else will have to detect >> slip first in a rotational sense, and the only way to do that is by 'allowing' >> slip in the first place; then engage, release after a while, see whether there >> still is slip, and engage again if needed, ad infinitum. Your front tires *must* >> spin before the system can react.... >> (and the obvious designers preference for a very quick reaction (very little >> rpm-differences needed) vs a delayed one is countered by the fact that a very >> quick system will also bind in tight corners, which will *cause* slip on >> ice....you can't have it both ways) > > >***Since you think you know so much about it, than please explain this! >Giving it a lot of thought to what you were saying, I tried an experiment by >which to prove the front and rear are locked together without relying on >slip in the VC to lock the rear wheels. However I do agree there must be >some slip to prevent axle wind up, so the VC must work like a LSD to a >point. >I jacked up one side of the rear so that the other wheel was on the ground >(no LSD), and if your theory was right, I should be able to spin the wheel >because of this slip in the VC before reaction, lazy axle theory, you >reckon...Guess what!! Totally locked up, unable to spin the wheel because of >the connection with the front axle. So if the VC works like a LSD, the rear >wheels are driven always, constantly, fulltime, unless axle wind up happens. >This also must happen with a Fulltime system, it has to have something to >prevent axle wind up. > How do you explain this!! I'll meet you at the local ice ring, and we'll do some pirouette's....;)) Or perhaps you were not strong enough to apply 10% of (maximum engine) torque?....;)) >> Your 90/10 system is no different than that of the Jeep Quadratrak-II (JGC, >> 10/90), or the Subaru auto's of earlier models (90/10), and those are *not* as >> stable in fast driven corners as their 50/50 counterparts.... >> Read this to understand the difference: >> >> http://www.a1.nl/phomepag/markerink/quadrive.htm >> > > >This system is basically what Real Time is, nothing like the system that is >used on mine. I don't have to wait for hydraulic pressure to be created and >lock a clutch pack in the diff, and in fact after the experiment I tried, I >don't have to wait for anything, it's already driven. There is a rather faul bottom line regarding the claimed 'perfection' of a center-coupling: *if* it were *that* good, why don't they use it between left and right tire(s) too?....;)) (even the JGC uses it only as an additional LSD in that application....but why not similarly in the center, as an LSD instead of a coupling too?....actually, that's the economic bottom line of center diff's vs couplings: they are cheaper, take less space, weigh less, cause less vibrations/noise, and in case of cross-placed engines, it's often the *only* way to design things anyway) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!]