Breaking the Z in and have a question about the LSD

[dat240zg]

I've put around 100 miles on the Z now that it's mostly done and have a few questions that I need to ask. I've searched, but honestly don't know the right terminology.

 

The car is equipped with a Nismo R180 LSD that has the more aggressive ramps of the more common R180 LSD rear ends.

 

What has me raising an eyebrow is the way that the car doesn't like to turn at slower speeds. I've heard of aggressive, but this feels more like the rear is welded (it isn't). If you saw my driveway, it looks like I've been peeling out every time I leave or pull in. It's laying rubber all the time!

 

It locks hard enough that when turning tightly, the outside wheel will try to turn backwards. When backing up and turning (like pulling out of the drive), it feels like the rear is binding up.

 

Anyone care to share any insites? The rear definitely helps when getting on it at speed - there are two nice fat lines at a nearby stop sign and I feel confident getting into the power when going through higher speed curves.

Just feels weird at the other times.

 

Bryan

[JMortensen]

I'm a bit confused by "the more aggressive of the 2 common rear ends." Can you clarify that?

 

If it is the typical LSD chatter, you just need to add LSD additive. They're all the same, whether it's GM or Chrysler LSD additive or Ford's "friction modifier" or any of the others. That will get rid of the problem. Without additive a tight LSD will make some hellacious noises, banging and popping.

[dat240zg]

Jon:

 

I was just referring to the more aggressive/less aggressive ramps. I went back and edited it for clarity.

 

I'll give the LSD additive a shot. Right now there's only Royal Purple gear oil in it.

 

Thanks for the insite.

 

Bryan

[Clifton]

Have you checked the break away torque? It sounds like it's pretty high. When I ran a welded diff it was as you described.

[johnc]

Nissan Motorsports did sell two different ramp styles in their LSDs to allow a small option in the locking progresion. I ran the more aggressive version (essentially 100% lock) in my BSP 240Z and backed the preload down to about 45 ft. lbs. Low speed, sharp, low engine torque turns will essentially have the unit locked. Putting a couple hundred miles on it with a couple bottles of Torco friction modifier helped. If you can find a parking lot and do 30 minutes of figure eights after adding the friction modifier you can really speed up the break-in process.