Spool or thicker oil in VLSD

[MY1PATH]

hey folks, a buddy of mine is obsessed with his 350z. He's doing a competiton in it next weekend and he wants to lock up the back end just for that weekend and then go back to the factory vLSD when he's done. Since the vLSD works on the pinciple of rotating disc or turbines transfering enery thru a viscous fluid I seggusted running a thicker viscosity oil for the weekend may give him the lock up he's looking for.(mostly I don't want him to blow his $$$ on a spool or mess up his rear end if he doesn't get the backlash on the gears right during the install.) then I read somewhere that the fluid portion of some vlsds is encased seperate from the rest of the differential. So... Will going to a thicker oil for the 350z vlsd work or should he just get a spool? anybody know a good place to get a spool for the 350z?other ideas are welcome be he's a bit stubborn so simple may be better.thanks! and sorry for the long post lol.

[evildky]

the viscous fluid is sealed inside the carrier, when you change the gear oil thats all you are changing, there is no way to ky knowledge to change the viscous fluid in a VLSD

I don not knwo of anyone makign a "spool" for the R200, there are however many other options, hellical LSD, cluthc type, torsen, etc, all of which are more consistant than VLSD, nto sure whn nissan latched on to the Viscous type but most any motorsport requires upgrading to something a bit more sophisticated

[C-Kwik]

It won't do anything for the lock-up. The viscous coupler is sealed as you have heard.

[MY1PATH]

THanks for the info guys, so the viscous fulid is sealed.

So the 350z diff is an R200? whats the interchange with other nissan R200's? are they all the same or are there variations?

my pathfinder has an R200 up front so I may be able to find him a spool or better yet a locker that will serve his needs and be more permenant than trying to sawp diffs every weekend.

[BusyBadger]

What kind of event is taking place where such a strong & quick locking diff is needed?

[MY1PATH]

What kind of event is taking place where such a strong & quick locking diff is needed?

I think its more him than the event and he doesn't have the best luck working w/ vehicles (his 240 was a nightmare) but If I can get him into an ARB locker(made for the pathfinder r200) that can be set to open on the street then he wont have to be switching diffs every time he does whatever it is he thinks the NEEDS a spool for.

[redsx13]

there is no way to my knowledge to change the viscous fluid in a VLSD

You know, im really surprised that no one has tried to do this yet. you would think that one would be able to tap a hole in the side of the actual vlsd mechanism, replace the fluid and then plug the hole.

please correct me if im wrong, but i heard (over on the s-chassis section) that when a vlsd wears out its just the fluid drying up. I have never worked with vlsd's, just open and clutch type, but there has got to be some way to make an old vlsd work, or a new vlsd work better.

[MY1PATH]

Well, he's gonna get an open and wants me to show him where to weld it...I told him he's gonna need a really hot concentrated welder to get good penetration on the side gears(TIG or arc) and that I didn't know how to TIG, Just ark, mig and gass. but I really don't really want to do it but knowing him if I don't he's going to "borrow" a welder and fsk something up....

[hype901]

Get a 1.5 or a 2 way. A spool will be no fun on the street, and the VLSD isn't going to meet your racing requirements no matter what thickness you put in it, IMHO.

[raremotive]

Hmm.... liquid helium, anyone?