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  #11  
Old 12th February 2014, 01:29 AM
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Quote:
Originally Posted by Ratbag View Post

Just checked in the OM for our MY06. Mine does not have VDC. It states "If Equipped", so was an option somewhere in the world ... .
Don't quote me but no SG Foresters (in Australia anyway) have VDC apart from I think in the SG2 era when there were some XTs available with a special option pack that included VDC and a navigation unit that replaced the lift-up compartment on the dashboard. Might have only been available in auto too but my memory is hazy on the whole thing and I suspect they are quite rare. "If equipped" indeed!
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  #12  
Old 12th February 2014, 01:34 AM
MiddleAgeSubie MiddleAgeSubie is offline
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Well, 2015- US OBs will have neither VTD, nor MT so....

(it seems that VTD will be replaced by another, simpler yet faster system; I do not know how well it will work off-road).
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  #13  
Old 12th February 2014, 01:40 AM
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Quote:
Originally Posted by BeeJ View Post
a great illustration of diagonal situation and the centre manual diff, vs auto MPT vs VTD
VTD in itself is of no help in a 'diagonal spin' situation as it only controls the front-rear disribution. It is the VDC that overcomes cross-axle wheelspin and helps with 'diagonal spin' by braking the spinning wheels.

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Originally Posted by BeeJ View Post
vLSD is *****house! almost everyone agrees its almost a ***** as a open diff!
Certainly my rear VLSD may as well be open. It provides no resistance to cross-axle wheelspin at all. The centre one is a bit better however.
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Old 12th February 2014, 01:44 AM
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Quote:
Originally Posted by MiddleAgeSubie View Post
it seems that VTD will be replaced by another, simpler yet faster system; I do not know how well it will work off-road.
That is interesting. Any links to this info?
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Old 13th February 2014, 12:51 AM
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No, it was discussed briefly over at subaruoutback.org. The VTD is a feature of 5 EAT Subarus. The last of those are going off the lots now....

I guess we will know more in April. But initial reactions have ranged from "yes, what we will have is even better" to "no, it is just cheaper to make, not as good."
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Old 13th February 2014, 12:52 AM
MiddleAgeSubie MiddleAgeSubie is offline
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No, it was discussed briefly over at subaruoutback.org. The VTD is a feature of 5 EAT Subarus. The last of those are going off the lots now....

I guess we will know more in April. But initial reactions have ranged from "yes, what we will have is even better" to "no, it is just cheaper to make, not as good."

We do not really know, but the Legacy press release says nothing exciting.
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Old 16th March 2014, 10:00 PM
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Quote:
Originally Posted by simxs View Post
VTD in itself is of no help in a 'diagonal spin' situation as it only controls the front-rear disribution. It is the VDC that overcomes cross-axle wheelspin and helps with 'diagonal spin' by braking the spinning wheels.
Spot on.

Quote:
Certainly my rear VLSD may as well be open. It provides no resistance to cross-axle wheelspin at all. The centre one is a bit better however.
I drove a modified 4.44 VTD auto with an early VLSD rear offroad for about 7 years. I don't necessarily agree here. A VLSD works by getting hot. If you keep the boot into it you will feel the rear lock up and propel you forward. obviously not something you want to do all the time but it got me out of trouble plenty of times.
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Old 16th March 2014, 10:03 PM
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by the way VTD has been around since the early 90's. its not a new thing

I have 2 VTD rear ends I need to get rid of if anyone wants to modify their auto...
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  #19  
Old 17th March 2014, 06:46 AM
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Quote:
Originally Posted by simxs View Post
Don't quote me but no SG Foresters (in Australia anyway) have VDC apart from I think in the SG2 era when there were some XTs available with a special option pack that included VDC and a navigation unit that replaced the lift-up compartment on the dashboard. Might have only been available in auto too but my memory is hazy on the whole thing and I suspect they are quite rare. "If equipped" indeed!
Hi simxs,

Yes, you are correct! The only XTs that had VDC available as an option were the top of the range XT Luxury with the 4EAT transmission. Still, it was only fitted as a package with the OEM navigation unit. The VDC is an add-on feature of the VTD centre differential.

My car is a 2007 SG2 XT Auto (4EAT) with the OEM navigation. But mine's not a LUXURY, so I don't get the VDC, only the VTD centre diff as opposed to the MPT standard on other 4EATs. This was the case with all 2007 XT autos.

From the video on the first post, what really makes the difference is the VDC, in other words, the traction control monitoring of wheel-spin and individual brake application where required.

You can see on the first ice section how much the vehicle looses control when VDC is off. Straight after, with VDC turned on, it goes through in total control.

Now, my personal experience with VTD alone is also quite positive when compared to other 4EAT autos I've driven with the standard MPT, so I tend to agree with the results shown on the video:

1) VTD + VDC - best control
2) VTD only - good control
3) Auto MPT - ok control

I haven't spent enough time behind a Subaru manual to comment.

BeeJ, I thought your video find was a very nice one and certainly aligns with my view/experience.

Pedro.
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  #20  
Old 17th March 2014, 07:00 AM
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Out of interest, I will quote my sources:

The MY07 brochure and specifications can be found here.

And the explanation of the MPT vs VTD centre differentials, as well as VDC is here.

Both documents are interesting reads on a range of topics. They are not my finds, I collected them from other posts on the forum.

Pedro.
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