I read the FAQ but am my question still hasn't been answered. My understanding is that my '87 NA came with an open 7" ring gear, and I would really like a decent rebuildable clutched LSD for racing. Finding a 2nd-gen NA lsd has proven to be difficult, but 1st-gen lsd's appear to be fairly common. Can anyone confirm or deny that they fit or don't fit for me?

If this has already been answered, please link me to wherever that answer is. I was unable to find it, and I'd prefer to encourage 'good forum etiquette' with a single source of truth than to answer the same question multiple times in different places.

 

I'm interested too. I have a GSL-SE diff and an 86 RX-7 that I would like to equip with it. Does it fit?

 

It sounds like you have everything you need to find out.

 

Sounds like you both have the parts needed. Take lots of pics, or better, yet make a decent video and verify it. ;-)

You beat me to it, lol.

But yeah according to these guys, YEUP-it does.
http://www.solomiata.com/Drivetrain.html

 

I was going to put an '85 diff into my '89 n/a car.
I didn't end up doing it because I got a good deal on a Kaaz unit.

That being said I did research it, I don't see any reason why it wouldn't work:

As far as the diffs being the same internal size:
Kaaz has the same part number between 84-92 na diffs: DBZ1810
Diff Mount, LSD, Torsen, Rear Oils

Secondly, I was worried there wouldn't be a groove for the stub axle circlips to attach to from the solid axle car. (The Clip-rings that hold the independent axles into the diff)

That is not the case as shown in this thread where a miata owner puts an 85 diff into his 1.8L miata rear end, it is pretty common knowledge that the N/A FC rear end fits into the 1.8 diff housing: https://www.rx7club.com/1st-generati...thread-815576/

 

I have some reading to do, it seems. I've found a bit of anecdotal evidence that the s3 LSD fits the n/a s4/s5 housing, but I'm not sure how much money I'm ready to invest in the investigation process. Hopefully I'll uncover enough facts that I can take action soon.

 

Don't seem "anecdotal" @ all to me.. Go for it!

 

That's good enough for me. s3 clutched LSD is on its way here. As soon as some of the snow melts, and the snow banks are lower than the roof of the car, I'll drive it down to the shop to try plopping it in. I'm curious as to whether there are any substantial differences with regards to the ring and pinion, most pulled lsd's don't include them so I'll likely have to reuse the n/a one I have or order a new one.

 

Get video/pics!

 

I'll get photos and measurements as soon as it arrives (just marked as shipped). I'm really hoping the s4 n/a ring and pinion fit in the s3 carrier.