The 510 Realm

Hi guys,
I'm new to the Datsun world and am beginning a new project 510 4 door for my wife.
I have an opportunity to purchase a R200 diff from a 240 sx.
Would this be a good upgrade and what extras would I need to look at?
Thanks for any input,
Rob

That is a really big, HEAVY diff, and unless you are going to make some huge torque, I would suggest sticking with the R-180 diff. There are a bunch of us on here making upwards of 260 - 300 Hp to the rear wheels through a R180 with no issues.

Regardless of the overkill-ness (which is likely true, unless your wife is Michele Mouton?), the R-200 used in the 240SX is the short-snout type - it won't bolt in without extensive mods. The R-200 used in some of the 280ZX and 300ZX is a long-snout type.

http://www.the510realm.com/viewtopic.php?t=22269

Thanks for the input guys.
The car will have approx 400 hp at the crank and will be used for auto cross, some road race along with street driving.
Just want to make sure that things are over built instead of breaking things.
Sounds like a diff from a 280 or 300zx is a better idea.
What years, etc. should I be looking for?
Did they make a posi unit?
Should I look for one from a turbo car?
Thanks,
Rob

Mid 87-89 300zx turbo has a factory 2 way lsd. Very rare but you could find. There are clip in stub axles with 4 bolt flanges than can be had from a 280zx.

After mid '86 model year, ring gear bolts were 12mm. This means that a late 86 turbo would yield a 3.545 with 12mm RGBs. 87-89 turbo is 3.7 LSD, 87-89 NA z31s are 3.9 open. One of the 80s 200sx turbo cars came with a 4.11 open R200. Also very rare.

You can take an s13 29 spline aftermarket LSD center and swap it into the post 86 long nose easily. Earlier units can take the same units as well but the M10 ring gear bolts should be sleeved to suit the M12 holes in the newer LSD units.

I would just purchase a used 2004-05 Subaru Sti R180 diff and call it a day. Easy to find and install and strong enough to handle the level of power you are going to be putting down. Might want to consider upgrading to CV axles at the same time though.

Thanks for the input Ryan.
Like I said, these are new to me. Is the Subaru R180 a posi diff?
What's the difference between the Datsun R180 and the Subaru unit?
There is nothing wrong with the unit in the car now but I just want to make it as bullet proof as possible.
Is it possible to make the original 1970 diff a posi without to much hassle?
Thanks again,
Rob

You can turn the stock open diff to a LSD or you can just find a Subaru R160 with an LSD. The are the same except for the pinion flange and axle stubs. I have a Subaru LSD with 4.44 gears. The axle stubs from your stock diff will bolt straight in and I just had to shave down 2 sides of the pinion flange so it would slide into the rear crossmember without having to remove the crossmember. I think the LSD R160 with 4.44 was in a Forester. I'm not too sure of the year but it is not hard to find out.

vetteguy22 wrote:Like I said, these are new to me. Is the Subaru R180 a posi diff?

Sube R180s are posi, but the type of LSD varies with the years. Some prefer the clutch-pack versions, some like the Torsen. A couple good threads here talking about the differences.

vetteguy22 wrote:What's the difference between the Datsun R180 and the Subaru unit?

Datsun units are rare, and old. Subaru's units are newer, more available, parts are easier to find, and you have choice of LSD types.

vetteguy22 wrote:Is it possible to make the original 1970 diff a posi without to much hassle?

DQ Volume 10 Issue 1 - Tech How-To: R160 Differential Rebuild, Part I -- R160 differentials dont often need service or a rebuild, but when they do, where do you go to find that information? In Part I, Derek Garnier shows how to disassemble your R160 and R160 LSD and also reviews the steps necessary to convert to 4.11 gears.

DQ Volume 10 Issue 3 - Tech How-To: R160 Differential Rebuild, Part II -- In Part I, we finished with a fully disassembled, cleaned, and painted differential housing along with a fully disassembled and cleaned (and possibly machined) center section. It’s now time to inspect our parts, order bearings and seals, reassemble, and adjust the differential.

Thanks guys,
That's some really helpful info.
I really appreciate it.
Rob

DQ Volume 12 Issue 4 - Tech How-To: Installing an '06 Subaru STI-R R180LSD — Beta Motorsports 27T stubs create new possibilities. Accessorize your new differential with a Perrin large-capacity diff cover.

I second going with the R180 out of the Subaru with the Beta Motorsports stub axles ( Sold by Futofab.com now right ? )

PoorMtnKid wrote:I second going with the R180 out of the Subaru with the Beta Motorsports stub axles ( Sold by Futofab.com now right ? )

Yup, STi conversion stub axles are in stock at FutoFab, $550/set.
http://www.futofab.com/index.php?option ... Itemid=122

FutoFab has made some upgrades from the design Beta Motorsports / Wolf Creek Racing sold.

We now make our STi Conversion stub axles out of forgings, not cut from billets as was done in the past. Also, only the shaft is heat treated for surface hardening. If the entire stub axle is heat treated (as done in the past) the flange becomes brittle. The heat treating penetrates to a depth of roughly .250". The flanges are so thin that the heat treatment fully pentrates the material making it brittle. On the shaft the core of the shaft remains untreated which gives the axle some added flex to absorb the shock loading driveline parts are subjected to.

Our forged STi conversion stub axles are easily identifed by their round flanges.

Just to continue this conversation about R200s.
Does anyone have first hand knowledge about the conversion?

I am currently looking at 2x 3.9 & 2x 3.5 disassembled long nose diffs
And
a variety of disassembled short nose.

On the short nose ones they have a 8mm space on the left side and on the long noses it is on the right.
If you have had one apart you will know what I mean. Now because of this I have no idea how people mate a short nose LSD center into a long nose casing.

It would put the center in an 8mm offset in the wrong direction and mess up the inputs circlip position.

Does anyone have any further insight into this?

I've been there done that. S13 vLSD into a 3.9 z31 NA long nose r200. I kept the original long nose spacers and shims on the carrier. Swapped the long nose ring onto the vLSD carrier and reassembled. Didn't check backlash etc but it all felt fine. Certainly not 8mm out. I did not mess with anything on the pinion.

Maybe I'm misunderstanding the question but I hope the above helps? Post some pics of what you find and maybe we can help?