NewZed

I wonder why Nissan puts check valves in the MC outlets of their four disc cars, if they're only needed for drum brakes. Maybe not needed, but offer some small benefit? A mystery.

These axle conversations never satisfy. Weird how the endless loop continues, never really adding much. At least this round has led to the knowledge that there are nine CFJ kits out there somewhere, five for one of the S30 bodies (narrrow 240Z or wide 280Z?). Maybe one of those people will drop by and offer some real-world insight. Also, zcardepot has reported some of his manufacturing process in a different thread. Of course, some questions remain unanswered. Apparently he'll be putting together and installing a kit soon though so might have some feedback. Some progress is being made. The company that makes good parts, fills the knowledge void, and can add a feeling of security (real or not) to a purchase with numbers and results will probably win the battle. Many threads out there from people asking questions then moving on to something else when there are no answers. Anybody know what material the stock flanges are made of and their heat-treatment?

Oops. Didn't follow my own advice... My mistake. 39 spline axles? Plus, one's for the R200 and the other the R180.

Now I really feel ignorant. 1976 shows a check valve also. I have check valves. I wonder if instead of removing these check valves, they should just be replaced with a lower force (pressure?) valve. 2 and 10 lbs seem to be the options. Might be a fine detail, but if they've been using them in all models, they would seem to have some benefit. Opinions seem to vary though - https://www.mico.com/sites/default/files/document-pdfs/81001017Residual%20Pressure%20Valve.pdf I feel smarter now. Good luck dreco.

Just noticed that the MC I showed appears to have residual pressure valves, aka "check valves". I need to "upgrade" my brakes so I can learn more stuff.

Found a few things. Interesting. Seems likely for dreco. Carry on. http://www.mbmbrakeboosters.com/index.php?option=com_content&view=category&layout=blog&id=8&Itemid=16 http://www.championtrailers.com/content/remove-residual-valve-instructions.pdf http://www.freeasestudyguides.com/residual-check-valve.html

Miles, how do these residual pressure valves work and what is their purpose? Just trying to learn something. Are they spring-loaded check valves, that release back to the reservoir at some set pressure? Seems like an odd thing, maybe meant to work with certain parts.

Typical MC at rest. 1980 280ZX Tokico brand.

When the rod in the MC is back to its proper starting position it's impossible to hold any pressure in the hydraulic system. The formerly pressurized system is completely open to the atmosphere. Unless the cap on the reservoir is sealed and has all vent holes blocked. It's just the way they're designed. You can see it in the drawings. Unless, apparently, you have one of the special ones described above.

The rod from the pedal to the booster, in the cabin, might be too long. Not allowing fluid back in to reservoir. It's been discussed many times if you want to search around. "Sticking brakes", "brakes won't release", etc. If this was the case, pulling the clevis pin on the brake pedal should release the pads without opening the bleed valves. If it's the booster, then loosening the MC from the booster should do the same. A quick check of the mechanical pieces.

Only posted because the general vagueness around this topic is fascinating. Horsepower numbers, buzz words, lack of specifics. The driveshaft shop at least has some informative discussion on their web site. Hard to tell who's making what and who knows what they're doing.

Beats your guy by 200. http://www.modern-motorsports.com/datsun-240z-280z-complete-cv-axle-conversion.html

One could argue about how warm an engine is after a "few minutes". You can see a possibility for mis-interpretation though.

I would get in to the details. You're looking for something big but it's probably something small. Could just be a vacuum leak at a carb gasket. Spend some time understanding what's really happening. You said it backfires through the carbs when you rev it, but you also said " I did get it to run the other day long enough" implying that it won't even idle. Won't idle and won't rev are two different things. If you're using an E12-80 module use a coil that has specs. close to a ZX. Like ~ 1.0 ohms primary circuit resistance. Be careful with your cam swaps and lash adjustments. The cams don't tolerate certain things and will wipe a cam lobe pretty rapidly. Backfiring through the intake can also be a sign of a wiped exhaust lobe. Make sure that your lobes are still lobes, and not cylinders.

Back at ya. What is your idle ignition timing? What is your mechanical advance curve, approximately? Is your camshaft installed so that lobes open and close the valves at the appropriate times? You're swapping parts, but don't seem to be setting them up to function properly. Timing is more than everything with an engine. Could also just be running lean. That causes intake backfire also.

1. The electrical circuit that controls the lights. 2. Timing: ignition and cam.

JMortensen has written in the past about removing the springs and running the suspension through its travel range to make sure there's no binding. Nobody seems to do it when they have these problems, but it would probably be informative and save a bunch of head-scratching in the long run.

Notice how tall/deep the zcardepot flange is. Might not work with someone else's axle.

Higher height from a lowering kit is an odd situation. Maybe they're on sale for a reason. http://www.thezstore.com/page/TZS/PROD/23-4042 Bumper weight is gone but probably a small effect..

I did miss the title pieces. Best to list things out, for me anyway. You didn't mention the bushings. With factory rubber bushings, the caps need to be torqued with the car down, and rolled to unbind the tire/ground contact, and at ride height. If you torque them with the suspension hanging the rubber will hold the car up.

The lift under the crossmember hasn't been released. It hasn't been rolled to unbind the suspension after lifting. That guy in the picture is very strong and is pulling up on something. You have low profile tires, creating a bigger gap. You installed too-tall springs. There's a few clues. You haven't really given any info about the parts. Springs, isolators, perches...every car has those.

Never mind. You have the signs of a difficult customer.

You're dumbing down a lot of detailed information. "930" is a CV design, with a variety of materials used and manufacturers involved. They're not all the same. "Q45" is a car not a diff. The Q45 came with the short-nose R200, not the R230. The R230 came on twin-turbo Z's and SUV's. "Chromoly" is an over-used word that actually means very little. You can have a "chromoly" axle that will twist like a pretzel if it hasn't had the proper heat treatment. Seems like you haven't really absorbed much of what people have been offering. Look through the nicoclub FSM's to learn about the diff options. If you're not careful you'll buy an R230 kit, for a Q45 short-nose diff, with a 3.13 gear ratio. Not good.

Body Electrical has a clear schematic. I'd post a page number but you didn't post a year.

Early 280Z, late 280Z, or 280ZX? They all use a different EFI relay. If you studied the wiring diagram you'd probably realize that you can work around it. Half of the early Z relay is the fuel pump relay.