RX-7 rearend in a miata
 

do any body use a RX-7 rearend in their car

I think we are all too cheap here.

lots of people but like braineack said it is expensive 1000-1200 dollars for the dif atleast. and will require a few mods. the 3.9 and 3.6 trosen swap is easier and cheaper. Plus it is about as strong. or so i have heard.

depends...
you can use a clutch pack LSD out of an FC.
You need the LSD pack from the FC, pop it in the 94+ miata open diff housing and use the 94+ halfshafts and driveshaft, it's nowhere NEAR 1000 bucks.

Now if you're talking about making an FD work, yes that's expensive.

Yeah i was just gonna say you can do the RX7 stuff on the cheap.

mine was less than $300 including having someone set the lash and load on the new rear end.
You guys are smoking crack.

I had to scroll my mouse wheel 4 times to ge tto the bottom of the Diff page....you know how much effort that must be.... j/k I never realized it could be done so cheap. I've heard of 1.8 swaps costing over $500 in parts.

I bought a nice LSD pack for 80 bucks at a u pull it yard, traded my viscous diff, 50 bucks, and misc parts for a 1.8 open diff, D/S and H/S, and paid a shop about 80 bucks to do the load/lash.

Not bad. I'm not thinking about mine untill it dies.

it was one of those things where I was walking through pull'n'save and saw a GTU RX7 and knew I could get the part cheap so I did it. The GTU is kind of uncommon.

Here's a helpful link with a parts list and how to:

http://members.aol.com/solomiata2/RX7LSD.pdf

I have a '00 open diff housing/gears, 89 RX-7 clutch type LSD, a new clutch pack with thick shims for more lock-up, '96 1 piece axles and a 1.8 driveshaft. All of this is sitting in my garage floor waiting to go in, but it appears that I may have to do this sooner than expected since my new found power from the 460cc injectors is too tempting to me. The total cost for mine is:

Differential housing/gears - $175
Rx-7 LSD - $100
Rebuild Kit - $225
Axles - $100
Driveshaft - $40

Total - $640

I lucked out and mine did not need a rebuild, it locked up just fine and appeared to have been done at some point.

heres mine

lsd and carrier $200
pumpkin $200
97 one piece axles $230 shipped
rebuild (didn't really need it but i got a deal) $160 for evrything

so thats $790ca for a brand new lsd, btw torsen sucks ;)

I rather liked mine too. Made a little noise IIRC though.

i wishh i could find someone who sets up gears in KY so far i have yet to find anyone who does any kind or rearend work anywhere. That is why i quoted 1 grand or more from buying complete rx7 unit and necessary parts.

then do it yourself, the RX7 FSM is available online and tells you how step by step, or mark everything and have someone press the old bearings on the new gears and put it all back together the same way.

:bowdown: I just might this winter if i get bored. it is very interesting beats waiting for my 1.6 rear to crap out. at 200 whp it doesn't have alot of time left unless i am nice to it:robert:

Yeah, just ask Miatanutca........:crx:
Mike:naughty:

hey guys thanks for the info I was wondering if it was worth fabricating some stuff for this rearend & if its even marketable.

thanks again tony

it probably would be if you could fab up a way to make the larger FD rear work.

There's nothing that needs to be fabricated to adapt the 7" RX-7 rear-end. It's the 8" from the FC Turbo II and FD that would require custom fabrication.

Just got word that the rebuild parts for my lsd are on back order til NOVEMBER!!!!! Good thing I have an insider working on parts from the states;)

I agree with bripad007,The only rearend worth fabbing up parts for is the FC turboII rearend.

If you ever decide to fab a kit for it,I will be the first one in line to buy one.

I didn't say the Turbo II or FD rear-ends were "worth" fabricating for, I said it would be necessary to fabricate some parts in order to use them. Personally, I don't think they are worth fabricating parts for; if you're in need of something stronger than the 7" rear-end, fabricate parts for using a 7.5" T-bird/Cougar rear-end or an 8-9" rear-end from a Ford or GM car.

would you rather have a solid rearend like a GM or Ford or independent rearend like a rx-7 TII & miata?

independent rearend like a rx-7 TII & miata.

I'm not talking about putting a solid rear-end in a Miata; that'd be useless.

I'm guessing you've never seen or read about the details of any of the 302/351, LS1/2/6 or 3.5L BOPR V8 conversions for the Miata, eh? :D

They use independent rears. Both 7.5" and 8.8", as I recall. Using those rather than the Mazda 8" rear has these benefits, in no particular order:

Cheaper.
Easier to find.
Easier to source parts for.
Many gearsets/ratios available.
Stronger (at least in the case of the 8.8").

If you're going to have to fabricate a custom mount, get a custom driveshaft and half-shafts built, you might as well go with the American rear-end(s).

Oh, and John Burch's "Cruise Missle" blown 347 c.i. Miata was running the 7.5" Thunderbird rear, so even the "measely" 7.5" is plenty strong for any of us.

What the miata community really needs is someone to build an adapter for the Turbo II transmission. With an upgraded 7" diff, it appears to me like the weak link becomes the transmission. I'd really like to see a bolt in upgrade with mounting points for the PPF.

dude people use the turbo 2 rears behind chevy V8 conversions, they hold up.

Turbo II's have viscous lsd's why would u want one???

The S4 Tubo II had a clutch-type diff., while the S5 has t he viscous.

As for the tranny, the 6-speed Miata/RX-8 tranny is stronger than the 5-speed, will retain the PPF and will bolt up to the engine without any extra work really.

The way I see it, if you want reliability, you follow these guidelines:

<250rwhp = 5-speed tranny w/ 7" rear
250-350rwhp = 6-speed tranny w/ 7" rear (the 7" rear has been used successfully with as much 470rwhp)
>350rwhp = T56 tranny with 7.5=8.8" rear

There's really no point in using the Turbo II tranny and rear unless you demand on keeping all the parts Mazda-sourced and you like notchy, difficult to shift trannies that're difficult to locate.

will if anyone needs an adapter plate for a 1.6 to TII tranny I have a template to cut one out.

Well, shit, that kind of changes things a bit.

Already having the tranny adapter plate in one's posession would definitely be a "pro" to going the TII route.

hey Brian can I get your e-mail address it seems your the man I need to talk to. I have some Ideas & pics to show you.

thanks tony

how sexy!