Editing Z31/vlsdInstall php (section)

=== Results ===

After a few weeks of testing this setup, I am very happy with the results. Having a limited slip differential makes the car a whole different machine. It’s much more predictable in hard cornering situations and hooks up much better under hard acceleration.

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Differential noise: Between 45 and 55 MPH a howling sound resonates through the cabin. I attribute this to my backlash setting between the pinion and ring gears. I set the backlash to
'''.009”'''(FSM recommends .005”–.007”). New polyurethane crossmember bushings and diff mount may also contribute. After some break-in, the diff has quieted down a bit. - Shimmed viscous unit: I installed an extra standard-sized (.80mm) shim. At first, the diff was very tight—wheel hop and clunking on sharp corners. After some drag strip runs and more abuse, it loosened up. No more hop/clunks and it remains quick to lock up—actually very predictable.

Overall, I am very happy with the results of this swap.

I believe these methods are among the cheapest and best for attaining LSD capabilities in a Z31. By using junkyard parts, I performed this swap for less than $125.