I have a 1980 rx7 and i'm wanting to replace the front struts with 1985 units so I can use better strut cartriges and have bigger bearings, but I don't want to change my calipers since I just put new break hoses on it.
so my question is are the 1980 calipers and 1985 calipers identical with the exception of the thread pitch for the break hose? this way I can put the 85 struts under the car with the 85 rotor and caliper bracket and use my 80 calipers. I think this will work from what i've searched but I didn't want to get it tore apart only to realize I over looked something. thanks

 

I just did this on my 81. I checked Rock Auto to compare the part #'s. The 80/85 calipers also appear to be the same. One thing different on the strut tube was the brake line bracket, it's lower on the 85. It will work but the lower line will have a more dramatic bend in it. Cutting the brackets off and welding them back on higher, or swapping the lower brake lines would be the solution. I just left mine with the U-bend for the time being.

 

'80 calipers are the same as '81-85 EXCEPT for the threads for the flex hose. The part will physically bolt up the same but you can't thread the lines from one species to another.

Just one of the many ways in which '79-80 are almost a different generation from '81-85.

I don't know about GSL-SE, but I found that '81-85 calipers will fit the FC single-piston hangers, the only difference is the lower slide pin. I believe the threads are what is different, so you need to use the pin that goes with the caliper. I have a 12A caliper on one side and an FC on the other...

 

Ok thanks that's just what I wanted to make sure of. So on my 80 I'll be running 85 struts, rotors, and caliper brackets with 80 calipers, and rubber flex hoses. Thanks again for helping me double check myself.

 

FWIW, i am currently using an 88 FC caliper on the left front of my 85 GS. the hose threads are the same and its an exact bolt on unit. the dimensions are nearly identical and it works without issue.

 

Yeah SA brake thread pitch is 10mm x 1.5 (maybe 1.25mm) I forget which but SA is courser thread. And that goes all the way through the SA. Hard lines, soft lines etc. FB and everything else brake line wise on the planet uses fine thread 10mm x 1mm. Rubber line not going to screw into hard line without an adapter. RE speed had one listed but I hear they out of biz?

 

Oh yeah info is correct I re read your post. Yeah that will work. Lol it's early for me.

 

Yeah the fb and fc calipers won't do me any good because of the different thread pitch, that's why I was double checking myself that infact the 80 ones will bolt up to the 85 caliper bracket and fit around the rotor. Thanks for the great info though, until now I hadn't even thought to look at the fc stuff.

 

Are there 110 mm bolt pattern front hubs that will fit the 84-85 front spindles?

 

All North American 12A rotors have 110mm bolt pattern. (Some other areas had the 4.5" bolt pattern for all Series 3s, we only got that with 13B engined cars, which they didn't get...)

There are only two different 12A rotors in NA, '79-83 and '84-85. They are all identical in dimension except for the outer bearing.

Just to clarify, no 1st gen has hubs front or rear. Just rotors in the front and axles in the back.