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99 Aspen White Coupe
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Discussion Starter · #1 ·
Yes, I know there is already a ton of info out there, but I haven't seen anyone address this. Mechanical LSDs essentially act like open diffs if you lift a wheel, but what about if you're on ice or something with essentially zero traction? I'm getting tired of my open diff, not only for handlings sake, but also because I drive through a very large amount of snow and need all the traction I can get. So will a Mech LSD do this, or am I going to need to fork out the dough for a clutch type (or settle for a VLSD)?
 

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overdeveloped beater
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You have your info mixed up. Mechanical is not the same thing as a TorSen (helical). It is the helical diff that acts as an open when no torque is available at the slipping wheel.

A mechanical LSD will pull you through the snow and get you off the ice.
 

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Discussion Starter · #3 ·
OK, no I'm confused. I thought that a mechanical one used the Torsen design. So what's the difference exactly (on a mechanical level)? How does each work? Somone should just lend me one to play with and take apart, it would keep me entertained for a while.
 

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Discussion Starter · #5 ·
Some good info there, especially on open diffs (knew it already, though ;) ). However, it only talks about Torsen and Quafie, both of which require a level of torque on both sides, meaning both tires need traction. So I'm a little confused about what storm said still.
 

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Discussion Starter · #7 ·
Is that what the JDM mechs are though? I'm familiar with those (I was into offroading for a while), but didn't think a street car would ever come with something like that.
 

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overdeveloped beater
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Terms get tossed around on the net that makes things confusing. For example, the link discussing TorSen and Quaife? I didn't go to the link, but I know that the Quaife is a TorSen design, using helical gears to transfer torque.

Mechanical, as I know it, would be a locking type with serrated plates that transfer torque equally when closed.

A clutch type would include simple springs pushing plates against the outer bevel gears, as well as multiplate clutches providing resistance when axle speeds are different.

One can't label an LSD simply as "JDM" because they had different types too. In short, you gotta do your homework looking at pictures with descriptions or the actual different types in your hand to see how each type works and what the pros and cons would be for them.

This is my clutch type rear diff. Others have called it a JDM LSD, but it came off a 1989 USDM XT turbo.....so go figure. It works great, btw.... :)
 

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Discussion Starter · #9 ·
Sorry, when I said JDM, I just mean the mechanical R160, since it seems to be very popular. I know just being JDM means nothing.

I'm still a little skeptical about a locking mechanical on a street car, I'd think it would be a bit clunky and a handful, but I'm going to take your word for it, since I don't have one to look at in person (I'm that guy that needs to hold it and move it around to get a good understanding).

I'd forgotten that Subaru used to use clutch type LSDs, I'm guessing that's a hell of a lot cheaper than a Cusco or something else along those lines. I might start looking for one of those, as I know it would do everything I want it to. Where did you find one and how much do they usually run? And which axles does it need? And we're they ever 4.11, or am I going to be swapping the ring and pinion? I've never set backlash before, so I'm a little nervous about that, but I'm sure I could do it.
 

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MY99 GF4 EJ227 JDM 6spd
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When getting clutch LSDs, it is definently worth the $$$ to buy the good stuff. I don't quite like my R180 2way LSD, but I'd take it over an open anyday. I wished it was stronger.

KAAZ is the way to go! Let me get mine next spring and I'll show you wassup.
 

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I'd forgotten that Subaru used to use clutch type LSDs, I'm guessing that's a hell of a lot cheaper than a Cusco or something else along those lines. I might start looking for one of those, as I know it would do everything I want it to. Where did you find one and how much do they usually run? And which axles does it need? And we're they ever 4.11, or am I going to be swapping the ring and pinion? I've never set backlash before, so I'm a little nervous about that, but I'm sure I could do it.
The early JDM WRX used 4.111 mechanical LSDs that would bolt right into your car. When you buy one, be sure you get the axles that go with it as they can not be found easily in the US. There are a couple of vendors on here that normally sell them for ~$400.
 
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