From what I've gathered from Miata people, the T1 has a little more bias to it, making it preferable on a race car. The Miata T2 is definetely not a T2R.

I found my T1 off the miata.net classifieds bare for under $400 (don't remember exactly). Most of the Torsens sold are a complete rear end meant to be swapped into another car without the hassle of swapping housings, so they'll be more expensive. There's not usually cause to take it out of the housing, unless maybe they're swapping to a clutch type or something. Keep an eye open, they do come up for sale at decent prices sometimes, but there's a real demand for them, so prices stay high. I beleive that an S2000 Torsen is the same as a Miata T2, so that's worth looking into as well.

 

Yes, some people also prefer clutch type differentials to torsens because they keep both wheels spinning, so in the event that one of your drive wheels has lifted off the ground (can be caused by sway bars, R comp tires, etc), the torsen will spin like an open diff while the clutch type will continue to deliver power.

 

Kool! Just the thread i was looking for. So the s4 (1986-1989) have LSD while the s5's do not? Please PM me or post answer plz?

I'm about to buy a 1987 Rx7 FC3S SE but don't know whether or not I'll have to buy an aftermarket LSD for it...

Oh and I didn't mean to jack your thread this is just a question that's been eating at me for a while LOL

 

The S5's got an (IMHO) inferior viscous LSD if they got one at all. So basically the only stock one that's worth anything only came on the S4.

As for the wheel lifting, on an FC, many racers run without a rear sway, and if they do the springs will be vastly more powerful than the sways, so if you're lifting it'll be because you ran out of droop travel on your shocks, or something else is causing it. More grip does lead to more roll, making it worse, but it's not the root cause. It is theoretically possible to have the sway cause tire lifting, but it's not going to be the case here, as you'd need very big bars with very soft springs.

You really should try to keep both back wheels on the ground anyway though, and most of the time that is the case, so this weakness of the Torsen isn't really a weakness 99% of the time.

 

Please direct your attention to the stickies in this section.....

 

rx7fan: yes but it's possibly worn out and no longer acting like an LSD, as clutch LSDs tend to do. A popular solution is the Miata torsen LSD. The internals swap right over, IIRC. FAQ and forum search will give you more info.

 

So will s4 rear ends fit in s5's? Are the halfshafts the same?

 

Yes and yes. The stub shafts aren't all the same though. The S5 viscous has different length shafts and will cause an S4 LSD or a Torsen to act as a locked diff. Not sure what they'll do to an open diff.

 

So if i got a s4 turbo 2 lsd and halfshafts i would be alright? thanks

 

No and no, did you not read the rest of the thread?

The TII diffs are 8" ring and pinion, the NA's are 7". Everything about the TII diffs is different. You'd need to swap the entire diff, get TII stubs (and half shafts?) and either change the transmission, clutch, flywheel, driveshaft and all that to TII stuff, or get a driveshaft (Mazdatrix has one) that goes from an NA transmission to a TII rear end.

There's two very different things going on here, there's the difference between the TYPE of LSD used in the S4's (clutch) and S5's (viscous), which is the same whether it's a TII or NA, and the SIZE of diff used in the TII's and NA's, which is independant of series. You can swap parts back and forth between the S4's and S5's as long as you use the same size, or do a whole or partial conversion. For racing, all the good, short ratios are available in the smaller 7" diff, which is plenty strong for NA engines, which is what gets raced 95+% of the time.

 

half-shafts = stubs

Our cars are not Hondas, Transmissions and Diffs are two different units.

 

Not exactly, the stubs are what go into the diff and terminate at the edge of the housing, the half shafts are what go between that and the hubs. Some would call that a 2 piece half shaft, but stubs != half shafts.

 

i think the guy is interested in drifting and as far as a torsen goes he prolly wouldnt be happy with it. they like to open up while doing banks and unfortunately alot of events are at oval tracks

 

aftermarket diffs for miatas fit na's.

ie, an ats or kaaz 2way.

 

Aren't the axles what go between that and the hubs?

 

I got a S5 with a welded NA diff.. id like to swap to a lsd, im thinking maybe an S4 gxl clutch lsd and pack it with new disc from mazdatrix, or maybe a early miata torsen. Do they sell parts for the miata diff to give it more lock?

I believe ive seen both at a junk yard before.. would both be likely canidates for what i want? daily driving, yet aggressive for track and drift? The welded doesnt bother me on daily but i just know if i do autocross im gonna be sliding all over the place which id probably get in trouble for lol. I would not mind if i could pick one up from my local junk yard, and maybe on a spare weekend or something just take it apart and pack it with more discs.

 

Well half shaft are the axle shafts (half an axle, hence half shft).

The Miata diff is not rebuildable for more bias. It's a completely different concept than a clutch type like in the S4's. If drifting is in the equation then get a clutch type. Don't go and order all the parts to rebuild before taking it apart and checking the tolerances. Chances are that you can just replace the springs and washers to give it more lock, or maybe replace only some of the plates with the thicker Mazdaspeed ones to get it back to working order. If you replace everything you're into the sort of price range for a KAAZ or other aftermarket diff.

 

just the thread interesting reading, i have a GSl-SE S3 with the larger axle, im in the UK and we didn't get the LSD's on the S4 so i'm looking at the Miata swap as we have plenty of them, has anyone do this swap? will i just need the lsd unit? surley life isnt that easy!
Mark