Miata Rear-End
 

There has been a lot written about rear-end swaps for the first gen RX7, both here and on the net. But I am still unsure how to get an aluminum rear-end assembly into my 1980 RX7 SA. Can I swap a Miata rear-end into my car with just some grinding and brake line adapters? If so what years? If not is there a RX7 swap that is aluminum and that will fit my car? Thanks.

If this is true... plz let me us know... i would also like to know if i can put hubs on it to get matching bolt patterns. I'm trying to build a list of things that i can do and start saving the cash up. after jan of 06 will be able to start putting money toward the car to get it fixed up. would be nice to go all wheel disc.

Are you talking about just the pumpkin or the entire independent rear setup? There's a guy here that had some good pictures of his install on his V8 FB.

Check it out...
https://www.rx7club.com/showthread.php?t=457637

Thanks for the link!
 

I just email Rob about that rear-end to see if it will fit.
Thanks

The whole Thing
 

I would like to swap the assembly so that I can get disks in the back and a better bolt pattern.
Thanks!

Not having done the swap but being very familiar with each, I would put it somewhere above installing a 3-link/panhard setup and just below building your own tube frame car from scratch.

You'll have to cut the frame and adapt it (frame rails are different for live axle and independant rear cars). You'll need to fabricate a way to keep the rearend in line with the transmission. The Miata's have this aluminum brace everybody calls a PPF: it bolts onto the diff and the tranny. It would probably be easier to just adapt a Miata tranny to the rotary (same bolt pattern as far as I can tell, different slave cylinder location [bottom passenger site, FWIW]). Brake lines are probably the least of your worries; just get some stainless lines. I think the driveshaft splines are the same on the two cars, but I don't know if the length is. It seems like the Miata is shorter, but I've never compared the two side-by-side.

So, in short, probably a worthwhile swap but a fairly tall order in the fabrication skills department.

Sorry,but if you dont realize the IMMENSE differences between the Miata IRS and the FB solid axle,then this isnt a project to be attempting.
Its not in the least bit a "grind and prod" type install.It requires you to essencially redesign the entire back half of the car's structure,to accomidate the different pickup points for the IRS sub assembely.
If you want discs and a better bolt pattern,get an SE rearend.Its basically a drop in,the SE discs are way bigger than the Miata's and the 114.3MM SE pattern is very common.

Didn't know
 

I had no idea that the Miata was independent rear!
All the talk about swapping parts made me think it was solid.
Any aluminum rear-ends bolt into my SA?
Thanks

Get you a gsl complete rear end. You will have limited slip and disk brakes.
If you want to change the pattern well get you a complete GSL-SE suspension.

I have a gsl rear and a complete gsl-se suspension. One of them will be going on my 1980 once I figure out what wheels I want to run. It is am easy swap.

Well, in SCCA E Production the 1st gen Live Axel rear car is still very competetive and a front runner against.......... Miata, Prelude, 2nd Gen Rx7, and the light nimble Caterham 7. I'd spend my time and $$ elsewhere. Not to say it's a bad idea, just that the cost - time / benefit ratio is not very good.

I'd put the time and $$ into motor / suspension / tires / and *track time*.

Thanks
 

Sounds good, I'll be looking for a GSL-SE rear-end.

I'm focusing on the rear-end because I'm sure which way I want to go with the rest of the car.

Is the GSL-SE aluminum?

Thanks,
Vin

You can do that by getting a GSL-SE rear end. Why go overboard?

What's with your hard on for aluminum?

Aluminum
 

Just for weight.

The Miata rear assembly is at least 50, possibly 100 pounds heavier than a GSL/GSLSE rear. :crazy:

Bought GSL SE Rear End
 

Just got my new(used) rear-end home... GSL SE with clutch LSD.
I have a new(new) torsen laying around. Maybe it'll fit.
Thanks for all the help,
Vin