JMortensen

My TC rods weren't so bad you could feel it while driving, although I suppose that could happen, probably hear a clunk when you went from reverse to 1st gear. There was some galling on one of the rod ends and it was really up inside the joint so you couldn't see it, but if you took it off you could feel that it was pretty tight to move. The other side was on the loose side, with just a hint of play in it. I think to inspect them you can feel play by jiggling the suspension, but if you wanted to find that galled monoball you'd really have to take the suspension apart and move it by hand.

There was one post here where someone suggested that you should really check your chassis for stress cracks WEEKLY if you are running heims. My opinion is that is BS. I did have a crack in my frame, but that looked to me as though it was due to the PO running over a curb (frame rail was really badly dented and floor pushed in a bit on that side). No cracks in the strut tower, crossmember or TC buckets on my car after 40K miles on heims 6 seasons of autox and a bunch of track days. You need to take care of your own car and be responsible for your own decisions, but the idea that using heims tears up the car is counter to my personal experience. In light of the way I used the Z I think it was well worth it to run it on the street with heims. YMMV depending on what you're planning to do. If you're just driving to work and home it might be money that you get better return on with engine mods.

Bushings, either poly or rubber, will take quite a bit of misalignment before they really start binding up from it. The poly has so much stiction though that some of us have gone to monoballs for the inner and outer pivots. That's on another thread: http://forums.hybridz.org/showthread.php?t=106457

Or a helical LSD that functions normally.

If you're using bump steer spacers I don't think you'll have much room at all. If you get rid of the spacers, then you'll have a little room, but not much. My experience says you only need about 1/2" of LCA movement to fix the problem, so you'd probably need the same on the tie rod side if your LCA pivot hole is stock. My guess is you could squeeze that in, but it will probably be tight. That is just a guess.

Do an X from the rear strut towers to the base of the hoop. That should take care of the package area being damaged by the PO. I drove my car with heims jointed front LCA's and TC's and monoballs in the camber plates daily for years. Only issue I had was loose camber plate monoballs in the rear really make a racket right behind your head. I had 3/4" rod ends on the TCs and they were probably due for a change after 5 years on the road. The LCAs were 5/8 but newer but didn't need to be replaced during the several years that I used them daily.

Well at least you made it worth their while...

Oil shaft is the same. The only thing that I'm aware of that may be a problem is the part that bolts to the timing cover that holds the distributor I think also needs to be changed, but I don't think you'd have it running if that were the problem.

Your estimated cg heights sound high to me. That's the problem with estimating I guess. It might be nice to see if anyone had a known cg height. Some corner weight scales do that calculation, so maybe someone here already has it. I seem to remember 260DET saying that the ZX had a cg height that was the same as the output shaft of the transmission for some reason, and the straight 6 should have a higher cg than a V8. It's tough to extrapolate that out, but 19" just sounds really high...

Clutch LSD tries to lock the wheels together. If you spin one side the opposite side moves in the same direction and you'd have to hold one side still and exceed the breakaway pressure of the LSD to spin them at different rates or in different directions. Unfortunately this doesn't apply to gear driven LSDs. The best test is to take it out and look, but barring that do some donuts and see what happens. If it spins the inside tire, then you need a (better) LSD. IRS tends to spin both tires, unlike a solid axle, so the fact that you got two stripes doesn't mean a thing.

I think Smith's equation is a generalization. You'll get an idea of weight transfer from it, but just thinking of the related issues I can come up with several things it doesn't account for, like cg height changing under different conditions, weight changing under different conditions, and of course the g loading changing. Track width on a Z changes too as the suspension compresses, so that too could change. Use the formula as an estimate not a concrete answer.

I don't think you can get that much more acceleration out of AWD. When you accelerate you don't have 50% more traction at the front because weight transfer moves available traction to the rear. This is why you have 80/20 splits on power distribution on higher hp AWD cars. I think you might have 20-30% more traction in pure WOT acceleration from a stop, and perhaps a bit more when you're not WOT but are pushing on the accelerator mid corner.

Really? That is your argument? Racing is about traction, not efficiency as you said. Are we not arguing about race cars in this thread??? Let's completely ignore that for a minute and ask another question. Why do you think FWD is more efficient? I'm guessing that it has to do with the lack of a drivetrain that goes from one end of the car to the other. Guess what mid or rear engine RWD cars don't have? How does this affect your efficiency argument now? Does this ruin your argument?

You can adjust the aperture on the Unisyn. If it's all the way open there may just not be enough vacuum to make it function.

Try a picklefork and a BFH. The picklefork is usually less than $5 at the parts store.

Just guessing, but they're probably the same or close enough on any CV or stub shaft. That might widen your available sources.

Don't hit the stud with a hammer, or the threads will mushroom and it won't come out, as jtburf said. The way to remove a tie rod with a hammer is to hit the STEER KNUCKLE. A ball joint separator or pickle fork will work, pickle fork will probably take out the boot so if you want to reuse you probably want the ball joint separator.

I too was thinking Corvette Summer. WTF did they do with the roll bar? I can't figure it out, but it looks FUBAR.

I wasn't addressing you in particular, but I also don't think you can engineer the physics completely away. There IS traction available that a 2wd car can't use than an AWD can. There IS weight transfer that can't be avoided when the cg is above ground. Until we're driving slot cars with a huge weight hanging down into the slot, I don't think you can avoid the transfer of weight off the drive wheels. Now you may get around that at high speeds by putting a gigantic wing on the front of the car, and again, I think credit is due to this guy for thinking out of the box and having the balls to do it. Put a huge wing on the front of a RWD car and (not comparing directly to this FWD car but just making a general statement) it will have more grip up front for the turns and braking as well and can still use a second huge wing in the back for grip under acceleration and braking too. Put one on an AWD car and now you have more grip at BOTH ends for braking and acceleration and turning. Again, seems to be a clear advantage. I'm asking here, because I don't know: What is the highest dollar unlimited class racing you can find? I'd guess Pikes Peak. What do the Suzuki and Toyota's run? FWD? RWD? AWD? WHY? Agreed there.

I can't believe what is going on in this thread. ONE guy has a screaming fast FWD car and all of a sudden you have a bunch of people who are RWD car enthusiasts praising the FWD platform as if it were the greatest platform around. I think Tony's example says it best. The reason the FWD car is so fast is because the guy ISN'T BUILDING TO A RULESET. He can do whatever the hell he wants. That opens up endless possibilities, and unconventional thinking has clearly ruled the day. To compare his car built to no ruleset vs another built to no ruleset is also fairly meaningless, unless you're looking for a science fair type of thing where my science project > your science project. So far, this guy has the best science project, and that is really cool, but it doesn't mean that his platform is intrinsically the best. He's only being beaten by the open wheel cars, right? What wheel drive are they? WHY? Read the Millikens' book or any kind of basic racing principles book by Carroll Smith, etc, and you'll find that FWD is not the preferred platform because as you accelerate the weight shifts off the drive wheels and they are also responsible for the majority of (and carry more of the weight during) braking and turning. AWD has a CLEAR advantage over either FWD or RWD because when the 2WD can't put any more power down to the drive wheels there is UNUSED traction available at the other end that it can take advantage of.

There isn't enough headroom in a Z for a streetable cage IMO, unless you're really short, in which case it's fine so long as you don't carry passengers who are taller than 5'4" or whatever turns out to be safe. If you're not short, I think you're more likely to get killed in a very minor accident with an Escalade (or a Toyota Echo) when you smack your head on the cage. I think the Z is pretty good in accidents, for as old a car as it is. I was in an accident with my first 72 240Z where I was hit from the rear at ~50 mph (driver of the Firebird never saw me and never even touched the brakes). I was then pushed across the street into head on traffic where I hit an Acura Legend who was going probably 30 mph. The Z performed pretty admirably. My wife hit her head on the dashboard despite wearing the shoulder harness and I broke my nose on the steering wheel (wearing lap belt at the time). The unibody was tweaked pretty bad, but the passenger compartment was relatively intact. In fact the rear end of the car was pushed in about a foot and a half and when the cops got there they asked if my lights and turn signal were on, I looked at my car in the street and said "They still are!" The lens was broken but all of the bulbs were still lit and the turn signal was still flashing. As far as the cage goes, I think it's tough to model the entire unibody in a computer program, but you can model the cage for strength pretty easily in the computer and you can also physically model the cage with wood or wire and test it for rigidity in scale. I came upon my weird cage design after reading Herb Adams' Chassis Engineering. My cage is in there on page 90 only I have X door bars and an X from the rear strut towers to the bottom of the main hoop. I agree wholeheartedly that sometimes designs have a bunch of extra tubes for nothing, and sometimes it's hard to tell at first glance that those tubes really are doing something. I think the basic ideas of cage building are pretty well established and you can do a "monkey see monkey do" cage that does a fine job. If you want to get really anal about it, there are places online for that as well. Read any post by "blainefab" on corner-carvers.com, for instance...

Who is Jim?

Both axles need to turn in THE SAME DIRECTION. If you can jack up the back of the car, you would also be able to try and turn them in opposite directions. It should be possible, but takes a lot of force with the LSD. An open diff will easily spin the tires in opposite directions.

Got it done today. I used a cartridge roll on a die grinder to open up the pilot on the rotors, then shimmed them. The first needed one adjustment after the initial attempt, I was done with it pretty quickly. The second was much worse, it was .024" out of true. I had to stack shims as my hole punch wouldn't work on metal thicker than .007 (and just barely worked on .007). Once I did my initial shimming I found when I tightened it down I had gone way too far, so had to back it off quite a bit. Needess to say it took several hours for the second rotor, but now all 4 have runout of .002 or less. Thanks for all the help. I guess the thing to learn from my experience is that if the rotor or hat is tight on its ID, that will throw everything off.

The key is to have a SHARP bit and use CUTTING FLUID, not WD-40. I used bacon grease as a cutting fluid. Worked great. Before the fluid I burned up two bits and thought it was impossible. With the grease the drill just cut right through in about 2 minutes.