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AydinZ71

Settling on two rear end options...

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Checking backlash is simple but requires a dial indicator and magnetic base. You stick the base somewhere on the housing and aim the dial indicator at one of the ring gear teeth, perpedicular to the tooth face, then you just rock the carrier back and forth and watch the gauge. Good idea to do it in 3 places around the ring gear after as this also double checks that you have the ring gear on the carrier straight.

I've never tried, but I'd bet you could get the bearings on with a hammer and a socket if you didn't have a press. Or, $150 is pretty reasonable cost to have it done.

As far as the ebay auction LSD, looks like a 2 way. This video explains ramp angles, etc.

 

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I've been pondering these issues as well.  My build has 486 torque, and I am using a short nose R200 with the T3 parts and Q45 CV axles.  It isn't running yet, so I cannot comment on whether it is up to the task, but I admit to being worried about the R200 surviving hard driving.  There won't be drag racing starts, but I'm not going to baby it either.

 

My initial plan was to just use the R230 and be done with it, but I didn't like the available gear ratios.  Part of my decision was made when I saw that Matt Isbell's LS7 powered Z road racer used the R200 shortnose, at least initially, and is doubtless putting out more power/torque than mine will.  I don't know how it has held up in his car...

 

Meh, too much invested now, so I am going forward with the R200 setup, sink or swim.  But if I was starting over I would do the Ford 8.8.

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The thing that worries me most about any shortnose swap, Nissan or Ford, is the front mount. Any mount that attaches to the front of the diff and then to the strap holes in the chassis is insufficient, IMO. Having "arms" that are attached to the strap holes essentially gives the diff more leverage to rip the chassis apart, and we've had several members tear up the strap hole area of the chassis, which is probably the strongest part of the whole unibody. Needs to be a cradle that holds the entire diff, and attaches to the strap holes in front and the mustache bar bushings in the rear. 

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Posted (edited)

T3 seems to have two different mounts available.  The old "bad" kind and a new one.

 

https://technotoytuning.com/nissan/240z/complete-r200-short-nose-r230-rear-end-conversion-z-car

 

https://technotoytuning.com/nissan/240z/z-power-cradle-short-nose-r200r230-and-ford-88

 

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Edited by NewZed
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Posted (edited)
14 minutes ago, NewZed said:

 

 

Yeah, when I initially ordered the T3 parts, they came with the front mount in the top photo, which it is very easy to see is far too weak for the job at hand.  When they came out with the lower setup, I upgraded to that, which of course is just more money after what was already an expensive "kit".

 

The new one does seem to be a good design though....how they should have designed it all from the start.  It also can fit the Ford 8.8 diff should I need to upgrade to that down the road.

 

I posted above that Matt Isbell's LS7 powered car started with the shortnose R200....just because I saw an underside photo of it at one time.  I just read somewhere else that it now runs a Ford 8.8.  I'm sure he didn't swap them for fun.....

Edited by Ironhead

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Posted (edited)

Not to hijack my own OP (but not totally unrelated), how about the driveshaft? On my old setup, I would routinely destroy the driveshaft @ 300lbs torque on the L28et. If I remember right, it was a 280z unit I would grab from junkyards  for the r200 swapped into my 71’. Eventually just got fed up and had a truck shop install a U-joint assembly that was much heavier but lived forever. I think it was a “spicer” joint? This was at least 15 years ago. 
 

Given my list of potential engines, I know I will need a custom unit. If I keep my r200, it will need the 4-bolt pattern on the rear and adapt the front spline to whatever tranny will work with the swapped engine. 
 

given the SCCA status of the car, I would prefer an aluminum unit since I’m addicted to quick response. 
 

Apologies again for being a little clueless. It’s been at least 10 years since I even looked at my old powertrain setup. any thoughts? 
 

 

Edited by AydinZ71

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@AydinZ71 That Nismo diff looks good. Something with clutches will be far superior to a helical. OSG, KAAZ, or ATS are other good brands to look for.

 

I recently had a custom driveshaft built. You probably want 1310 u-joints, and you'll need a Neapco N2-2-899-1 flange yoke for the long nose R200's. 

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2 hours ago, JMortensen said:

That "cradle" from TTT looks insufficient to me as well. I'd run both if possible while working on a different solution. YMMV.

 

It is just four small bolts under tension pulling on a thin plate of aluminum, isn't it?  And kind of "levery" on the outboard mounting points.  You can almost see the metal fatiguing around those outer bolts.

 

The concept seems to have potential.  It's essentially a variation of the Arisona Z Car setup, that doesn't seem to be available anymore.  Which is essentially a variation of the welded cradle in your big thread.  So close...

 

image.png.499ed4a7dc6236da99c0e4d0e53cd254.png

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13 minutes ago, NewZed said:

 

It is just four small bolts under tension pulling on a thin plate of aluminum, isn't it?  And kind of "levery" on the outboard mounting points.  You can almost see the metal fatiguing around those outer bolts.

 

The concept seems to have potential.  It's essentially a variation of the Arisona Z Car setup, that doesn't seem to be available anymore.  Which is essentially a variation of the welded cradle in your big thread.  So close...

 

image.png.499ed4a7dc6236da99c0e4d0e53cd254.png

 

This is the steel plate cradle, their aluminum option is a billet piece that looks substantially thicker. 

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Posted (edited)

On the edges, but they thinned it out for some reason.  Weight savings?  Still a lot of leverage on those outer mounting points.  Why didn't he CNC it all of one piece?  And look at how little material there is around the outer mounting bolts.  You can easily imagine that whole plate tearing right off of those four outer bolts.  

 

Hard to stop once you get going.  It's just not "substantial" enough.  And, last "pick" - it looks like a solid mount.  So it's going to be noisy.

 

image.png.526215435fa70ea97123549d08510ecf.png

 

Easier to visualize the diff nose lifting with the picture right side up.

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Edited by NewZed

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Looks like it's thinned out to save weight and be easier to install and not be inches thick, interfering with the control arm action. I imagine it has to be several pieces to accommodate chassis flexing over the years and being out of square. The steel plate appears to be 3/16"-1/4", the aluminum is probably close to 1/2". 

 

I guess looking at those photos, I'm not seeing the issue that you see. The diff isn't twisting in a way that it will break the thin side of the slot, and pulling the bolt head through the plate isn't going to happen. They've bushed the diff properly here so it's free to flex more or less independent of the "power cradle". 

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Posted (edited)

Who knows.  The parts have a lot of flash to them, they look nice, but no results posted or shown.  Just words, saying that it's stronger.  A little story about the 10 second Z car that used them would be neat.  A video would be cool.  Why does he sell aluminum and steel but just show the steel parts mounted?  Edit - I guess he shows both.  Just an odd assortment of upside down pictures.  Hard to tell what's going on.  Questions...

 

If the bushings are clamped down with metal contact at the bolt and the nut the noise will transmit through the metal.  Hard to tell.

 

Hopefully somebody will try one and see what happens.  I'm just an internet critic.

 

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Edited by NewZed

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17 hours ago, Ben280 said:

@AydinZ71 That Nismo diff looks good. Something with clutches will be far superior to a helical. OSG, KAAZ, or ATS are other good brands to look for.

 

I recently had a custom driveshaft built. You probably want 1310 u-joints, and you'll need a Neapco N2-2-899-1 flange yoke for the long nose R200's. 


gotcha. So I shouldn’t use my existing home as a core? I was assuming they would be cutting and welding the existing yoke onto the ujoints of my choice. Il take a look at those part numbers thank you! 

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Posted (edited)

For now, since you still have the L, just get a 280Z shaft. It will be the right length, and you can try and match up the bolt pattern to your diff flange. IIRC the 280 diff has different bolt pattern than the Z31 R200. 

That NEAPCO part that Ben referenced is for when you get the big power motor in the car. Then you'll need to swap the transmission, and at that point you'll go to 1310 joints, use that flange and have a new shaft built. I think Ben's transmission uses standard American car stuff, so he probably has Camaro or similar slip yoke, that NEAPCO end on the diff side, and then a custom steel or AL tube in the middle. That's what I did on mine too (steel because it was cheaper and the weight difference was like 2 or 3 lbs), but you're not there yet.

EDIT--Thinking maybe your 240 shaft will bolt right up to the R200? I remember there was one or two years that used 10mm bolts instead of 8mm. I think the rest is the same though???

Edited by JMortensen

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The 1975 280Z propeller shaft and R200 is the one with the odd bolt pattern and bolt sizes.  Avoid 1975.  And the Z31 has its own bolt pattern also, as you recalled.

 

I think that the 240 shaft itself might be of smaller diameter than a 280Z shaft.  But the 240Z shafts have replaceable u-joints so it's easier to do a yoke swap, if you find a yoke with internal clips.  The 280Z shafts take extra machine work to get that done since they have staked u-joints.  I think that the 260Z might also have staked joints.  And, of course, the early 240Z's with the forward mounted diffs have the 1 1/2" shorter propeller shafts.  Lots of ways to get stuck.

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I have this monstrosity that I built as a front diff mount.  It is .25" steel, and simultaneously ties into the suspension pivot mounts, the four strap mounts, and a .18" reinforcing plate welded to the top of the driveshaft tunnel.  I am certain it is strong enough, but it is bulky, heavy, and a bit of a PITA to install.

 

If the "new" TTT setup fails me, this will be waiting in storage as a replacement.....

 

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10 hours ago, AydinZ71 said:


gotcha. So I shouldn’t use my existing home as a core? I was assuming they would be cutting and welding the existing yoke onto the ujoints of my choice. Il take a look at those part numbers thank you! 

 

See what @JMortensen and @NewZed said about non-replaceable u-joints! (THANKS NISSAN!) The Nepaco piece is just what you need if you want a driveshaft made with the stronger 1310 style joints.

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Posted (edited)

I've sold the uprights seperate from the rest of the kit to some guys btw.  They bolt up to 2004 neon lowers and use 2014 or 2015 mustang brakes, and hubs.

 

Just drill them for whatever hubs you choose.

 

I also sell the tabs to convert any strut to neon style...

 

But the complete kit is dirt cheap, and guys have been unable to break them.  165+ mph and no vibration issues or anything either.

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Edited by Invincibleextremes
Added pics

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