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Are you sure this will fit the XT's? Would our 4.44 gearing be retained? Do you think the trans would have to be pulled and taken apart to install this? This is looking like a $2,000 mod after labor.

i'll let you be the guinea pig! :biggrin:
 

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2005 Forester XT 4EAT
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2,160 Posts
Discussion Starter #3
Are you sure this will fit the XT's? Would our 4.44 gearing be retained? Do you think the trans would have to be pulled and taken apart to install this? This is looking like a $2,000 mod after labor.

i'll let you be the guinea pig! :biggrin:
Well the ring gear that would be bolted to the diff would determine the ratio, and yes the trans has to be pulled and it's gonna be pricey, but my trans almost has to be pulled out to do the motor swap anyway, so it's gonna get done with the motor.
 

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2009 Forester XT Limited
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376 Posts
Beware of mismatching gears, I have heard that it can cause problems to just swap one gear and leave the other however I don't know as that's true personally, good luck with it.
 

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Beware of mismatching gears, I have heard that it can cause problems to just swap one gear and leave the other however I don't know as that's true personally, good luck with it.
This doesn't replace any gears. You keep your pinion and bolt the ring gear to the LSD. The LSD replaces the spider gears in an open diff.

I might be in for one as well, the open front is one of the MAJOR downfalls of the 4eat (especially with the MPT).

*subscribed*

The torsen style is exactly what I had hoped for in the front end, should have come with one from the factory!
 

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2005 Forester XT 4EAT
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2,160 Posts
Discussion Starter #7 (Edited)
Beware of mismatching gears, I have heard that it can cause problems to just swap one gear and leave the other however I don't know as that's true personally, good luck with it.
I called the company and spoke to them about the diff, apparently a lot of 15 were shipped to the states. 1 guy bought a diff, the rest have been sitting collecting dust for the past 5 to 6 years. I don't know who realised they would work in a subaru, but the guy said the ratio will be whatever ring gear is bolted to it, so of course my ring gear is 4.44 so there shouldn't be any problems.
 

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If they have been collecting dust for 5-6 years, they should cut the $1100 price tag and have a group buy...

Somebody buy me one!! I'm tired of crappy launches!:icon_razz:
 

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2007 FSTI and X 6 MT
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If they have been collecting dust for 5-6 years, they should cut the $1100 price tag and have a group buy...

Somebody buy me one!! I'm tired of crappy launches!:icon_razz:
Exactly, like the same ratio that the ravspec lips were. Retail was 400. Closeout was 150!

Make a gb happen, for like 500 bucks each!
 

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2009 cts-v 6 speed smg
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764 Posts
just buy the obx one if you get a wheel off the ground it will send all the power to the wheel in the air wheeeeeeeeeeeeee
 

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2009 Forester XT Limited
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376 Posts
This doesn't replace any gears. You keep your pinion and bolt the ring gear to the LSD. The LSD replaces the spider gears in an open diff.

I might be in for one as well, the open front is one of the MAJOR downfalls of the 4eat (especially with the MPT).

*subscribed*

The torsen style is exactly what I had hoped for in the front end, should have come with one from the factory!
Sorry about that, I misunderstood and thought there was gear swapping involved.
 

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Smooshed FOTY 2011
2005 Lifted 2.5 XT 5-Speed MT Dual-Range
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5,734 Posts
My question is would this behave any differently than my worthless rear LSD when off road (when one tire is off the ground, and the other isn't)???
 

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2003 WRX
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g00fy and I have been talking over on NASIOC and he directed me over here. So I thought I would just answer a couple of questions.

First, this diff was designed for the automatic Subaru 4AT transmission, not a Porsche. The initial run of 15 was sent over here to the US distributor for Modena, and they specialized in Porsche's, so they have been sitting around for quite some time. But in Australia, Modena does make a lot of Competition Rally gears and differentials for Subaru's.

For instance, the Subaru US Rally Team is using Modena's sequential 6MT gear box in both of their cars.

As far as using this differential for off-roading, you would be better off with a clutch type LSD, rather than this Torsen Torque Biasing Differential.

Because this is a Torsen differential, what it does is make sure that 100% of the torque that is sent to the differential is distributed to both front wheels, where as the stock open differential will only drive one wheel.

However, in a situation described above where one wheel is up in the air, that one wheel can accept 100% of the torque, so the other wheel will not be driven.

With a clutch type LSD, this will actually lock the two front (for this discussion) wheels together, so even if you have one wheel that is up in the air, the other side will still be driven.

However, keep in mind that though an LSD is better for driving in slick/off-road conditions, there are some draw-backs to this set-up when driving on the street/tarmac. The main one is that this type of LSD will cause understeer because it does lock the front wheels together which forces them to turn at the same speed, which basically over-drives the inside wheel.

FWIW, our Rally Car has a Cusco Clutch-Type LSD in the front (and the rear for that matter) and it is a handfull to drive on the street. Not to mention that the diff's make a lot of racket. However, at speed on dirt, they make all the difference.

Thanks guys, and I hope that this diff helps to solve some of the problems that you are having.
 

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2006 Forester XT Limited 4EAT
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Group buy @ >discount to clear inventory!
 

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My question is would this behave any differently than my worthless rear LSD when off road (when one tire is off the ground, and the other isn't)???
As flatiron said, with a wheel off the ground a torsen style is basically useless. However in low traction situations it would help. A clutch type LSD would be better, but a phantomgrip style autolocker would be the best of the available options for offroading since there are no air or e lockers for the subaru diffs.

IMO a torsen front with a 1.5way clutch rear would be the best setup for a subaru, and now we can finally do it with the 4eat.

If there was a group buy for these I'd be interested (if I could come up with the cash).
 

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99 UK S-turbo
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As flatiron said, with a wheel off the ground a torsen style is basically useless.
Actually, like a plate type it depends on the preload, a low preload clutch type is useless with one wheel in the air as well, however where the preload on a clutch can be set at sily levels if you want, the ATB cannot be proloaded by much, typical max torque transfer unloaded is around 60Nm, or around 1/8th of the wheels 25% share of torque coming out the trans in first gear.

Simon
 
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