I am looking to install a torsen type two from a miata into my second gen race car, I am looking for sources for used units like this. Pick and pulls have shown me little luck so far and I dont want to buy it new. Also I have 4.33 gearing from the rx7, that would be fully compatable with the miata rear right? Is there any modification required to the rx7 in any way to fit the miata rear on, if so please describe or point me to a clear site describing it. Any any all info is greatle appreciated, thanks.

 

You would not be fitting the Miata rear on, you would be dis-assembling the Miata rear, removing the diff and replacing the FC diff with it.

The Miata rear case and assembly is different than the FC. You only want the diff. This part:


Not this part


Pictures are for reference only, they are not the actual parts you want, they just look like them.

 

But I could fit the diff into my current open rear casing without modification?

 

yes, the Miata Torsen diff fits into the FC case.

You would just swap your final gear onto the Miata diff before putting it in.

 

someone make a how-to!

 

I'll take pics and do a write up when I do mine next month.

 

Krane,

I had this same problem finding one for my 1st gen racer. The cheapest used one I could find was in the same $650 price range you can get a new one for from Mazda Competition. So, I just bought the new one. The first time you race the car in the rain, you'll think it was the best $650 you've ever spent.

 

Go here for some good info on swapping rear end pieces and the gear sets that are available.

http://mrmazda.members.atlantic.net/index.html

 

How hard is it to just install a 4.3 ring and pinion set into a 3.9 rear? Would it make more sense to just get the GTU rear and swap the whole thing? A new pinion set is like $500!!! I'm thinking I could find a GTU rear for about that same price.

 

http://mrmazda.members.atlantic.net/...l#DIFFERENTIAL


A few questions about that site. Mainly this section.

B-xx00 Pickup '87-8 4.444 4WD M/T

Does that mean I can switch out TII gears for the 4.444 out of the B series mazda pickups as a direct replacement or are there other things that I will need to change?

-Morbius

 

You could buy a whole new 4.1 NA type 1 or type 2 LSD rear end for $500+ shipping.

 

Where at? And what other parts need to be replaced during this conversion? I wouldn't mind upgrading all of the bushings in the area if they are going to be accessible. Do you need to remove the whole rear end to do this or can it be done on a rack with the rear still in the car? I thought about doing this before but nobody seemed to have any info on the swap.

 

Same as that rear assembly that I posted above,


mazdasurplus.com has them for $550 ($500+ $50 min order), or wait until they put it on ebay (they put it on ebay once a month) so you don't have to pay the $50 min order charge.

heres a series 5 type two one for the T2:


Thats only $375

 

why dont you get the 4.33 diff from the GTUs?
Justin

 

Can I get it for $500? Thanks for the info Icemark! Still wondering how hard the swap is, and if the whole rear needs dropped. Is it possible to just unbolt everything off of the differential and leave everything else still on the car? Will any axles work with those diff's?

 

Lots of good info on diffs and interchangeability at
solomiata.com
see also miata.net

Curtis

 

yeah I'm bringing up old post from the dead

but at least I'm searching


the miata diff can it be used with the TII rear end or only the N/A rear end?

the rear end for the n.a and turbo is different correct?

 

Miata Torsens only fit in a N/A rear end

But a FD torsen can be used in a T2 rear end.

 

how much does the FD torsen go for? would that be considered a wise swap for a s4 t2?

 

Seen used FD torsens go for around $200 on ebay. New ones are in the 4 digits.

And yes I think the Torsen is the way to go if your current LSD is worn out for the average driver or the driver racing on track or on or off road courses.

They however I hear are not great for drag cars.

 

my car has 132k on it safe to say my lsd clutch is gone

 

whats wrong with the torsen for drag?
understand that it won't distro power as wsell as a clutch type but anything else?


do you have a writeup on the lsd swap for the FD into the FC turbo rear?


and how many bolt and diam of the ring gear on the turbo rear end?

 

It is my understanding that the Torsens are not designed for drag applications, as the gears take more wear than normally expected when forced to start from a standstill with max power and high traction.

I don't have first hand info on this, its just what I have been told by racers in my area.

I imagine that the swap should be pretty straight forward, but like the Miata swap, the entire rear end would have to be disassembled and you would use your pinion and gear set bolted onto the FD diff guts.

 

That's a pretty sweet deal going here, but I have a question about those 4.44 gears. Do they work and if not how much would you have to go through to make it? Either way...the Miata Torsen sounds like a sweet piece to add.

 

Unfortunately not. The 4.44 truck gears are 7" ring ( NA-FC, 1.8 miata, first gen size) and also use a short pinion (like first gen rx-7 and 1.8 miata)

So even to put them in a NA-FC you'd either need the pinion extension (speedsource, etc) or to swap on a 1.8 miata or first gen rx-7 pinion housing.

I love the 8" TII rear because it's strong and LSD is plentiful/strong. But the lack of deeper gears is a bummer! (4.30 is about it!)