thegemini

Should I look for a used turbo or GTUS LSD. Or would I be better off with a aftermarket.
Is this a realative easy upgrade?

Rxmfn7

iTrader: (4)

Run a search on here for LSD, there is a good amount of info available. Also in the "FAQ for FCs" at the top of this forum, there is a list of what models came with LSD stock. S4 (86-88) cars came equipped with a clutch type LSD. S5 cars ( 89-91) came with a Viscous (fluid type) LSD. The advantage of the S4 LSD is that it has a very quick lockup rate, but can/will wear out over time. The S5 LSDs lockup rate sucks, but it will last pretty much forever. The N/As use a 7" ring gear, while the Turbo2 uses a 8" ring gear. Therefore, swapping just the LSD from a T2 to a N/A, or vica-versa, is not possible. You could however, swap in the entire Turbo2 rear and and axles, but would then either need to use the T2 tranny/driveshaft, or have a custom driveshaft made up. The only advantage to this is that the T2 driveline is much stronger, but on a N/A car, that strength is not really necessary, and just adds extra weight. You can also swap the Torsen (TORque SENsing, or gear-type) LSD from a 94+ Miata into the N/A rearend ( I did this, search under the archives under my name for the write-up) , or the Torsen from a FD into the Turbo2 rear end. Torsens have almost immediate lockup. The only disadvantages of these types, is they are more prone to breaking under high power than a clutch type, and also if a wheel lifts off the ground, it gets all the power due to the way the torque biasing works on them.

I would suggest finding a used S4 N/A LSD rear end ($150 ish), and swapping that in, instead of just swapping a LSD unit into your rear end.