i think my diff is broken

[Ghostrider]

Ghostrider-do you know the specs of an HR31 R200 LSD? My diff has not been tightened,that I know of,and it will rotate both wheels,under any circumstances from a standing start,or low speeds....

Open wheeling round medium speed corners,or when the rear is under a lot of body roll,is a different matter though.........

It's about the same I believe. As you say you have mixed results with yours which is the problem, with such low preload, the harder you make it work the easier it will release.

[rsx84]

what your saying is a standard lsd is good for just that, if you want it to work well with more power going to it then a rebuilt to get a high preload is the call...

[Ghostrider]

Near enough!

Matt,

From my research, Cusco was the prolific a/mkt diff centre supplier of our cars era, Nismo got involved more into the HR31 era, but unless you had either of these, you don't have much better than an open diff as it sits standard.

It was more a selling pitch as I said before.

Look at today, all the new cars have viscous LSD's, but the serious guys are still fitting mechanical LSD's. Bet you don't find many viscous diffs in the WRC, but all to most of the cars sold to the public had them stock.

You will have to find a good motorsport guy/mechanic, find a Datsun Rally workshop up there, someone that's been playing for years with 1600's and the like, they will have all the guts on them.

Good luck.

[V8skylineMAN]

I have 3.9 & 4.1 and looking for a 4.4 R200 for my arsenal, as the so called experts say 4.4 is the right diff for Wakefield Park

i know the r180 is not as large but if you get the front diff(r180) from a nissan 720 4WD the ratio is 4.89.....i used this in my datto 1600 for many years and it is an extremly tuff center...the crown wheel is a heavy duty one as it is for off road and IIRC the planetary shafts are bigger too...

as you know, the r180 also came with a cv joint driveshaft configuration so it would probably be worth the effort just to see if the ratio is what u are after....

btw the 1600 still had a top end of just over 200km/h so its not tooo low....and that was a 2.2 litre l20b stroker(not the highest reving engine)

[0HR-30T]

It's about the same I believe. As you say you have mixed results with yours which is the problem, with such low preload, the harder you make it work the easier it will release.

Hmmm,fair enough.I thought the '31s may have had a bit more preload factory,cause as I said,low speeds or in a straight line,it's sweet.....with my RB20 in front of it anyway. I'm not planning much hard cornering/circuit use,so I'll leave mine alone till it starts complaining

[BensDR30]

I would not be in any great hurry to put a 4.375 ratio diff in a DR30 (actually yours is the RB20 HR30) . I tried that with my FJT Bluebird (4.375 H190 LSD) and found minimal gain and lots of revs for no good reason on the highway . I always found myself trying to change from 5th to the non existant 6th . The lowest I would go is 4.1 and often wish my RSX had a 3.7 . The RB26/31 will prefer it .

 Cheers  A .

I'm not 100% sure who you're replying to there (if indeed it is a specific reply ), but the HR30 is (originally) an L20A not an RB20 and the DR30 with a 3.90:1 is not 100% happy in 4th@60km/h. The option 4.11:1 is certainly a more suited ratio for around-towning.

I have no concern for highway rpm's in my DR30 - that's what the Stagea is for, and I only have 3.90 & 4.375 LSD's so the 4.375 is going in. I'll certainly provide feedback on the success of the conversion in regards to city driving, power delivery & economy when it's done.

Ghostrider, I might be able to find you a 4.375 R200 LSD - I'll get back to you.

[Doctor 30]

So now that I replaced my diff oil with penrite something I did it all for nothing? It has to at least assist getting the thing moving in the wet where relatively low amounts of power are required to get 1 wheel spinning, doesn't it?