Ratio: 4.07
Format:
Part Number - Revision
Pinion Markings:
090 B
Ring Gear Markings:
L(?)3M090 k
L(?)3M090

 

Ratio: 3.93
Pinion Markings:
A8
M050 C
Ring Gear Markings:
A2 M050 G
A2 M050

 

Ratio: 3.90
Pinion Markings:
805 B 1E
Ring Gear Markings:
C1 8088 AD
C1 8088

 

Ratio: 4.77
Pinion Markings:
Ink- I2226
Ring Gear Markings:
N4 DH1
Ink- 1Z 2226E

 

Thank you! if it isn't already known, the stampings actually refer to the part number, which is nice!

 

Thats incredible that you took the time to take the differentials apart, clean them, identify each and create this post! Thank you! This will definitely be very helpful to many people in the years to come!

 

Thanks J9!
Happy to help, I ended up with one of each by chance. Have to give credit to 82transam for collecting these things for his drift days 👍 I got lucky and happened upon the 4.07

I'm now building two clutch stacks, a 3.93 for myself and the 4.07 for him. Managed to get both our stacks to match the core clearance of .055mm exactly to Steve's. If there's interest, I've been taking pictures of my jigging and measuring methods and can eventually add that document to his archived thread.

Add another GSL LSD core tear down and the FC open diff on top of this and you can see why the pictures of the r&p were on the floor.

For the inner engineering nerd in all of us...

 

Nice job on the reference thread. Glad that old stuff actually was actually useful lol

 

You can also use the Miata 4.10 ring and pinion in the gsl rear axle. They cheap and easy to find.

 

4.30 Miata ring and pinion is an option. Easier to find than a 4.44

 

Speaking of Miata's

Here's something I found on a miata site when looking into swapping over a big bearing LSD clutch center into my torsen 94 NA miata.

General info on transmissions and speedo gears too.

 

the 94-2005 miata has a diff that works in the FB, its the same axle size as the 84-85 cars.
94-97 NA, used a 4.10 diff, Torsen was the option
99-2005 NB automatic is 4.10, no limited slip on an automatic miata ever.
99-2005 NB 5 speed, is a 4.30 type II Torsen is the option
99-2005-NB 6 speed is a 3.9, same limited slip as the 5 speed.

the 1990-1993 cars used a different diff, the T type and are not compatible

 

The torsen LSD are getting hard to find and expensive. All the Miata and rx7 guys want them.
I got a 4.10 ring and pinion from eBay for $100 and it looked new.

 

i'm not sure its that great, its just the least expensive option

 

Have to agree with that sentiment, with my turbo miata, anything above the torsen torque ratio limit, it behaves exactly like an open diff. One tire fire, single leg burnies, what ever you want to call it. Wasn’t consistent on which tire would spin either. Great for street and road courses. Not so much for autox, drift attempts or being an idiot on a dirt road.