Differential Question for a 280zx

[2126]

Just a note regarding the spacers to fill the gap when installing R200 ring gear with 12mm through hole and using the 10mm bolts. Give Precision gear a call, as I did, and they will tell you they are not necessary and have customers who race off road who have no issues by not using these spacers. Basically, if you are worried about the ring gear slipping against the LSD carrier, them you have not torqued the bolts properly. Also, if by chance you fabricate spacers that happen to be a tiny bit too long, the bolts will not clap the ring gear properly and you WILL then have a problem. Don't trust my post, call Precision Gear! I've got one of their R200 LSD and it works perfectly and it cost under $500.00.

[JMortensen]

inismo gt lsd 700$ "way different design on the new nismos from the old ones' date=' more clutches beefier parts and much more brake away torque,locking pressure"

nismo gt lsd pro 900$[/quote']

If you look at my thread on shimming, you'll see that my diff had WAY less than the advertised breakaway. Then another guy racing a roadster bought a Nismo diff and it too had the same ~15 lbs breakaway. There was another recent thread where bjhines had the "other" LSD, which did have a different better clutch pack, but I don't see how one can be distinguished from the other when ordering. After all, the roadster guy ordered the Nismo part and ended up with the crappy one.

 

As to the spacers, I still feel better having them seeing as how the R200 is the only diff I'm aware of where the ring gear is not a press fit on the carrier. If you torque down the ring gear bolts and use loctite nothing should slip, but for the $20 I spent I feel it was worth it just for piece of mind, especially for a car that does a lot of full acceleration to full deceleration with no in between, and on slicks on asphalt.

[2126]

Come on now Jon, I didn't mean to get ya going on the spacer deal! I just wanted to let guys know that Precision Gear themselves told me this when I asked them the question.....just passing along some info.

[driftz240]

i think some companys rate brakeaway torque dry "no oil" diff new sitting on a bench."but i gould be wrong"..also sometimes they get more grippy when they get to operating temp". also on the new nismo gt lsd I belive the clutches are 20% larger than the older nismo units, if im reading my japanese correctly, im forgetting alot of my reading skills.

 

you can definetly get more agressive with clutch arangment, and shim size, its somthing you really have to play with to get right. kazz units for the r200 usually come with 80% lock up, and so much brake away torque they hop the inside tire in tight, very low speed corners "makes people think you forgot to tighten somthing down". you can call kazz and have them get you one for the 12mm 10 bolt r200 carrier, 29 spline .

[JMortensen]

Dry torque on mine I would guesstimate in the 80 lb range. Wet torque... ~12 to 15 lbs. I've never heard of them getting "more grippy" with heat. I have heard of racers having the LSD slip at the end of a 30 minute sprint race. It seems our info is contradictory on this one. Here is my primary source of info on the Nissan LSD: http://www.gordon-glasgow.org/lsd1.asp and above and beyond that I've gathered info from people who have used these things for years in race cars, like katman, Savage42, and others.

 

Tom- I hear you man. I do think it's worth noting that every other diff I've seen put together has had to have the ring gear beat onto the carrier with a dead blow hammer, except our R200. That lack of a press fit is a good reason to be more concerned with the bolt size. I admit I may be overly concerned with it, but it isn't without any reason at all.

[driftz240]

"not hot"... they will slip if you get them smoking azz hot, like after a good hard session of abuse. but the clutches grip better at a operating temp, kinda like brakes , hawk hp+ pads suck on the first few stops but get better when they get in an effective operating heat range.. that might be why the lsd units seem to have a lower brakeaway torque sitting on a bench at room temp rather than at operating temp...im no differential engineer, ill ask a friend at TRD south and see how they rate brake away torque...hot , cold, wet , dry?..now i really want to find out..as well as how to properly check it without the fancy tools,"im not sure if the old jack one side of the car up and make up a bracket to fit the lug studs with a 7/8 nut welded in the center of the bracket,and pull and look at the torque wrench to see what torque you here the clutches slip trick works accuratly..

[Guest ModToad]

Just a bit of info here ...

 

Watch the '84 and previous 200sxs, they had the H190 solid axle, not an R anything.

 

The non turbo 200sx 85-88 were all R180s.

 

The 84-86 turbos are R200s 10mm

 

87-88 VG30 (200sxse)

 

87-88 turbo (canadian models only) R200 12mm

 

Heh ... I have a couple of each. All 200SX differentials are the long snout case (like Z cars, not S13/14/15).

 

The Subaru R180 LSD swap is possible, it's just not a straight forward affair. There was a link on my old S12 board about it. I never had an R180, so I didn't read too closely.

 

Also to figure out differentials and ring and pinions

 

Look at the plate stamped in the engine bay. Under TRANS/AXL

 

there will be a letter code/number

 

My brain has stalled at the moment, but I know on my 87 200SX, the code is RC41

 

which is R200 with a 4.10 gear set

 

I believe RB is the designation for the R180. The number that follows is always the ring and pinion ratio.

 

Just curious where you are getting the pricing for the Power Brute? It's mentioned as $600, or "got mine for under $500"

 

Jobber rate?