Whizbang

reading somewhere, in somearticle i found out you can use the torsen LSD from a 94+ 1.8L miata by combining a few parts. now it said something about using a S5 housing with the S4 axles. now, why cant i use an s4 housing and s4 axles? do i really need a s5 housing for this?

jreynish

iTrader: (2)

why not just go to a wrecker and get a LSD for you car?

Whizbang

this is for a ITS project and the torsen (which doesnt rely on clutch plates and fluid to determine the delta bewteen the wheels) is superior. Plus, any LSD from a 80's vechile is going to be well used and in need of a rebuild or will not be "up to par"

Whizbang

that and you need a differential that already had a LSD in it (the vicious FC style) in order to preform the swap correctly. or a least that is what the article is suggesting.

TitosToy

here's the thread on the write-up:
http://64.9.213.132/rx7club.com/foru...ight=miata+lsd

enjoy

Kenteth

in the archive

Rxmfn7

iTrader: (4)

It was me that wrote the thread in the archives about swapping the miata LSD> It doesnt matter if you use S4 or S5 housing, and it doesnt matter if the rear end had a LSD or not originally. The only thing that matters is that you use equal-lenth axle stubs, like the ones on the S4 N/A cars.

mycarisolderthanme

so, rxmfn7, after all this time, are you satisfied with your rear end?

Rxmfn7

iTrader: (4)

Haha. I dunno, I sold it shortly after it was assembled. I believe "crispyrx7" has it now.

Steel

so rxmfn7... you do rear end and transmission work... interested in rebuilding mine?

C. Ludwig

iTrader: (27)

Keep in mind while the Torsen gives good service as a race diff they are fragile and they will break. ISC talked me out of using one when I called to have a new diff built for my car. The clutch types do wear over time but according to Mike the wear rate is not that great and the life to rebuild of a clutch type is about 4 times that of a Torsen. The Torsen breaks and parts are not available to rebuild them. According to Mike a Torsen should last about 20 weekends of racing if you have a lubrication modification done to them. They won't last as long if you don't. Have also talked to a few endurance racers who learned about the service life of a Torsen the hard way. Something else to consider is that a Torsen goes open when one wheel is in the air. Something to keep in mind when hopping curbs.

In the end I've been completely satisfied with a properly built clutch type.

Whizbang

i wonder if anyone makes a rebuilt kit for the good ole cltuch type LSD's off a 7....

Rxmfn7

iTrader: (4)

Yes, you can order the parts off Mazdatrix. Also, read over the post made above by C. Ludwig, everything he said is very viable. ALthough , on a street car, weekend racer, I do not think the Torsen breaking is much of an issue. I personally would rather have a clutch type LSD over a torsen. The only reason I swapped the torsen into the rear end I had in my write-up, was it was a GTUs 4.3 rear end, which had the viscous LSD, and I got a hell of a deal on a miata tosen from my locak junkyard. Keep in mind, Miata people swap in FC clutch type LSDs, and FD guys swap in S4 Turbo2 LSDs. In my Turbo FC, I have an aftermarket KAAZ clutch type LSD.. clutch is the way to go

Whizbang

kinda looks like i am going to just stick with the clutch type. its an n/a so i doubt it could have destroyed the torsen but still. that and i am trying to convince the mazda dealership here (which is a section of the huge *** Classic dealership) to give me a quasi-spondership for stock parts. at discount for free or whatever. i am hoping the dealer can get just the ring gear from a GTUs. would be a nice gift from them to me.

RETed

This one caught my eye...

So what does a clutch-type LSD do when one side totally loses traction?
I was TOLD that a clutch-type does not lock up when one side is totally up in the air.
I had my car three-wheel in a banked driveway and my stock Turbo II LSD did NOT engage at all - I assumed it was worn.
This was TOLD to me by maxthe7man, and I thought it was full of ****, but he claims the clutch-type LSD will not engage when one side has zero traction.


-Ted

Icemark

Hmmm, Intresting Ted.

I thought that if one wheel is in the air, only a Torsen will lock... all others free spin because they need to the speed differential between the wheel to lock.

FarNorthMotoring

iTrader: (2)

I can't speak for the other types, but I do know for a fact that a Miata torsen requires both wheels. If you apply a little ebrake for friction, it will work though.

sbd

It is exactly the opposite. Torsen needs some traction to lock. Having one wheel in the air makes it an open diff.
The clutch and visko types a speed difference sensitive, so if one wheel turns faster than the other no matter if in the air or not, the diff locks (assuming the diff is not worn).
e

Icemark

No I think you arwe wrong.

If one wheel is in the air (from say a too sharp turn) the wheel in the air is moving as fast as the other wheel. Friction losses for the few miliseconds that the wheel is in the air is not sufficent to slow that wheel down enough to lock up either a clutch plate or viscous LSD.

Heck most viscous LSDs need about 1.7 turns of the opposite wheel just to start locking.

And Torsen units lock by gear plane, so they actually transfer traction to the wheel with the most traction, rather than truly locking. So your wheel on the ground will have most of the output, not the wheel in the air.

sbd

This may be valid only in case a wheel loses truction for FEW milisecond. In the case Ted was talking about, one wheel permanently(more than few miliseconds) in the air, it works as said in my previous post.
The message of any LSD is to transfer TORQUE to the wheel with most traction and neither truely locks up.
A torsen to work NEEDS some traction for the loosed wheel.
May I recomend you this article http://www.torsen.com/files/Traction...ol_Article.pdf