JMortensen

Any time! Glad to hear it worked out.

Pinion nut torque shouldn't change the torque to spin the pinion. The resistance comes from the distance between the two tapered roller bearings. If you have significantly more resistance than that, the most likely cause is the pinion seal dragging on the pinion flange. Did you grease it? Did you seat the ball bearing and the seal all the way?

Don't open the higher bleeder. Just let it come out the master, as that bleeds the master as well.

You don't need check valves. I was having a hell of a time bleeding my brand new system with new calipers, soft and hard lines, and masters. Tried the usual method, a vacuum bleeder, nothing was working. Ended up using a 50cc food syringe that we fed my daughter with when she was a baby and had throat surgery. Just stuck a little section of tubing on the end, and hooked it up to the cracked bleeders and forced brake fluid through the lines. Worked great. Did my clutch the same way after initial bleeding didn't get the air out of it. Seems like the way to go, and I guess motorcycles do this pretty commonly. This one looks like it would work. http://www.ebay.com/itm/50ml-Plastic-Disposable-Syringe-For-Measuring-Hydroponics-Nutrient-60ml-50cc-NEW-/191938379599

You can tune the OSG diff too. I am 95% sure they offer different cross pins and pressure rings so you can vary the lockup. Just reduce lockup on decel and you should get what you want.

We use threads in bending on Z's all the time. Look at just about any adjustable control arm, whether it be Arizona Z Car, Modern Motorsports, etc, they all have a threaded rod end that gets loaded in bending. Many of them use that kind of adjuster as well. Mike Kelly's old arms used that kind of turnbuckle. While it isn't ideal, I don't agree that it's a crap design or that it is destined to fail. I've got them all over my own suspension too. I do think there is something to be said for not having a lot of threads exposed, which is why I really didn't like Ross's rear arms for example, but he was using 7/8" threads IIRC, so I think his defense was despite the long section of threads in bending, the material was thick enough to take it. One difference in this case is the poly bushings. The poly bushings cause a heck of a lot of stiction, and that combined with the threads in bending might be more problematic.

[pedant]Where's the "true" wing?[/pedant]

Drive it until it happens, then crack the brake bleeders. If that solves the brake lockup problem, then it has to have something to do with residual pressure in the system. I hadn't heard of Dan's issue with overfilling, but I've experienced the other one firsthand with a clutch system, but same problem. Thought it was a good idea to take the slack out of the pedal to master adjustment. The more I drove, the more the clutch fluid heated up, the more it slipped.

Narrower front tire will increase understeer. Other than that will be fine.

We have a thread with motion ratios and all that calculated out: http://forums.hybridz.org/topic/63492-suspension-tech-motion-ratio-unsprung-weight/ The front and rear motion ratios are pretty close.

Looks like it is not back in production. Part number LOM59 comes up no match on Amazon.

Wha wha wha??? The Power Brute is back on the market?!? It was unavailable forever. Same manufacturer that made the Z31 LSD, but has more aggressive ramps and more clutches. That's a SMOKING deal!!!

If that all sounds like too much hassle, might be easier just to get another used diff.

Factory Service Manual tells you how to get it apart. Basically pull the carrier again, remove pinion nut, press the pinion shaft out, then pop the pinion seal and there is a long spacer and the outer bearing. I'm thinking that outer bearing is the issue. As to replacing the bearing, check and see if it's available from Nissan. I seem to recall it's not an off the shelf part. I think the tapered bearings are, but the ball bearing is a weird one. That's old memory talking, so you'll have to double check me. You can download the FSM here: http://www.xenonzcar.com/z31/fsm.html

Spider gears only move when you turn.

The pinion bearing preload is set with a solid spacer, so the torque is not really relevant unless the pinion nut comes loose. You should be fine. Seems to be that Z31 diffs tend to lose the front pinion bearing, the ball bearing right inside the pinion seal. If you have one apart to the point where the carrier is out, spinning the pinion will feel gritty. Seen it several times, makes an obnoxious whine. Here are some tips on diagnosing diff noises from my former employer: https://www.ringpinion.com/TechnicalHelp/contentframe.aspx?filepath=%7e%2fcontent%2fhowto%2fgeneralinfo%2f%2fdiagnosing_noise_(part_1).inc https://www.ringpinion.com/TechnicalHelp/contentframe.aspx?filepath=%7e%2fcontent%2fhowto%2fgeneralinfo%2f%2fdiagnosing_noise_(part_2).inc

I agree, Gary Savage is your guy and he should be able to hook you up so you can rebuild the CLSD, which is superior to the helical IMO. I still think the OBX is fundamentally workable, it's just those stupid spring washers that screw things up. Replace them with a solid spacer and it should be OK.

http://forums.hybridz.org/topic/105657-300-zx-turbo-cv-shaft-disassembly-and-reassembly/

It gets you about 1/8" more clearance, which is not enough. If you need more room because you're using Modern Motorsport adapters with Z31 CVs you should buy the halfshafts that make it fit, or longer control arms. http://www.modern-motorsports.com/z31-half-shafts.html I'm positive I posted about R&Ring the CV's let me see if I can find it.

Cam/headwork, and the FI to go with it. You could hit that goal with just the cam and the MS. My question is why bother? If you're already thinking 5.3 swap, a mild bump from all that work isn't likely to cut it for you. Save your time and money and do the swap is my advice. I'm speaking as a guy who built a 2.8 with a little cam and SUs. Went bigger on the cam, then went triples. Then rebuilt it for higher compression, did a bunch of headwork, then realized I had wasted a whole lot of time and money and did a 5.3 swap.

Something's obviously not right... sounds like the people to ask at this point are OSG.

Weren't you running an OBX LSD? The reason for the CVs hitting the diff housing is likely wasted washers in there.

Did one for my 44s back in the day. Took A LONG time to port the entire length of the manifold, and I agree, the casting is really crappy quality out of the box.

I believe the final jetting was 185/185. I thought they should have gone up one more step on the pilots, but time was limited. I have a feeling you'll be working with the emulsion tubes for the chassis dyno to get the bottom end leaned out a bit. Want to say John's motor made 287whp. As he used to say though, every dyno is different and you really can't compare numbers from one to the next. I know he had another dyno that said 270 or right around there for the same motor. He also had FI and Motec IIRC, which adds a lot more tunability (can adjust each cylinder individually, etc). What impressed me most about the day was 27 hp increase with the swap to the bigger carbs, and really no bottom end loss at all. That's a 10% gain! HUGE! That and we all thought the 40mm chokes would get Mark over 300, but just moved the curve up 500 rpm. I remember that comparison dyno graph differently. We did a number of pulls, I wonder if Arnie pulled out a different one. The one I recall had a fairly smooth round top on the 36mm pull, and then the 40mm pull topped out right at 7250, and there really wasn't a dip on the far side, and you were giving up more power under the curve. Might just be remembering wrong. Anyway, it was a bit nerve wracking for me. I was way more nervous than Mark. LOL. He was pretty zen about the whole thing. Good to meet Joe too!

The problem with the shortnose R200 or R230 is that very few people make a cradle to mount them. If you mount the front of your diff to the diff strap bolts with a long mount, you're going to pull those bolts right out of the chassis, as some people have now done. I'd rather see a cradle that mounts to the front and rear diff mount bolts (could incorporate the control arm pivots) and then bolt the front and rear of the diff to that then have these setups where the mustache bar is modified and the front mount is modded but they aren't connected. My opinion is that is insufficient.