JMortensen

What concentration of tolulene are you using? I've used up to 20% tolulene and never had a problem with fuel lines melting.

I can only relate my experience, but that wasn't it. I had mild porting, big valve E31, and a medium cam and although you could hit 7000 rpm, it was a waste of time going much above 6200 with the SU's. Rebello puts their engines on their engine dyno, not a chassis dyno. If I saw a dyno chart that showed 275 whp for any L series running SU's big bore or otherwise I would need to see that dyno recalibrated and the car run again. johnc only made 287whp with MOTEC FI on a Sunbelt engine that was $25K or more IIRC.

You're right Norm. I think the early 240 had 6 counterweights, and the later one had 8 or something (SWAG here, might be way off). Should have said didn't have as many counterweights.

What happened to the car before you purchased it? Someone try to fix it and give up maybe? Sounds like somebody put the distributor shaft in in the wrong position. To fix that you'll need to pull the oil pump, take the shaft out rotate it to the right position, and put it back in. Easiest way is to have a person on top while you're on the bottom moving the shaft. Set it so the rotor points a little advance of the #1 spark plug terminal and you should be good to go. If you have an aftermarket sway bar you'll have to loosen the bushings on the frame on both sides. I think you can squeeze the shaft out if you're running the stock swaybar.

The earliest L24's didn't have a fully counterweighted crank. They stopped making that crank in the first part of 1970. Unless the car that the engine came out of were located I don't think it's going to make a difference as far as value...

I don't want to jack this thread, but what is a crush synchro? I thought I had everything I needed for mine, I got a rebuild kit with bearings, normal brass synchros, front and rear seals and the gasket for the front cover and a new main shaft nut. Am I good to go, or do I need the mysterious 5th gear crush synchro??? Is it like a crush sleeve or something? Confused...

PM Matman. He's not on here all day like me so he might not see this, but I know he has a couple sets of strut housings...

http://www.jrdemers.com/280ZX/distributor/distributor.html http://www.jrdemers.com/280ZX/distributor/ignition2.gif That page has instructions on tear down and inspection of the distributor. I would suggest that you take a look and consider at least tearing it down to inspect the vacuum advance mechanism which is almost always broken. The image has the wiring diagram on how to wire it up. Basically you run a wire from the neg coil terminal to the C connector on the module and the positive to the B connector. Conect the ballast to the positive as well. That's it. SUPER easy.

You're right. I made the first openly sarcastic comment. Sorry. Still a waste of money on a street/autox car like Mack's.

TC Rod FAQ The TC rod is an integral part of the Z suspension which locates the front control arm and controls the caster. It can be modified in various ways and these modifications are the subject of this post. Bushings can be changed, a nylon/aluminum cup assembly can be added, or a new adjustable arm can be substituted. This FAQ will try to address the common issues with these parts and hopefully will help you decide whether it is a part worthy of buying or not. WHAT IT DOES The TC rod takes the braking loads from the front suspension and transfers that load to the frame rails and into the structure of the car. The stock rubber bushings will give, and this give can be felt as a wandering under very hard braking. If you don’t intend on racing your Z you will probably never experience this feeling, and substituting any parts to fix this problem is probably a waste of money for you. ALTERNATIVES TO OLD STOCK RUBBER BUSHINGS New Rubber Bushings--The most obvious alternative is NEW stock rubber bushings. New bushings will help a lot, and the stock suspension is designed with the compliance of rubber bushings in mind. Installing new rubber bushings is an easy and safe way to improve your Z’s performance under braking. Polyurethane—Polyurethane bushings are a very common upgrade for Z cars. In the TC rod area they might not be the best choice however. In a control arm bushing the polyurethane allows the control arm to pivot up and down but prevents deflection. Deflection in the control arm bushings causes a mushy feeling and camber change in the front and can cause that same mushy feeling, camber change, and toe change in the rear. The TC pivot works differently. Unlike in the control arm bushing where the metal inner sleeve rotates inside the polyurethane, the TC rod pivoting through its arc FLEXES the bushing to allow movement. Since polyurethane is so much stiffer than stock rubber, moving the suspension through its range of motion puts a lot more stress on the end of the TC rod and there have been cases of the TC rod actually snapping due to these stresses over a period of time. Failures seem to be more common in the ZX and 510 suspension where the rod is in tension, but we have some reported cases at hybridz of Z’s having the same failure where the rod is in compression under braking. Possible fixes for this problem are to use a poly bushing in front and a stock rubber bushing in the back of the TC rod, since the front takes the braking load and the rear rubber bushing will allow the arm to pivot more easily, or even drilling holes in the poly bushing to give it some more compliance. G Machine Aluminum/Nylon bushing replacement—This system creates a joint that takes the place of the front bushing. This joint is made from aluminum cup and a nylon ball which pivot freely as the suspension moves. This is a pretty good option. The bushing in the back is not important for taking the load under braking, so using a rubber bushing in the rear ensures that the force required to move the suspension though its arc shouldn’t be more than stock. This does move the pivot slightly, which has other deleterious effects on the suspension, read more below to see what this involves. Adjustable TC Rods—One way of making the TC rods adjustable is to take the stock rod, cut it, and add a turnbuckle in the middle somewhere. If you choose this method you can use any of the bushing configurations above. The benefit to adding the turnbuckle is the ability to adjust caster. The stock rod is about the perfect diameter for running a 5/8" die down it. However when I tried this modification it became apparent that my rods were already bent. Your mileage may vary. Adjustable TC rods have been available through Arizona Z Car for years. Also one of our own moderators Mike Kelly used to make some (but does not any longer) and a new company called Techno Toy Tuning is selling these parts on ebay. There are others available as well. They all work basically the same way, although the designs differ slightly. The benefit to this style TC rod is adjustable caster, and that is a very significant benefit. The rear end of the TC rod uses a metal to metal rod end joint that attaches to a clevis. This clevis bolts in place of the stock front bushing. The rear bushing makes no difference at all and is usually (always?) eliminated because the pivot is provided by the rod end in this style setup. My understanding is that some of these use a polyurethane bushing behind the clevis. This would introduce a little flex into the system, and is done to reduce road noise and increase compliance. Most eliminate the front bushing as well and rely on the metal to metal joint to allow the suspension to move. There are some issues to be concerned with the heims jointed TC rods: 1. Wear. These are really race car parts and I don’t believe that any manufacturer of these arms recommends them for street use. They use a metal to metal joint that needs to be inspected regularly for wear. 2. NVH transfer to the chassis. I have had this type of TC rod in my car for years and I just inspected my frame rails and had no cracks, but there have been reports of cracking frame rails around the TC rod area, and the speculation is that this is due to the NVH transfer to the rail. If you install suspension parts that have no compliance it is necessary to inspect the suspension arms and chassis regularly. 3. Binding of the control arm bushing. As caster is added the control arm pivots forward. When you add a whole lot of caster the angle of the control arm can get pretty severe. This can result in binding in the control arm bushing. The bushing is pretty much straight at the factory caster setting of 3 degrees. If the goal is to add a whole lot of caster it is a good idea to use a custom lower control arm which also uses a rod end and allows for the control arm pivot to move freely. Torquing the lower control arm pivot by using poly and adding caster is a bad thing. 4. Binding of the bolts that locate the front of the TC rod. The bolt holes where the TC rod bolts to the control arm can also bind. When adjusting caster (always with the vehicle on it's wheels) it is a good idea to loosen the two front bolts when adding caster, then adjust the caster, then lock the two bolts down again. Doing this ensures that the end of the arm isn’t preloaded. It is theoretically possible to add so much caster that loosening the bolts and tightening them down doesn’t alleviate the load on the end of the arm. In this case it should be possible to open up the holes a bit to alleviate that pressure. The Arizona Z Car arms and some others come with a clevis at the front to attach the turnbuckle to the end of the arm which bolts to the control arm. The clevis is loosened, caster adjusted, then tightened. This eliminates any stress on this area of the arm from caster adjustments but relies on the smallish 3/8" bolt to connect the two pieces. 5. Semi-leading arm? The clevis type attachment that is universally used in these aftermarket arms extends the pivot out an inch or an inch and a half from the stock pivot location if bushings are used. This seems fairly inconsequential, but actually this turns the front suspension into a semi-leading arm. This causes the suspension to compress under braking loads. 6. Caster curve change. The shorter arm will also result in a more dramatic caster curve. As the TC rod goes past horizontal under braking or as the suspension compresses caster starts to fall off. 7. Camber curve change. Since the caster curve causes the caster to go positive as the TC arm goes past horizontal, it also affects the lower control arm as well. The control arm does not swing perpendicularly to the centerline of the vehicle. Instead it swings slightly forward until the TC rod is level then slightly back as the TC rod goes past horizontal. This change is more dramatic in cars using a clevis and a rod end, because the shorter arm requires more angle to move through its complete arc. 8. Dynamic wheelbase changes. Because of the changing caster curve, the wheelbase will actually change during the suspension’s movement as well. Benefits of the adjustable TC arm: 1. Adjustable caster. The stock Z front suspension is reluctant to turn in. Adding caster will make a very noticeable improvement in the vehicle’s ability to turn in, and the car will require less negative camber in the front end to keep tire temps consistent across the tread.. In my experience this benefit far outweighs the problems listed above. Some may not agree with my assessment, but that has been my experience. Benefits of the rod end TC arm: 1. Reduced stiction. Rod ends move freely throughout their range of motion. Unlike the rubber, polyurethane, or even the GMachine bushings, the rod ends have very little stiction in them and do not bind when installed correctly. The more freely the suspension moves the better the tires will stick to the road. OK, that’s about all I’ve got. You all found some errors in my last FAQ, so please point out anything amiss in this one. As always you work on your car at your own risk, and using racing parts on a street car is not condoned or recommended.

TC Rod FAQ The TC rod is an integral part of the Z suspension which locates the front control arm and controls the caster. It can be modified in various ways and these modifications are the subject of this post. Bushings can be changed, a nylon/aluminum cup assembly can be added, or a new adjustable arm can be substituted. This FAQ will try to address the common issues with these parts and hopefully will help you decide whether it is a part worthy of buying or not. WHAT IT DOES The TC rod takes the braking loads from the front suspension and transfers that load to the frame rails and into the structure of the car. The stock rubber bushings will give, and this give can be felt as a wandering under very hard braking. If you don’t intend on racing your Z you will probably never experience this feeling, and substituting any parts to fix this problem is probably a waste of money for you. ALTERNATIVES TO OLD STOCK RUBBER BUSHINGS New Rubber Bushings--The most obvious alternative is NEW stock rubber bushings. New bushings will help a lot, and the stock suspension is designed with the compliance of rubber bushings in mind. Installing new rubber bushings is an easy and safe way to improve your Z’s performance under braking. Polyurethane—Polyurethane bushings are a very common upgrade for Z cars. In the TC rod area they might not be the best choice however. In a control arm bushing the polyurethane allows the control arm to pivot up and down but prevents deflection. Deflection in the control arm bushings causes a mushy feeling and camber change in the front and can cause that same mushy feeling, camber change, and toe change in the rear. The TC pivot works differently. Unlike in the control arm bushing where the metal inner sleeve rotates inside the polyurethane, the TC rod pivoting through its arc FLEXES the bushing to allow movement. Since polyurethane is so much stiffer than stock rubber, moving the suspension through its range of motion puts a lot more stress on the end of the TC rod and there have been cases of the TC rod actually snapping due to these stresses over a period of time. Failures seem to be more common in the ZX and 510 suspension where the rod is in tension, but we have some reported cases at hybridz of Z’s having the same failure where the rod is in compression under braking. Possible fixes for this problem are to use a poly bushing in front and a stock rubber bushing in the back of the TC rod, since the front takes the braking load and the rear rubber bushing will allow the arm to pivot more easily, or even drilling holes in the poly bushing to give it some more compliance. G Machine Aluminum/Nylon bushing replacement—This system creates a joint that takes the place of the front bushing. This joint is made from aluminum cup and a nylon ball which pivot freely as the suspension moves. This is a pretty good option. The bushing in the back is not important for taking the load under braking, so using a rubber bushing in the rear ensures that the force required to move the suspension though its arc shouldn’t be more than stock. This does move the pivot slightly, which has other deleterious effects on the suspension, read more below to see what this involves. Adjustable TC Rods—One way of making the TC rods adjustable is to take the stock rod, cut it, and add a turnbuckle in the middle somewhere. If you choose this method you can use any of the bushing configurations above. The benefit to adding the turnbuckle is the ability to adjust caster. The stock rod is about the perfect diameter for running a 5/8" die down it. However when I tried this modification it became apparent that my rods were already bent. Your mileage may vary. Adjustable TC rods have been available through Arizona Z Car for years. Also one of our own moderators Mike Kelly used to make some (but does not any longer) and a new company called Techno Toy Tuning is selling these parts on ebay. There are others available as well. They all work basically the same way, although the designs differ slightly. The benefit to this style TC rod is adjustable caster, and that is a very significant benefit. The rear end of the TC rod uses a metal to metal rod end joint that attaches to a clevis. This clevis bolts in place of the stock front bushing. The rear bushing makes no difference at all and is usually (always?) eliminated because the pivot is provided by the rod end in this style setup. My understanding is that some of these use a polyurethane bushing behind the clevis. This would introduce a little flex into the system, and is done to reduce road noise and increase compliance. Most eliminate the front bushing as well and rely on the metal to metal joint to allow the suspension to move. There are some issues to be concerned with the heims jointed TC rods: 1. Wear. These are really race car parts and I don’t believe that any manufacturer of these arms recommends them for street use. They use a metal to metal joint that needs to be inspected regularly for wear. 2. NVH transfer to the chassis. I have had this type of TC rod in my car for years and I just inspected my frame rails and had no cracks, but there have been reports of cracking frame rails around the TC rod area, and the speculation is that this is due to the NVH transfer to the rail. If you install suspension parts that have no compliance it is necessary to inspect the suspension arms and chassis regularly. 3. Binding of the control arm bushing. As caster is added the control arm pivots forward. When you add a whole lot of caster the angle of the control arm can get pretty severe. This can result in binding in the control arm bushing. The bushing is pretty much straight at the factory caster setting of 3 degrees. If the goal is to add a whole lot of caster it is a good idea to use a custom lower control arm which also uses a rod end and allows for the control arm pivot to move freely. Torquing the lower control arm pivot by using poly and adding caster is a bad thing. 4. Binding of the bolts that locate the front of the TC rod. The bolt holes where the TC rod bolts to the control arm can also bind. When adjusting caster (always with the vehicle on it's wheels) it is a good idea to loosen the two front bolts when adding caster, then adjust the caster, then lock the two bolts down again. Doing this ensures that the end of the arm isn’t preloaded. It is theoretically possible to add so much caster that loosening the bolts and tightening them down doesn’t alleviate the load on the end of the arm. In this case it should be possible to open up the holes a bit to alleviate that pressure. The Arizona Z Car arms and some others come with a clevis at the front to attach the turnbuckle to the end of the arm which bolts to the control arm. The clevis is loosened, caster adjusted, then tightened. This eliminates any stress on this area of the arm from caster adjustments but relies on the smallish 3/8" bolt to connect the two pieces. 5. Semi-leading arm? The clevis type attachment that is universally used in these aftermarket arms extends the pivot out an inch or an inch and a half from the stock pivot location if bushings are used. This seems fairly inconsequential, but actually this turns the front suspension into a semi-leading arm. This causes the suspension to compress under braking loads. 6. Caster curve change. The shorter arm will also result in a more dramatic caster curve. As the TC rod goes past horizontal under braking or as the suspension compresses caster starts to fall off. 7. Camber curve change. Since the caster curve causes the caster to go positive as the TC arm goes past horizontal, it also affects the lower control arm as well. The control arm does not swing perpendicularly to the centerline of the vehicle. Instead it swings slightly forward until the TC rod is level then slightly back as the TC rod goes past horizontal. This change is more dramatic in cars using a clevis and a rod end, because the shorter arm requires more angle to move through its complete arc. 8. Dynamic wheelbase changes. Because of the changing caster curve, the wheelbase will actually change during the suspension’s movement as well. Benefits of the adjustable TC arm: 1. Adjustable caster. The stock Z front suspension is reluctant to turn in. Adding caster will make a very noticeable improvement in the vehicle’s ability to turn in, and the car will require less negative camber in the front end to keep tire temps consistent across the tread.. In my experience this benefit far outweighs the problems listed above. Some may not agree with my assessment, but that has been my experience. Benefits of the rod end TC arm: 1. Reduced stiction. Rod ends move freely throughout their range of motion. Unlike the rubber, polyurethane, or even the GMachine bushings, the rod ends have very little stiction in them and do not bind when installed correctly. The more freely the suspension moves the better the tires will stick to the road. OK, that’s about all I’ve got. You all found some errors in my last FAQ, so please point out anything amiss in this one. As always you work on your car at your own risk, and using racing parts on a street car is not condoned or recommended.

OK, let's take a step back. Mack says this is going to be a street/autox car. Do you think your super-wazoo cooler is necessary for street/autox car? I stated my own years of experience, but I actually have quite a bit more than my own experience to fall back on. My friends with 510s have been using Nissan LSD's for longer than I have. None has an oil cooler. All run DOT's or slicks. All have MUCH more track experience than I do, as well as close to a decade more autox experience. Not one has had a diff failure that I'm aware of, but I've only been privy to their parts failures for the last 15 years or so, so admittedly there might have been something in the late 80s that happened that I'm not aware of. I haven't seen it in a long time, but I am pretty darn sure that the Nissan Comp catalog from about 10 years ago had a picture of the diff cooler system, and that it sucked out of the lower port in the cover and returned to the higher port in the housing. I'm 99.9999% sure. You can drill a hole in the housing and add a fitting or whatever you want to do on your car. Please post a thread with your results when you're done. But that's not the way the Nissan Comp oil cooler worked IIRC. Cooler fluid in the sump gets recirculated through the diff by the ring gear. That was the idea. The oil is a coolant as well as a lubricant. You're right about that. I guess the question is how much heat is too much, and how much expense is justified in trying to "fix" this "problem". That's where we disagree. Unfortunately, as is your MO, you seem to be intent on calling anyone who disagrees with you patently wrong. That's the part I take issue with.

Yep, that's right. Cheap and it's only lasted through 6 years of autoxing at least monthly and a whole bunch of track days. You'll see very quickly that downshifting is an essential part of slowing a Z down on a track, so I always do that. As for tires... well I'm running 250/45/15 Yokohama A005 slicks so I think I could say that I can and have generated some heat back there, although I did start with street tires then move to DOTs, so it only really had 4 YEARS of the slicks. I suggest you spend your money where it's needed. But it's your $$$.

To directly answer your question of why I did what I did, I did it as part of another project. I wanted adjustable toe and figured while am at it I might as well add the finned sump: http://forums.hybridz.org/showthread.php?t=89111 Cost: $8.

Waste of time/money.

Hmm. All this time I thought oil coolers were intended to cool the oil and only indirectly affect the housing temperature. Seems to me a water jacket and coolant sytem would be a better way to cool the housing... maybe you ought to get to work on that. I used the stock 280Z cover with my LSD and did as many as 12 1/2 hours sessions in one day with 3 drivers and never had any problems with my diff or LSD not functioning correctly. Now that I shimmed mine up I added the finned cover and I'm hoping that the increased sump capacity and the little bit of cooling that the finned cover provides will be sufficient. Hopefully you'll have your water cooled diff sorted by the time I have a failure in the case that I'm wrong.

Not a problem with the arms I have, and I ran 5.5 degrees caster. As long as the bolts don't bind in the holes this isn't an issue. Just loosen the bolts, adjust the caster, and lock the bolts down again. Even if they did bind up, you could theoretically just grind out the bolt holes a bit to cure that. You do have a point though, and when I redo my TC rods I will be incorporating a clevis into the design. Mike makes a good point. I had custom LCAs made because the caster I was running was binding the poly front bushings I was using at the time. A rod end at the LCA pivot is a very good idea. This is all rehashing the same old BS over and over though. Maybe we need a sticky or a FAQ that explains all this crap. I swear we've done this technotoytuning thing at least 3 times, and the title was almost exactly the same every time. We should require more searching outta the newbies...

Your diff won't get hot enough at autox to justify the expense of a diff cooler. If you have a 280ZX you might consider just getting the 300ZX turbo diff cover. I think it bolts right on to the ZX (the Z has some clearance issues) it's aluminum and finned which should have better heat transfer properties, and it about doubles the sump capacity. It also has some areas on the side that are cast for a cooler inlet and outlet, but they don't drill and tap the cover on the 300 ZXT. Easy enough to drill and tap the holes if you still felt like you needed an external cooler. It returns the oil straight to the sump, not to the gears.

They are the same size, and you'd shorten them because of the problem John Coffey describes on his website. http://www.betamotorsports.com/benchracing/index.html Click on R200 handling issues.

Nope. Plenty of guys running 14's that don't have 3.5 degrees of camber. I don't think I've ever seen positive camber in the back of a Z, even at stock height they're more like 0 degrees in the back and a little positive in the front IIRC. Something is wrong. This may sound really retarded, and I don't mean to insult you, but it almost sounds like you're measuring the camber with the car up in the air. You do have it on the ground, and you've rolled it around a bit to settle the suspension since you put in the struts/springs, right???

Click... Whoooooooooooosh... Phewwwwwwww... Ahhhh... Ah, the sounds of the crack pipe...

There should be no way that your lowered Z has positive camber. Most lowered Z's end up with way too much negative camber. Something isn't right.

Uh, don't think so. Either it's neg camber where the tires are closer together at the top than the bottom, or you have something seriously wrong with your suspension. -3.5 is going to wear out tires, and your front end needs more neg camber to work at autox.

Not IME. I got great life out of my pads, except the ones that went to the track. If you turn a drilled rotor (yes you can, I've done it) then you need to chamfer all of the holes or they will act like a cheese grater on the pad.