Subaru LSD in a 240z

[Neal G]

I've searched through dozens of threads on several sites and hundreds of listings on ebay and classified adds and conclude that the Subaru WRX LSD r180 differential might be an option for the 240z. I understand that the spline count is 27 (I believe) on the subie and 25 on the z, nor does the flange on the subie match the Z. Beta motorsports will make a pair of stubs that will "clip" into the nissan 200sx r180 differential and match the 4 bolt 240z half shafts. But they ask for 3 stubs from you to modify. I believe the 200sx diff is a 25 spline and not an LSD meaning you would have to install your own LSD. Subaru WRX r180 diff is a 27 spline w/snap in stubs and can be purchased with a factory LSD from the junk yard in various ratios including 3.9. Now all I need is 27 spline snap in 4 bolt flange stubs. The question I pose for any/everyone is, where can I find stub shafts that go into the WRX r180 differential and bolt up to the 240z axle? Maybe I should just ask where I can get an r180 LSD differential for my 240z? Or am I just really confused?

neal

[five&dime]

I don't know if this helps being that it applies to 510's but there is a ton of useful subaru diff info in here.

Hope it helps.

http://kmhafer.datsun510.com/Subaru.htm#Where%20does%20Subaru%20Fit%20in

[Neal G]

Great site, lots of info. Seems that the subarur 160 LSD works fine, straight bolt in and probably stronger than the r180 open diff. Except the metal dust shields on the stubs would have to be moved inward towards the side seals on the diff. And the r160 is lighter. I may choose to go that way but I'm worried about the extra weight of a z vs a 510/ subaru and I think I'll end up with a Rebello 225 hp rebuild in my car. Might be pushing the r160. If I can stay with an r180 I'll be happier. Even that site warned about stub shaft compatibility.

neal

[rxsleeper]

Take a look at this thread : http://forums.hybridz.org/showthread.php?t=114798

I think you will find a lot of info that will help you.

Paul

[Neal G]

Another great site that help me alot to determine what I want but still no answer about WRX stub shaft/ 240z axle matching. Rather it was here that I discovered the 25/27 spline/ snap in/ bolt in/ r160/ r180/ subaru/ 200sx issues. Someone has got to have this simplified with an adaptor or a source of LSD's for the 240z.

thanks again and keep the refrences and ideas commong.

neal

[jmortensen]

John at Beta Motorsports said that the WRX R180 had a different number of splines on the output shaft, so the only way to use the WRX LSD is to convert to their CV shafts as well. Presumably that would require machining an adapter to the stub axle at the very least, might need custom length CV shafts as well.

You might try Calmini for an R180 LSD: http://www.calmini.com/. I don't know if KAAZ or CUSCO make LSDs, you should check. You can definitely get a Quaife, although they're hyper-expensive.

I wouldn't hesitate to put the R160 behind a 225hp motor in a Z.

[justaZcarguy]

Any more developments on this?

I have a friend that will sell me a r180 3.90 LSD from a WRX Sti, but I am hesitant to purchase it based on converting it - I thought that it was easier that I am reading but need to do a bit more homework...

I have 2 (what I think are r160's), one is a 3.7 and one is a 3.9. however they are both open. That LSD is the better upgrade.

I have an r200 3.90 now, but it's a tad whiny and i need to get it out of there I think soon and get it looked over.

I'll keep looking, if anyone want's to chime in here, I would appreciate it

Thanks!

[CDM]

I cannot speak to the subaru 180 diffs but I can tell you having been a seller of the Quaiffe diffs that they are no longer availible in the US unless more than 10-15 people want to order. I have not heard very much positive feedback on the other 2 you mention but I can tell you that with the vintage race cars we set up and working with an excellent rear end builder we have been very impressed with the new OS giken diffs and were easliy able to modify for the smaller ring gear on the recent 3.90 we did for a street car. Part of the dilema of using an old tired LSD unit is that sometimes there will be no parts to repair them which is why we have told customers to run the old LSDs at tracks that we only run once a year. I would think since the Nissan and Subaru LSDs were both made by Fuji Heavy Ind that maybe some repair parts from subaru could be used to fix the Older tired Nissan units. I know everyone thinks it is too expensive to buy a good unit but remember you get what you pay for and it is a one time deal to build the diff if it is exactly what you want you should never have to mess with it again. The quaiffe was cool because it was torque biasing and warranteed for life and every year you could send it back to them and they would refresh it for a small token fee and I am thinking that the new OS Giken is the same price range and the reviews have been outstanding and of course replacment parts should be availible for a long time to come.

Just so there is full disclosure I am so impressed with the Giken products that I have become the dealer for their products but that being said I have to say I would be doing my customers a big diservice by having them pay several times for the same service to rebuild or change diffs. We have been very fortunate to find a good setup guy and have built over 20 diffs in the last 4-5 years some for street and some for race. Remember done right it is a one time investment for a good diff.

[John Coffey]

If you want a Quaife diff, call Taylor Racing. They have them on the shelf for the R180.

OS Giken is making a 25 spline Super Lock CLSD diff for 115mm ID ring gear R180s and I'm also a dealer for them. Should be four or five available when the boat gets here near the end of the month.

I'm also in the process of machining 27 spline side shafts for the 2004 through 2007 WRX STi R180 that will bolt to the stock 240Z halfshafts. I have a SCCA IT customer waiting to install them in the 240Z and run a couple races to test things for me.

Edited June 17, 2009 by John Coffey

[John Coffey]

And to echo what Les/Dennis posted above, the OS Giken Super Lock is probably the best diff I've ever run in a race car. I have on the in back of my 350Z. They are shipped from the factory with a "Spec S" setting of 100% lock under full torque. The rate of lockup is completely adjustable with springs.