JMortensen

Or a Wilwood kit for $789? There is nothing particularly great about the Toyota calipers. If you're going to go to the hassle, you might as well drop 5 lbs per corner and get a bigger brake pad with an aluminum caliper.

Very common on Porsche rotors. Take John's advice and you'll be OK.

Buttonwillow is tough on brakes, especially if you're going clockwise and using the hairpin before the esses. I punched a hole through the back of a brake pad with the piston at the end of the bus stop: I think pads are the most common problem and the right pad can make a huge difference. Brake fade where you step on the brakes and the pedal feels fine but the car doesn't slow down any more is probably the most common problem. Then you have pad "chunking" where large parts of the friction material come off, basically the pad overheats and starts to break apart. After that it's boiling the fluid, when it boils it becomes compressible, so the pedal suddenly goes to the floor (done that several times at Buttonwillow too). To fix this you need more heat capacity (bigger thicker heavier rotors) or more ability to shed heat (ducts). Rotor issues are pretty uncommon, except for cracking between the holes of cross drilled rotors. Don't worry if you see cracks, they don't really matter until the bridge the span between one hole and another, then it's time to replace them. I think a lot of brake issues can be solved with the right pads. Hopefully someone more in the know will come up with some recommendations for you. I ran R4's and R4S's and that was it so my experience is pretty limited. I did like the R4 pads, the R4S wasn't suited to track use as can be seen in the photo.

Safe way is to put the prop valve in first, and then if you can't get enough rear brakes take it out or play with pads. I'd be inclined to leave it in and play with pads.

Bad wording on my part. I was trying to say that it is similar in that the other side of the diaphragm is affected by the pressure in the cabin, not say that they are both connected to the pitot tube.

It's bearing noise. Could be input, I think it's usually countershaft. I've been told it can be related to the mainshaft nut loosening up. I have a friend who rebuilt her trans, and within a week it was doing it just as badly as before. She had it rebuilt again, same thing. I think that transmission has been in the car now for 8 or 9 years, still makes the noise, no other problems. If it bugs you you can fix the bearings, the question is how long will it be fixed for?

I was interested in the airspeed thing and apparently it works the same way as the altimeter, with a diaphragm comparing the pressure in the pitot tube to the pressure in the cabin, so this would again explain why the gauge would read high if there were lower pressure in the cabin than there would be without some loss of pressure due to Bernoulli's Principle. I get what you're saying about YOUR plane, but I still think the idea is pretty straightforward and all that needs to be changed to make the statement accurate is to say that the altitude and airspeed may VARY from reality based on the difference between cockpit pressure and the still air pressure at your altitude where you are flying, or they could say "most unpressurized cabins read high" or something like that. Link describing how the air speed gauge works: http://www.aerospaceweb.org/question/instruments/q0251.shtml

Heavier is bad. I can't say I've ever heard someone say "those 240 hubs are just too weak", but you will occasionally hear of someone with a spun race in a hub. If you have a bearing issue, then swap them out. Otherwise I'd keep the 240 parts.

The T is the prop valve. It has a bolt in it. Take that out and you'll see that it is a needle/spring setup. Cut it off, reinstall the bolt. You've now gutted your prop valve. Or just put the adjustable one in right there and use a universal T on the other end, you'll need to be able to find the right fittings or re-flare the tubing to work with SAE fittings that fit the T you buy.

The air pressure we're comparing is not the air pressure inside the cabin and the low pressure air traveling over the surface of the plane. The comparison is the air pressure at a given altitude (outside air pressure) vs the air pressure in the cabin. The cabin pressure changes because of the air flow over the cabin. The question doesn't mention Bernoulli by name, and says "outside air pressure". It seems obvious that this is referring to air pressure at the altitude the plane happens to be at, not the air pressure in immediate vicinity of the aircraft. Here is the original quote again: Poor wording perhaps, but it seems pretty clear to me what they are saying and what the reason is, and why.

I suppose you're right, I just assumed that there weren't any other obvious leaks as it sounds like he's been over the system a bunch of times.

I still don't see the contradiction here. I'm not a pilot, but it seems obvious to me that you would have lower cabin pressure in a non-pressurized cabin because of the Bernoulli effect. It's the same way that Bernoulli causes the gas to be sucked out of a carburetor. The airflow through the venturi creates vacuum in the ports and sucks the gas out, in the same way that the high speed airflow over the cockpit causes air to get sucked out of whatever opening there is in the cabin, again assuming that you don't have a vent facing forward for a ram air effect. I think I just figured it out. The altimeter readings are not fed through the pitot tube. That means that using Bernoulli to suck air out of the cabin will create a false high altitude reading. This description of a sensitive altimeter makes no mention of the pitot tube but does say that the altimeter's reading is based on the air pressure vs spring pressure inside the gauge. http://www.auf.asn.au/groundschool/umodule3.html

That is the classic test for a master brake cylinder. Yours failed. You might be losing fluid into the master, you might also be transferring it from the front reservoir to the rear. Regardless, your master needs to be changed.

I think I am one of the people who talks a lot about bias issues, but that isn't the setup I was running. I ran Toy 4x4 solid rotors in front and early 280ZX (10.5" rotors) in back. With that setup I ran without a proportioning valve at all and still the car wouldn't lock the rears while driving through a puddle and slamming on the brake pedal at a driving school. It's possible that changing pads would have helped, but I didn't know enough at the time to really get into running different pads front and rear. What did work on that setup was switching back to Z 2 piston front calipers. As to your comment about vented rear brakes, I think you're mostly right, but maybe a bit overstated. I know the BMW's need more rear brake than they have. I had a friend who was a BMW mechanic and he would tell me about people going out for track days and ruining the rear brakes, especially the cars that didn't have an actual LSD and just relied on applying the brake on the inside rear to keep the tires from spinning. Again to use my own experience, running those same 280ZX rear disks at an autox, with 3 drivers and 4 runs each I got the rear brakes so hot that I couldn't touch the wheels. I've also had cheap pads chunk on the rears at the track as well. I think it is possible to push a small solid rear rotor too far, especially when the bias is correct. Most of your aftermarket "big brake" kits have vented rear rotors, and I don't see that as a particularly bad thing. It may be a bit overkill for most people, but it reduces the likelihood of pads disintegrating or fluid boiling. I do agree wholeheartedly that the front is the one that is likely to have problems, the harder you can brake in terms of g forces, the more the front brakes do relative to the rear, so the faster the car gets the more front brakes you need.

http://forums.hybridz.org/showpost.php?p=1037924&postcount=91

That does seem like a mismatch. Maybe you should buy the fronts from them and the rear 300ZX kit from Modern Motorsports. They both use 300ZX front and rear rotors...

That car is a nightmare. Run away, unless you have a welder and tons of spare time and love nothing more than patching panels and doing body work.

I would clean up the spindles with some scotch brite, then use the hub itself to put pressure on the bearing evenly and see if that works. Just put both bearings in the hub and use the castle nut to draw it down on the spindle. I'm not sure what the problem is, but it should work without a problem, according to the part numbers and all that. If it doesn't go all the way on it should be pretty easy to pry off the spindle.

Using the Timken tool, the inner bearing is a Set 6. The actual part numbers are LM67048 bearing and LM67010 race. I can tell you I just put a LM67048 on my 240 strut the other day and it fit fine, and the wheel bearings are all the same from the 240 through the 300ZX. I think you just had it cocked or something. Should fit.

That's a lot of brake for a 2400 lb car. Love the idea of floating slip on rotors.

I think they mean STATIONARY outside air pressure is higher than the pressure in the cabin, because the cabin is ostensibly having some of its pressure sucked out by the low pressure MOVING air around the fuselage. So if the air pressure is 11 ft/lbs at altitude and because of some air pressure being lost the inside the cabin is 10.5 ft/lbs, then your altimeter reads high etc.

Set 6 maybe? Just guessing... You can look up bearing numbers on http://www.timken.com. Here's the actual page where you can do the lookup: http://www.timken.com/en-us/Knowledge/ForMaintenanceProfessionals/Pages/AutomotiveAftermarketPartCatalog.aspx

What you have there looks good to me and it sounds like you got a great deal. I don't think the bends are a problem. Unless you have a mandrel bender there is going to be some stretching of the tube. I'd try to get the bottom as close to the wheel well with the top as close to the map bar as you can. I think you've already seen that it's a compromise one way or the other. Then you get to figure out how you want to mount the bottom of the hoop to the car and decide where you're going to cut the tube. That was the nerve wracking part for me. Since mine was sprung against the rockers I notched the tube and attached it right to the rockers. What I would do in retrospect is build out the rockers in that area so that the tube sits right on top of the rocker which is maybe 2" wide or something like that. It's tough to get around the backside of the hoop, I cut holes in the fenders, both in the wells and in the dog legs to get access. Id suggest you tie into as many surfaces as you can, the walls of the car, the rockers, wheel wells, the floor, etc.

The stock rotors are 11", and so are the vented that people use with the Toyota calipers. You could do a caliper bracket like the one that comes with the Arizona Z Car brakes and then use the Toy calipers and a 12.2 x .81 rotor, but those calipers are really heavy, so if you're going to that trouble why not get some Wilwoods or similar?

Maybe. Not sure. All I know is that the plastic tube pinched in mine and I determined that it didn't read accurately, then after I went to the copper tubing it did (tubing is cheap, BTW). If 50 lbs is accurate, I would do something to up the pressure. New pump, comp springs, shim the stock spring, etc.