JMortensen

That is not a bias problem, your rear brakes aren't doing anything. That's a blocked or pinched brake line or some other failure in the system, or that full pedal just squirted a whole bunch of brake fluid inside the drums. Check the soft brake lines and wheel cylinders for leaks and bleed them again. If barely any fluid comes out then its a line blockage. Happens sometimes when cars are stored long term. I've managed on one or two occasions to blow them out by quickly stomping on the brake pedal, but usually that just lets a bunch of crap loose in the lines and it then takes out the rear wheel cylinders...

Yes. It's also the one that Precision Gear said wasn't available anymore.

Your neighbor is senile. You don't want anything but the edge of the fire ring exposed to the combustion process. If the gasket is hanging out past the cylinders it will burn up and fail very quickly.

Again, thanks for posting your findings, this is really valuable info. I'll merge this thread with the motion ratio thread. If you could then keep going on that one thread that would be great. The B/W/S/C forum is getting plugged up with too many stickies, and all of this info is certainly sticky worthy!

My understanding on that one is that the output splines in the LSD are different than what the Z's came with. If you search you should find the right answer, but I think it's a no-go unless you came up with a CV shaft that used the Subaru inner CV and some outer that could be adapted to the stub axle.

I asked him that question in another thread. He said a couple lbs.

Dan, what's your next move? If it's going to be another really important measure or weigh in of some part of the suspension, can you do it here? I think I'm going to merge this thread with the motion ratio thread eventually and give it a title like motion ratio / unsprung weight / etc. These are the types of questions that one has a very hard time finding answers to and they become increasingly necessary when you're ready to get really serious. Thanks for sharing this really valuable info with the rest of us.

That's a pretty well cleaned up chamber Tim. A big improvement over stock I'd say.

They were coil bound the whole way down? They don't look like it in the photos on the previous page. Plus that would mean that you didn't have any suspension at all. If the first 4 coils were bound or close to it, then that is a normal progressive spring, as previously explained by John Coffey. The front Tokico springs are supposed to be that way. What they shouldn't do is bind ALL of the coils before the stut top hits the bump stop.

That makes a lot of sense, silver280zx. Doesn't look like there is much travel in those Tokico springs, and if they did bind it would be much harsher than hitting rubber or poly bumpstops.

I think it's a bumper, meant to stop the side with the larger bushing from squishing really far. Probably serves no purpose if you've gone to poly rack bushings. I used a pair to mount my modified rack to my crossmember.

The place where the head is .035" - .045" is the quench area. That part is important in reducing detonation. The "super high heat" is the cause of detonation. Sand the sharp corner and it won't get as hot, less heat, less detonation. Pictures would help here. In general I would agree that for an NA engine utilize the quench as much as possible. This is why the E31 is not as good as the P or MN heads. Dig around and see if you can find pictures of John Coffey's Sunbelt head. It is basically as you describe. The chambers and pistons are coated (not sure about the valves). I can't remember what Tim said he did to the chambers, but I'm pretty sure at those power levels they aren't stock. Comparing his head to an off the shelf head is not the best way to get a good result. I think a major difference is as I said before, turbocharging. This is a pure SWAG, but there is something about the turbo that seems to make the quench less effective. I'm guessing that the fill of the chamber is so much more dense that the quench doesn't have as much effect.

Put a big screwdriver in the U joint to hold the driveshaft in place. Use a LONG 12mm wrench on the nut if you have a 240, I think its a 14mm wrench if its a 280. Unfortunately, especially with a rear sway bar that attaches to the frame in front of the diff, the driveshaft bolts are just a big PITA. I'm changing your title, as I had no idea what it was about before opening it. Could have been driveshaft removal, driveshaft vibration, driveshaft shortening, custom driveshaft, etc...

The alfa did indeed have inboard brakes. They were a pain in the ass to work on as I recall, but it's been probably 15 years...

I too ordered from Juan and got my parts reasonably quickly, although the transaction was not what I would call perfect. He was developing his 12.2" rear disk brake kit at the time and after my parts were delivered he posted here saying that they "might not" work without wheel spacers. Soon after that he dropped off the Hybrid Z radar for quite a while. I still haven't bolted them on, but I have no problem using a wheel spacer if I have to. This could have been a very big issue for someone else though. On the upside, the parts appear to be of good quality, plus I was able to piece together an entire braking system for many hundreds of dollars less than the Arizona Z Car or Modern Motorsports alternatives. Juan only recently came back to our forum and does not seem to be a "regular". The issue we sometimes have with parts suppliers is that Z cars are such a small aftermarket that big time parts suppliers don't want to bother. The "little guy" shops that do work with us don't have a lot of capital to get started and may not be able to absorb financial losses well. I have no idea what happened with Glenn's order, and I hope his situation gets taken care of quickly, but I get the feeling that if a couple grand worth of parts were lost in transit that it might be difficult for Juan to simply write a check to replace those parts. Glenn, please let us know how it gets resolved. Hopefully the parts were sent with some sort of insurance and if nothing else a refund might be had through USPS.

The biscuit style plate that John sells has several adjustments on it, which move the caster and camber settings together, but it does not have an infinite adjustment. For that reason I don't think you'd want to use it to try and move the strut shaft back. I suppose it might work if you figured out what adjustment you wanted first, and then moved the strut back to line up with that spot. Seems much easier to tilt the strut than to move it back and maintain the perpendicular angle. To tilt you just need a control arm that allows for the tilt without binding, like this theoretical one: http://forums.hybridz.org/showthread.php?t=129154

This sounds too good to be true. Softer, lower, yet doesn't bottom out as much. I get that you're happy with your setup which is good, but this doesn't make sense unless you also sectioned the struts when you installed the new suspension.

Interesting diagnosis. I would think that for the diff to be causing the car to go one way under accel and another under decel that it would have to be locking one wheel or the other, because if it locked both it wouldn't cause a move to either side in particular. I don't really see how that can happen in a clutch LSD. I have driven a broken 2 pinion Nismo LSD and had it locking and unlocking as I drove. The feeling was like the rear was shifting around side to side under acceleration. Other than that there were really no noticeable symptoms. It'll be interesting to see if the OS Giken unit fixes the problem...

This subject has been beaten to death. You're taking a slightly new track on it, but if it goes down the same old road, I'll close it out. Now to approach the issues you bring up: Your first sentence says modern engines "fight squish". They actually use it to fight detonation. Not sure if that was a typo or what. Yes, the sharp lip around the quench pad is prone to detonation. Sand the sharp lip to make it a bit duller, and then it is no longer as detonation prone. People do the same to the valve heads and the piston as well, and it does make a difference. Look at the best 2 valve high performance engines out there like the LS engines or some of the CAD designed Harley engines, and none of them (that I've seen) have spherical combustion chambers. I think the reason why is because you can't have a chamber that large (assuming 2 valves) and then dish the piston to match and still maintain a reasonable compression ratio. Take a look at pics of high compression L series race heads and they usually have the closed chamber like the P heads or the MN head, and then the top of the piston is machined to fit up inside that tiny remaining space to get even more compression. A sphere just won't work on our application, and I think it would be hard to achieve on any application where the valves were large enough for it to be a "performance engine". I'm also not convinced that the sphere would be the "perfect" shape. Seen any newer diesel pistons? They basically use a flat head and put the chamber in the piston, and they've been coming up with some WEIRD shapes to take full advantage of the combustion. I watched a show on the BMW diesel factory the other night and they were showing the piston shape, seen similar shapes in magazines and such. While diesel isn't directly analogous to gas, I think the idea of capturing and using the explosion of the fuel to the drive the piston is sufficiently similar that we might draw the conclusion that spherical is not perfect. I'm open to other ideas here, I just think it would have been done by now if it was. I agree with you on the L28ET part, seems like a flat top would be in a much better position to take advantage of the chamber shape. If you still needed to reduce compression it would be better to use the "1/2 dish" pistons like the V8's do. Essentially its a piston with a dish in a shape that corresponds to the chamber shape. Again, sanding the corners down is important, and when the pistons come out of the box they're sharp right at that corner. Strangely though you will occasionally see some very high hp turbo cars that cut out the quench pads (RB's in particular I've seen doing this). I don't know the purpose, but I would guess that at some point lessening the compression ratio by opening up the chamber has more of an effect in reducing detonation than using the quench to its full effect.

They don't allow rotation of the spindle pin fore and aft, which is what you would need to keep the top aligned. I did some messing around with this when I built my control arms. I shimmed the struts forward and back and compressed the suspension with no springs, and I was able to see the strut shaft moving around in the camber plate hole. More info here: http://forums.hybridz.org/showthread.php?t=106457&page=9 post #168

That's actually a pretty bad idea Dragonfly. Because the control arm won't line up with the strut top and the strut itself can't pivot, you'll be putting some major stress on the strut itself and the control arm. Whichever is weaker will flex as the suspension moves, but those control arms you have are pretty beefy, so you're undoubtedly putting some good strain on the strut itself. If you could move the strut top back to be inline vertically with the strut assy, then you'd be OK.

I wonder what sound it makes when the inside of the rim hits the edge of the fender...

Nissan dealers have a lot of that stuff. So does http://www.motorsportauto.com. Dealer parts are better quality but more expensive.

Maybe I'm reading the table that Brad linked to wrong, but the cams specs do look different to me. Not that it really matters, they're just a hair different and both are way too small. Slightly "wilder" implies that the stock cam has some degree of "wild" which it really does not. That cam you have, even if it is .433 lift, is tiny in my opinion. Regrinds are cheap, I think Delta charges $65. If you want a bigger cam get something that is actually worth the bother of installing. Before you do that though, read up on the stock EFI and its interaction with larger than stock cams. Pretty soon we'll have you going for an aftermarket programmable ECU and a "real" cam...

Pete, that would make sense if you had a Dana differential, but on the Z the shims go outside the bearings on the carrier. They would only need to be pulled off once to switch them from the old diff to the new diff. What we're arguing over really doesn't matter. There is no harm in using new bearings (obviously). If someone has access to the $400 special tool, then they can swap their old carrier bearings onto a new LSD and save $40.