Settling on two rear end options...

[AydinZ71]

Hi! I’m trying to settle on two options. Not exactly apples to apples, but I’m focused on comparing difficulty is sourcing parts and torque capability vs weight drawbacks. Of course price is a consideration. Open to others, but so far this is what I got:

 

1) wolf creek racing CV shaft conversion with an R180 Subaru lsd

 

2) techno Toy tuning rear end kit for a r200/230 lsd sourced from various donor cars

 

what are your thoughts? Option one is significantly cheaper, but I will be stuck with stock wheel hubs. Also not aware of the torque limitations on the Subaru lsd’s. I don’t see my plans ever exceeding 450lbs of torque.

 

 

[sareld1]

 

[Ben280]

It really depends on what you plan to do with the car. If you want to cruise around, enjoy some spirited back roads and don't want to break the bank, the R180 is probably the better of the two options. The factory stuff will work just fine unless you've swapped the motor. 

 

If you have a R200 now, you could just swap in a new LSD center section, do the Wolf Creek axles and have a pretty reasonable setup. 

[NewZed]

7 hours ago, AydinZ71 said:

Hi! I’m trying to settle on two options. Not exactly apples to apples, but I’m focused on comparing difficulty is sourcing parts and torque capability vs weight drawbacks. Of course price is a consideration. Open to others, but so far this is what I got:

 

1) wolf creek racing CV shaft conversion with an R180 Subaru lsd

 

2) techno Toy tuning rear end kit for a r200/230 lsd sourced from various donor cars

 

what are your thoughts? Option one is significantly cheaper, but I will be stuck with stock wheel hubs. Also not aware of the torque limitations on the Subaru lsd’s. I don’t see my plans ever exceeding 450lbs of torque.

 

 

 

You're covering a really wide range here.  Including wheel hubs with your discussion of differentials.  Talking about up to 450 ft-lbs of torque.  That is a huge amount of torque.  The R180 won't handle that if you get sticky tires and try to use it.  The Ford diff setup is more appropriate for big torque but is a fairly extensive amount of work.

 

As Ben280 says, it depends.

[seattlejester]

As others said depends on your use. You could have 1000ft lbs, but if you have it set with boost by gear and traction control along with a clutch damper you could run that pretty long term. If on the other hand you are on the stock setup with a pucked clutch and drop the clutch on drag slicks something will give real soon.

 

I was in the high 300, low 400 territory with CV axles on 280z stub axles. It handled some low speed clutch kicking on thinner tires, but I'd be hesitant to try anything that aggressive with slicks or much stickier without revisiting at least the stub axles. 

 

You're loading the discussion as well with talks of budget. R180 Subaru LSD with stub adapters and wolf creek axles can be anywhere from $500 to $2000 depending on how good you are at deal hunting that still leaves you with the stub axles and an R180, not to mention the axles and joints are not immune from failure. T3 setup also starts at $3400? but depending on the condition of the parts and options that can balloon out much more. 

 

If you plan on putting 450ft lbs to the ground repeatedly and with vigor the stock stub axles will not like it very much. The lighter options from the T3 will also struggle depending on how much weight/grip/activity it sees. Drifters break the R200 setup from the 240sx all the time at much lower levels. That moves you to either sourcing the R230 setup with TTT or going to the ford 9 inch setup.

 

I wouldn't hesitate to run the stock setup for quite a while. The rear end is pretty easy to remove and the stock setup will put up with a good amount of use as long as you use the clutch on take off and keep shock loads down. 

[Ben280]

Seattlejester makes a solid point about tires. I've broken u-joints in the factory shafts at 230ft-lbs on big ol sticky tires. Drag launches and clutch kicks are what break diff parts, so as long as you stay away from that, and lower than your 450ft lbs, the smaller diffs will be fine. 8.8/9.0 Ford diffs and R230's all require some level of fabrication to fit. 

 

The easy move here is to keep/get a R200 rear end, and put a LSD build for a s13 open diff in, and then buy the Wolf Creek CV's. That's my setup, and it's held up amazingly well. With this option, you don't have to source the Subaru to Datsun adapter stub shafts, or the increasingly annoying to find Subaru R180's. There are a couple threads on here about using the OBX helical diffs if you want a real cheap solution, but you can also just leave the factory diff alone, and add in a LSD later if you aren't sure you want one now. 

 

Some more info about your goals would be instructive here and we could give you a better answer!

[JMortensen]

Agree with Ben. It's all about the tires and the launch. If you're drag racing, spend the money and go 8.8 (I'd do that over 9 or R230). If not, the R200 is probably good enough but you really will need the chromoly stub axles to finish it off, at which point, you're coming pretty close to the cost of the 8.8 swap.

[AydinZ71]

First off, I want to thank all fo you for your diligent consideration, information, and opinions! Really appreciate it. 
 

I admit I convoluted the situation by introducing so many variables. Let’s set cost aside for now since that is a personal decision somewhat disjointed from technical aspects.

 

i agree with all of you that impulse (force/time) is ultimately what breaks things. Even low torque “slammed” onto drivetrain  components at a stand-still or at high speed, will break stuff.

what is driving my interest is the clear need for an LSD. In that pursuit, I don’t want to make an investment that may break early.

 

My plan: The 71’ i recently purchased is a former regulation SCCA race car. It has a full cage, fuel cell, and stripped down to essentials. I want to keep it as a car worthy of a track, but not interested in keeping the “stock” class (currently has SU’s, non original L24, 4 speed). It will not be daily driven. I live at the foothills of Angeles crest here in Los Angeles, so most of the time it will be mountain/canyon carving. Hence, acceleration and cornering will be key, but not top speed. It’s just too dangerous to speed on these roads, but hard acceleration and deceleration into visible turns is what I need. 
 

I will not be launching from a standstill often, and even less so “dumping” the clutch on sticky tires. I will however be putting all that torque on and off the drivetrain repeatedly. 
 

when COVID is in our rear view, I would like to return her to the track, but I doubt I will be racing competitively. 

 

i say 450lbs max, but that’s really way in the future. I’m currently considering everything from an SR20det for the weight savings, to an RB26 because it was my childhood dream. I will probably keep either engine stock in the short term until the brakes and drivetrain catch up. 

 

i built an L28et running 16psi and ~300lbs of torque back in 2002. I had an open r200 and obviously struggled with traction The instant she hit boost. 

Edited August 14, 2020 by AydinZ71

[Ben280]

Now that you mention the car, I do remember seeing photos in another thread here! I'll have to file your username away as one of the good ones  

 

I think a setup similar to mine (3.90 R200 from a 280z, S13 Kaaz 1.5 way and Wolf Creek CV's) will be good to get rolling and have the benefits of a LSD right out of the gate. Chromoly stub axles like @JMortensen mentioned will be a good upgrade, but not IMO strictly necessary for your first round of mods. 

 

The Subaru conversion has it's fans, but with how easy it is to find R200/S13 parts I think it's overrated. 

[AydinZ71]

I appreciate that! Very helpful! 
I do see them on eBay often. They seem to be anywhere from 1 way, 1.5, and even 2 way clutch LSD’s? 
 

how would I replace my current diff center section? Machine shop? 

[LooseRocks]

I would think that any transmission shop that's reputable would be able to do that type of work.

[JMortensen]

If you're even moderately good with a wrench you can install an LSD. The tough part about differentials is setting pinion depth, and you don't have to get into that at all to put an LSD in. I did a write up on it:

 

[JMortensen]

As to the different "ways":

1 way works on accel only, does nothing on decel. Usually found on FWD cars.
1.5 way works full power on accel, does a little on decel. Good for road racing, autox, canyon driving.
2 way works equally on accel and decel. Good for drifting, road racing, etc but going to be looser than 1.5. 

1.5 way is the best choice, that said the Nissan LSD is 2 way and I've been using them forever for autoxing. Would rather have 1.5, but not worth it to spend the money and change it out for me.

Be careful out there. Canyons are unforgiving. 

[Ben280]

2 hours ago, JMortensen said:

If you're even moderately good with a wrench you can install an LSD. The tough part about differentials is setting pinion depth, and you don't have to get into that at all to put an LSD in. I did a write up on it:

 

 

Good write up! So long as you don't mess with the gears, it SHOULD be a simple job. Double checking the backlash is a great go/no-go check and to make sure you have the shims on the bearings in the same places. 

 

I would add that with the S13 "open" LSD you will need 12x bushings to get the long nose ring gear bolts to work with the LSD center section. I'm pretty sure the ring gear bolts in a 280zx R200 are 10mm, and the holes in the S13 LSD are 12mm. McMaster Carr or your local hardware store should get you sorted! 

[NewZed]

 

[caperix]

What about using the t3 uprights for the newer bolt in wheel hearings with the long nose r200?  That would get rid of the weak link stub axles and let you use cv axles with out adapters.  Apex used to list a similar part on their website, but I no longer see it separate from their full rear setup.  I don't know how much just the uprights would be but I would think it would be cheaper than chrome molly stub axles & cv adapters.

[AydinZ71]

2 hours ago, caperix said:

What about using the t3 uprights for the newer bolt in wheel hearings with the long nose r200?  That would get rid of the weak link stub axles and let you use cv axles with out adapters.  Apex used to list a similar part on their website, but I no longer see it separate from their full rear setup.  I don't know how much just the uprights would be but I would think it would be cheaper than chrome molly stub axles & cv adapters.

 

I like that Idea! I will get a hold of them and ask them to quote. I like how well thought out the stuff on their website is, but like most CA suppliers they are super expensive. If these were made in Houston, I am certain they would be 30% cheaper. It could also be that competition is dwindling due to low sales volume. 

[AydinZ71]

8 hours ago, JMortensen said:

As to the different "ways":

1 way works on accel only, does nothing on decel. Usually found on FWD cars.
1.5 way works full power on accel, does a little on decel. Good for road racing, autox, canyon driving.
2 way works equally on accel and decel. Good for drifting, road racing, etc but going to be looser than 1.5. 

1.5 way is the best choice, that said the Nissan LSD is 2 way and I've been using them forever for autoxing. Would rather have 1.5, but not worth it to spend the money and change it out for me.

Be careful out there. Canyons are unforgiving. 

 

 

What do you think of this unit?

 

https://www.ebay.com/i/233389417734?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=233389417734&targetid=934800884536&device=c&mktype=pla&googleloc=9031107&poi=&campaignid=10763469106&mkgroupid=109143657034&rlsatarget=pla-934800884536&abcId=9300385&merchantid=6296724&gclid=EAIaIQobChMIpM_cxOSb6wIVxx-tBh3YtAITEAQYBSABEgKRAPD_BwE

[AydinZ71]

5 hours ago, NewZed said:

 

 

I recently did a TON of reading on the various types of LSD's. It looks like the "clutch" type is the most aggressive to prevent wheel spin when you are on/off the gas repeatedly. That seems to be the reason it is favored by the drifters. If i understand correctly, the helical come second. it is in the family of "permanent" LSD's, but is more aggressive than a viscous unit. So much to learn. 

[AydinZ71]

8 hours ago, JMortensen said:

If you're even moderately good with a wrench you can install an LSD. The tough part about differentials is setting pinion depth, and you don't have to get into that at all to put an LSD in. I did a write up on it:

 

I have a local shop that says they will do it for $150 bucks. I might just take the diff and carrier unit with me to them. If i could speak to you more about checking "backlash", i might have more confidence doing it myself. I may be misunderstanding your directions, but do I need a press for the bearings and a quality caliper for measurement? if so, i have neither at the moment :/ 

 

I have certainly installed and removed my fair share of R200's on S30's. PITA without a lift, but i can manage.