jmortensen

Jesus freakin Christ! Guess I'm not reading this thread really well!!! Sorry guys... If you installed a ZX master, then the pin needs adjusting as the others have said. If you installed a new Z master, then you'll need a bigger diameter master to fix.

You're comparing apples to oranges. When driving my friend's Z with the 4x4 calipers and stock master the pedal is mushy and the travel is longer, but this is because she has a smaller diameter master. That would fit just perfectly with how a smaller diameter master should feel compared to a larger one. Smaller = more pedal travel and less pedal effort. Larger = firmer pedal and more effort required. A side note about this adjustment too. When this adjustment is made there MUST be free play in between the pin in the booster and the back of the master. I'm sure there is a spec in the FSM, but don't cut it short thinking you'll improve the braking feel. Without free play here you can easily end up with a situation where the brakes come on stronger and stronger until you're stuck by the side of the road with smoke coming out of the wheels. If the pin doesn't retract ALL THE WAY then it will close off the port to the reservoir, meaning that the pressure in the system can't go anywhere. The longer you drive, the hotter the brakes get, the more the fluid expands, the more the brakes are applied, the hotter the brakes get, the more the fluid expands, and so on. Seen that one a few times on brake upgrades, and I've personally made that mistake on a clutch. Clutch just slipped worse and worse as the day went on... EDIT--reread the post and updated to fix

The problem is that the 4 piston calipers have a much greater volume of fluid than the stockers. So when you put the 4 pots on you need more pedal travel for the same amount of piston travel at the caliper. Solution is to use the ZX master cylinder, or like you said switch back to stock calipers. I've never run that setup, but I'd wonder about the ability to get the bias right. It's tough to do with ZX rear disk setups, so I'd imagine the fronts would be way overpowered with stock drums too.

It will work, but as Stephen says, where are you going to mount the module? The HEI works as well, so does a Chrysler module. If you're going other than stock, I'd go American, so that if you have a module go out you can go get one at any local auto parts store for $20. As to the wiring, you'll have to figure out that part yourself or maybe someone else can help out. Electricity and I have a longstanding feud. I can tell you that I know it will work, and I've seen cars running the GM and Chrysler modules in person.

Don't clean all the gear lube out of it. Just drain it and put new gear oil in like you would when you change the fluid, and clean/paint the exterior.

50/50 is not "ideal" for anything except car magazine articles and advertising. If you're going to be racing get the weight back on the rear. I think the RB25 is heavier than the L series. The SR20DET mounted as far back as possible is a good idea.

No, I'm not nearly that talented on a computer. It is cool though.

Tabrinn, this is a running disagreement between Carl and me. Running 225/50/15 tires with a 81-83 trans and it's matching 3.90 diff, the rpms should be 3070 at 75 mph. Running a 4.11 the rpms jump to a whopping 3235. To me that is more than acceptable. If you want to play around with tire sizes and diff ratios and see what you find, here's a calculator: http://www.geocities.com/z_design_studio/

1. Don't think so, never heard anyone complain about warped chassis after having their car on the rotisserie. I think there is more stress on the chassis sitting on its wheels with the drivetrain in than there will be on a gutted shell hanging on the rotisserie. When you start welding on the chassis you'll have a lot more likelihood of warping sheetmetal and possibly affecting things. If you're just fixing floor rust and stuff like that I'd say no. 2. No. I don't have a bar connecting the two ends. My garage floor is not totally flat so one of my stands wants to back off the car. After fighting that for a while I welded a piece of tube on the backside so that the mount that bolts to the car can't pull out of the mast. I made my rotisserie from 3 engine stands. If you do two engine stands you won't be able to spin the car all the way upside down, as the roof will hit the ground. I bought a third and cut the main mast up and spliced it in to make the masts about 1' taller than they originally were. You also need to make the masts straight instead of having them lean back. 3. I've got mine attached to the bumper locations in the back and the bumper locations and horn mounts in the front. Working fine that way for a couple years. Some pics/info here: http://forums.hybridz.org/showthread.php?t=104151&page=2 http://forums.hybridz.org/showthread.php?t=105319 http://forums.hybridz.org/showthread.php?t=121912 The one thing I would do differently is make the masts a bit taller. As it is the fenders just barely clear the legs of the engine stands. Tip for getting the car on the engine stand: use a cherry picker on each end of the car with a load leveler. The first time I put my car on the spit I jacked up the car, then put it on jackstands, put wood on top of the jack, jacked it up further, wood under the jackstands, etc until it was high enough to plug into the rotisserie. When I got to my new house I said F it and went and bought a second cherry picker and load leveler. MUCH SAFER AND LESS STRESSFUL.

Agreed. The NA 280ZX 80-83 transmissions had much closer ratios, and are a better choice. Of course to really make use of that close gearing, a new differential is in order. 3.90 gears are what the ZX's came with, 4.11's work well too. The Subaru diff has a different spline count at the side shafts, so Z halfshafts don't work. At least one guy has modded the Subaru CV shafts to work, but it's not as straightforward as getting a Nissan R180 from a 200SX for example. Info here: http://forums.hybridz.org/showthread.php?p=721400

One more option: cut the spring perch off and weld it back on higher. Not hard to do...

Can't wait to see the race on Speed. DVR is already set to pick up all SCCA races...

It's Jon, not Jim, but I get that a lot. I think the bias isn't really a problem until you're trying to get the very most out of your braking, so your average street driver may very well never notice the issue. If you get really competitive with the autoxing then it might be an issue.

Julio, your brake system already has a proportioning valve in it. You could gut the stock valve and add an adjustable valve, but what happens if even when you adjust it all the way towards the rear you STILL don't get enough out of the rear brakes? That's what happened to me with the 4x4 calipers and early ZX rear disk. The only solution I know if is another brake setup or dual master cylinders.

One thing to look out for is brake balance. Things like Toy 4x4 front calipers don't mate up well with drums in back, or a small disk conversion either. As for your available options, some of them are: 1. 79-81 ZX rear calipers and rotors 2. 82-83 ZX rear calipers and rotors with Maxima brackets 3. Modern Motorsports 240SX rear calipers with 300ZX rotors 4. Arizona Z Car Wilwood setup 12.2" with 4 piston calipers and no ebrake provision 5. Modern Motorsports extreme 13" brake package with ebrake In truth there are a lot more but I'd say those are probably the most common ones. If you're using stock front rotors and calipers and don't intend to change the fronts, I'd go for one of the first three. If you go to big 4 pot calipers in the front, I think the first three are going to be too small, and you'll end up struggling to get the bias adjusted correctly.

Can anyone better at math and physics than me work backwards off of the wind tunnel data and figure out what the downforce would be at lower speeds? I'm sure that it is possible...

I think opening the hatch even 1/4" is going to throw those numbers off quite a bit. For reference: http://forums.hybridz.org/showthread.php?t=121877 Granted these tests were done at 80 and extrapolated up to 100 mph, but a 5.25" rear spoiler generated ~105 lbs downforce at 100 mph. (50 lbs downforce and removed 55 lbs lift). Unfortunately you have to look at aerodynamics as a package, and that car also had a chin spoiler so that will affect the total aero balance as well as the front or rear downforce numbers taken individually.

If that works then good job.

Since logic is out the window, why not get some of those Kinoki foot pads and park your car on them? They should detoxify the springs causing the front end to lower slightly.

First, did you roll the car around? If you just set the car down the suspension is pinched under the car. Rolling it around allows the control arms to move and it will sit differently after doing so. Second, did you install the front springs in the back and vice versa? Long springs should go in the rear. Third, there is absolutely positively no way that flipping the springs is going to make the ride height different. Think about it. The spring is getting the same amount of pressure at both ends, regardless of which way you have it installed. It doesn't matter if it is right side up or upside down, that one corner of the car still weighs about 600 lbs.

Is there a way to wire them so that they don't pull timing out? That is the issue with them...

The ZX distributors won't "go bad" from sitting in my experience. There are two common problems with them in my experience. 1. The vacuum advance goes bad. This is true of every ZX distributor I've seen, except one. So you can plan on fixing that if you want the vacuum advance to work. 2. Much less common is the module going bad. They do go bad from time to time and they are relatively expensive to get a new Nissan unit. Your options are to get a new one or to wire the distributor to use a different module, like the GM HEI. I have the general impression that the HEI tends to go out with more frequency, but you can get a new one at any corner auto parts store for $20. On the trans I think the BW trans is the wrong way to go, especially if you don't have a turbo. It MAY be marginally stronger, depending on who you ask, but it has very wide gear ratios. The 80-83 NA ZX 5 speeds have much closer ratios, which is a lot better for performance driving use. Of course, you really need the diff to take advantage here, because if you get the tall 1st gear and have a tall rear end, you're going to end up slow off the line. I like a 3.90 with the later 5 speed (that's what the ZX's came with) or a 4.11. I had a 3.70 with this combo in my car for years, it did fine, but it was noticeably tall to me and gave a theoretical top speed of 170+ mph, which wasn't going to happen in my car unless it was dropped out of an airplane. Distributor rebuild info: http://www.jrdemers.com/280ZX/distributor/distributor.html

NICE WORK!!! I had been figuring on having to have the spoiler mounted way up on the hatch to prevent it from extending past the body of the car!

Any comments about your spoiler Tom?

I want to know if Rick got his stumble figured out and what kind of difference Tom's spoiler made. Good job guys, congrats JT!