is a miata trans close enough to put in a n/a rx7?
and what would i need to do it if it is possable
any ideas would be a great help thanks!

 

As far as i know you'll need a 94+ miata diff (torsen diff)
They fit in NA diff housing

 

i have a lsd and 4:3 gtu gears i am wanting closer gear ratios
(i.e. 95 miata 5 speed)

 

The internals of the miata transmission swap right into the FC case. Atleast one member has done the swap, hopefully she will chime in.

 

ohhhh, the wonderful wonderful claire............................................ .

 

wow...does it make you squirm that I saw her in the shop last week :P ? I forget what I was buying, I go there too much.


As for the Miata gearbox swap, check out a thread by RXgirl7, on the last page there are links to good info.
I just picked up a 94-98 Miata transmission yesterday and will be doing the swap for my 86 S4. You can use a <94 transmission, same gear ratios and all, but with all the +94 transmissions available, start it with something newer.
Initial inspection/comparing the miata and a s5 trans, the input shaft is different on the miata box. I will be using the s5 transmission as the donor case and taking the .697 fifth gear out of it also... still need cruising for my road trips.

 

the link:

https://www.rx7club.com/showthread.p...ht=miata+trans

 

Hey, looks like I'm late to the party! Yes, the miata trans will work in an FC. You will need to swap the gears into the FC case, and have the imput shaft re-splined at a good machine shop. Check out the thread for more details, or pm me with questions. I would do this swap again in a heartbeat.

 

Lol, when did this happen, and why did you not say hi?

 

hah was on my lunch break, i have no doubt ill be there again soon for this project

the input shaft needs to be resplined? It was pretty late when I started taking them apart but I am pretty sure i counted the same amount of splins

 

It's not the number of splines, its the length of the splines. It needs to be shortened. The easiest way to do it is take the miata shaft and the FC shaft to the machinist and have them "make this one look like that one".
Now would be a good time to slap on a nice aluminium flywheel

 

Enough with the leghumping. If you want to do that stuff, do it in the Lounge. It ads nothing to the thread...

As for the original poster, RXgirl7 has a topic in the Archives that thoroughly covers her installation of a Miata transmission.

 

angel grinder and sand paper shoudl do it!

 

leghumping? seems pretty calm to me, not even one mention of PIIDB


I was thinking about putting in a miata tranny since I need a new one anyways, but now Im doing a turbo swap and idk if it can handle the added torque.

 

I don't think the NA miata trans could handle the torque, although I don't know of anyone who has tried it. I am also not sure if the turbo miata gears would fit into an FC case, but it is a possibility.

 

let's not forget what she's here for

 

Lol get rid of the miata and buy a ReX7