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Location:
Auckland, New Zealand
Registered:
October 2002
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4wd and LSD's - advice needed
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Wed, 14 January 2004 20:25
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OK - heres the scenario. My ST215 caldina GT-T is 4wd with a front / rear split of 40/60 so im told which is supposed to give the car a rear wheel bias and feel when driving.
Now I have issues going up ramps (such as the one in my carpark building) as i have to go up on an angle due to the low front. When im part way up the ramp I usually always get 1 rear wheel breaking traction. The car just then sits stationarry and that 1 rear wheel spins. It infuriates me no end that the front wheels dont come to the party and pull the car up the ramp - but no - they dont.
So if i were going to install an LSD, which diff do i want to replace? The rear one? Would this alleviate my current issues with complete loss of traction when 1 rear wheel spins freely? Or would i be better off looking at the center diff (which i assume is what allows the 40/60 torque split front to rear)? And finally how would replacing either of these affect the driving of the car either round town or at speed? I would not replace a diff just to resolve my car park building issues, but if it will improve the handling of the car overall i will consider it.
thanx.
AL
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Location:
c'town, NSW
Registered:
May 2002
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Re: 4wd and LSD's - advice needed
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Wed, 14 January 2004 21:17
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check to see if u dont already have a torsen LSD in it.
a torsen LSD is a torque multiplying LSD, so 0 torque on your spinning wheel will mean 0xN torque being sent to the other wheel, and of course 0 times anything equals 0 and no getting up the ramp.
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Location:
Auckland, New Zealand
Registered:
October 2002
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Re: 4wd and LSD's - advice needed
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Wed, 14 January 2004 22:41
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This is the rear diff you are talking about right?
I dont think it does have a LSD as TRD offer a rear LSD for my vehicle...
How would i tell if it has a torsen LSD in it?
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Registered:
June 2002
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Re: 4wd and LSD's - advice needed
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Wed, 14 January 2004 23:51
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The only way (other than pulling it apart) it to check the diff codes at toyota.
Sounds like it needs a LSD centre, my 323 gtx use to do the same during hard cornering (lift the rear wheel, then no traction), So I installed a LSD in the rear which solved that problem but then the inside front started spinning.
So just changed the problem really.
My Evo 1 has LS rear and centre diffs so it does not have these problems, I think your old GSR would have had only a LSD centre.
Or viscous coupling bullshit thing (LSD anyway). So it wouldn't suffer from your current problem.
My useless 2c.
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Location:
Brisbane
Registered:
May 2002
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Re: 4wd and LSD's - advice needed
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Thu, 15 January 2004 00:08
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Next time you have this problem, try lightly applying the brakes while accelerating up the ramp. If you have a torsen LSD, this will load it up and allow the torque multiplication to come into effect. It's a well-known trick with torsens.
Of course if you have an open diff this won't help you at all. Try checking the axle codes on your build plate, that should tell you what diff(s) you have.
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Toymods Club Treasurer
Location:
Sydney
Registered:
May 2002
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Re: 4wd and LSD's - advice needed
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Thu, 15 January 2004 00:15
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No GT4 was available form the factory with a rear LSD, so I severely doubt the Caldina has one either.
Cheapskate Toyota, all the Subaru turbos since they started the Liberty/Legacy have had a rear LSD.
I'm not sure what centre diff are in Toyotas, as it should still be supplying some power to the front wheels which should then pull slightly.
Are you sure that the torque split is 40/60 front/rear? All the GT4's until the ST205 had it the other way round, altough Toyota may have just put the ST205 gearbox in the ST215 Caldinas.
If you are going to replace a diff, I'd definitely recommend a rear LSD for the 4wd, you can actually get a rear drift going if you get the technique right (and only on slippery surfaces). I could do this regularly in my Legacy GT.
Before this maybe get the centre diff checked out, unless someone else can shed light on the centre diff arrangement.
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Location:
Auckland, New Zealand
Registered:
October 2002
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Re: 4wd and LSD's - advice needed
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Thu, 15 January 2004 00:32
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Since most of my car is based on the ST205 i would assume the drivetrain is too including the diffs. And no im n ot sure of the 40/60 f/r split - i was just told that by someone... cant even recall when or where... Ill check the trans codes tonight n post em here 2morrow...
Ill try that trick w the brakes - cheers, but i suspect open diffs all round.
Cheers, AL
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Location:
Auckland, New Zealand
Registered:
October 2002
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Re: 4wd and LSD's - advice needed
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Thu, 15 January 2004 23:02
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Ok heres the trans info of the plate:
Tans/axle E150F -08B
Anyone shed any more light on this?
Thanks
AL
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Location:
Adelaide
Registered:
October 2003
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Re: 4wd and LSD's - advice needed
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Thu, 15 January 2004 23:54
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If I may clarify, a Torsen LSD is Torque Sensing (hence the name torsen) and will send torque to a wheel that has grip, and away from one that does not. They aren't particularly common in japanese production cars until recently. I don't know much about GT4's and Caldinas, but I'd be surprised if you've got one. It sounds very much like open diff behaviour to me. You'd probably find you've got a Viscous centre diff that provides the split, and open front and rear. Torsens are a good choice for a daily driven car, they are very predictable to drive. Other choices are clutch or viscous. Viscous will behave like a normal diff for a little until it 'warms up' and then will lock. Good fun in a RWD car because you get that moment of sideways before the launch. Clutch LSD's are much the same, but depend on the power being put into the diff.
Cheers
Mike
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: 4wd and LSD's - advice needed
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Thu, 15 January 2004 23:57
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Most of the later model Toyota's (that have LSD's) use a Torsen, including the 93+ Mk4 Supra. Even the JZA70 Mk3 Supra used it before then. Mazda used it in their S6+ RX7 too. Although Nissan didn't tend to use them until recently, I wouldn't say they were a recent introduction.
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Location:
Colac, Victoria
Registered:
May 2002
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Toymods Club Treasurer
Location:
Sydney
Registered:
May 2002
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Re: 4wd and LSD's - advice needed
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Sat, 17 January 2004 05:21
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Only going on what others have told me, if I'm wrong feel free to correct me.
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Location:
Colac, Victoria
Registered:
May 2002
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Re: 4wd and LSD's - advice needed
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Sat, 17 January 2004 11:31
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im 99.95% and have confirmed with 2 sources so far that they are torsen at least for the rear end of the three mentioned above ..
Neal bates motorsport + canberra toyota - i think its mal there -seems very cluey on Gt4's both back this up.
So i guess - going by the caldina using gt4 running gear - you shuld have the goodies there - but its a wierd situation thats being described.
though as far as i know the Gt4's were also a 50/50 split .. they may have changed this in the caldina
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