Hi,

I'm converting a 4-bolt to a 5-bolt with an LSD and would like to know are the drive axles different between the models?

Also, what if any parts are common between the FC and Miata?

Thanks,

Mike

 

With respect to the RX-7 LSD and driveshafts (halfshafts), the non-turbo parts are the same, and the turbo parts are the same, but the non-turbo parts are different from the turbo parts. If you are looking for junk yard parts, you will need to take a caliper with you because the parts look very similar. The shaft is easiest to measure if the part is still attached to the car. Turbo is about 26.35mm diameter, while non-turbo is about 24.20mm diameter. If the shaft is off the car, I think it is easier to just look at the thickest round part of the shaft near the square flange. Turbo is about 88.5mm and non-turbo is about 82mm. ISC Racing does a good job of rebuilding:
http://www.iscracing.net/2nd_Gen_Parts.htm

I know that some Miata parts interchange, but I don't know which ones.

 

You can run the 4 lug axles on your Five lug LSD Mike.
just have to do some rearranging If you decide to Upgrade again and put a TII diff in there.(you need Tii halfshafts and the Tii diff and the Driveshaft too).If you need some info,and feel Like Pm'ing me.Go right ahead.(msn is Misterstyx69@hotmail.com..can chat there too.)Cheers.your AFm Is Enroute!.